Please look in Eschmeyer's Catalog of Fishes for authorships of sections, Families of Fishes (all), and related information.

Species in the family or subfamily Rivulidae: [ 550 ] records

accorsii, Austrolebias Nielsen [D. T. B.] & Pillet [D.] 2015:174, Figs. 1-2 [aqua, International Journal of Ichthyology v. 21 (no. 4); ref. 34011] Departamento de Santa Cruz de La Sierra, temporary pool, Río Grande basin (trib. to Río Mamore basin), 18°39'26.2"S, 62°58'0.2"W, Bolivia, altitude 366 meters. Holotype: ZUEC 10792. Paratypes: 10793 (19), •Valid as Austrolebias accorsii Nielsen & Pillet 2015 -- (Alonso et al. 2016:6 [ref. 34643], Volcan & Severo-Neto 2019:548 [ref. 36539], Alonso et al. 2023:10 [ref. 40292], Drawert 2023:9 [ref. 40730], Drawert & Ergueta 2024:5 [ref. 41211]). Current status: Valid as Austrolebias accorsii Nielsen & Pillet 2015. Rivulidae: Cynolebiinae. Distribution: South America: upper Iténez/Guaporé River drainage, southern of the Chiquitos montain range, Bañados del Izozog wetlands, Tunas and Quimome River drainages, Cordillera Province, Santa Cruz Department, Bolivia. Habitat: freshwater.

acutirostratus, Neofundulus Costa [W. J. E. M.] 1993:616, Fig. 1 [Revista Brasileira de Biologia v. 52 (no. 4) (for 30 Nov. 1992); ref. 21314] Lagoa Santa, Rio São Francisco basin, Minas Gerais State, Brazil. Holotype (unique): CAS-SU 68326. •Valid as Neofundulus acutirostratus Costa 1993 -- (Costa 1998:78 [ref. 23792], Lazara 2001:215 [ref. 25711], Costa in Reis et al. 2003:532 [ref. 27061], Nielsen & Brousseau 2013:114 [ref. 32795]). Current status: Valid as Neofundulus acutirostratus Costa 1993. Rivulidae: Rivulinae. Distribution: Das Velhas River basin, Brazil. Habitat: freshwater.

adloffi, Cynolebias Ahl [E.] 1922:224 [4], Figs. [Blätter für Aquarien- und Terrarienkunde v. 33 (no. 14); ref. 15334] Porto Alegre, Estado do Rio Grande do Sul, Brazil. Lectotype: ZMB 20651. Paralectotypes: (4 missing) ZMB 20652 (2), 31426 [ex ZMB 20651] (1). Type catalog: Paepke & Seegers 1986:156 [ref. 19981] including lectotype designation. Types mentioned: Paepke 1995:94 [ref. 21847]. On p. 4 of separate. •Valid as Cynolebias adloffi Ahl 1922 -- (Malabarba 1989:158 [ref. 14217] as addloffi, Costa 1995:74 [ref. 22097]). •Valid as Austrolebias adloffi (Ahl 1922) -- (Costa 1998:75 [ref. 23792], Lazara 2001:59 [ref. 25711], Costa & Cheffe 2001:190 [ref. 25851], Costa 2002:917 [ref. 26505], Costa in Reis et al. 2003:527 [ref. 27061], Lourerio et al. 2004:27 [ref. 27658], Costa 2006:126 [ref. 28708], Loureiro & García 2008:10 [ref. 30099], Costa 2009:188 [ref. 30417], Volcan et al. 2014:167 [ref. 33543], Bertaco et al. 2016:423 [ref. 34561], Nión et al. 2016:42 [ref. 35565], Costa et al. 2017:142 [ref. 35626], Loureiro et al. 2018:11 [ref. 36240], Volcan et al. 2021:104 [ref. 38292], Giora & Wingert 2023:27 [ref. 41026]). •Valid as Garcialebias adloffi (Ahl 1922) -- (Alonso et al. 2023:13 [ref. 40292]) Current status: Valid as Garcialebias adloffi (Ahl 1922). Rivulidae: Cynolebiinae. Distribution: South America: southeastern Brazil. Habitat: freshwater.

adornatus, Simpsonichthys Costa [W. J. E. M.] 2000:9, Figs. 1-2 [Aquarium (Brasil) v. 3 (no. 25); ref. 25933] Temporary pool, near Sítio do Mato, rio São Francisco basin, Bahia State, Brazil, 13°00'46.1"S, 43°28'50.0"W, elevation 463 meters. Holotype: MZUSP 54563. Paratypes: MCP 22262 (20); MZUSP 54564 (10); UFRJ 4805-07 (18, 1, 8), 5188-89 (20, 10). •Valid as Simpsonichthys adornatus Costa 2000 -- (Costa in Reis et al. 2003:540 [ref. 27061], Costa 2006:17 [ref. 28620], Costa 2007:85 [ref. 29445], Nielsen et al. 2010:57 [ref. 30828]). •Valid as Hypsolebias adornatus (Costa 2000) -- (based on generic placement in Costa 2011 [ref. 31654], Costa 2013;141 [ref. 33008], Nielsen et al. 2014:28 [ref. 33143], Nielsen et al. 2014:132 [ref. 33451], Silva et al. 2020:14 [ref. 37809]). Current status: Valid as Hypsolebias adornatus (Costa 2000). Rivulidae: Cynolebiinae. Distribution: South America: São Francisco River basin (Bahia State, Brazil). Habitat: freshwater.

adrianae, Argolebias Alonso [F.], Terán [G. E.], Calviño [P.], Serra [W. S.], Montes [M. M.], García [I. D.], Barneche [J. A.], Ciotek [L.], Giorgis [P.] & Casciotta [J. R.] 2024:301, Figs. 1-4, 5F-I, 6, 11 [Canadian Journal of Zoology v. 102 (no. 3); ref. 40863] Seasonal ponds of the waterfall Arrechea stream, tributary of lower Iguazú River, near Km 2 of Macuco trail, Parque Nacional Iguazú, Misiones Province, north-east Argentina, circa −25.663556, 54.452917, elevation 185 meters. Holotype: IBIGEO I476. Paratypes: CI-FML 7948 (7), IBIGEO I477 (18). •Valid as Argolebias adrianae Alonso, Terán, Calviño, Serra, Montes, García, Barneche, Ciotek, Giorgis & Casciotta 2024. Current status: Valid as Argolebias adrianae Alonso, Terán, Calviño, Serra, Montes, García, Barneche, Ciotek et al. 2024. Rivulidae: Cynolebiinae. Distribution: South America: seasonal ponds of the lower Iguazú River drainage, Parque Nacional Iguazú, Misiones Province, north-east Argentina. Habitat: freshwater.

adrianae, Rivulus Vermeulen [F. B. M.] 2022:6, Figs. 1-2, 4-5, 10 [Killi-Data Series 2022; ref. 39817] Sipaliwini River, a tributary of the Courantyne River, Sipaliwini District, southwest Suriname, 2°20'57.03"N, 56°47'8.75"W, elevation 218 meters. Holotype: NZCS F7105. Paratype: NZCS F7106 (7). Genus tentative. •Valid as Anablepsoides adrianae (Vermeulen 2022). Current status: Valid as Anablepsoides adrianae (Vermeulen 2022). Rivulidae: Rivulinae. Distribution: South America: Sipaliwini River drainage, Courantyne River basin, southwest Suriname. Habitat: freshwater.

affinis, Cynolebias Amato [L. H.] 1986:6, Pl. 3 (figs. 5-6) [Comunicaciones Zoologicas del Museo de Historia Natural de Montevideo v. 11 (no. 162); ref. 9170] Floodlands of Tres Cruces Creek, route 5, kilometers 399.5, Tacuarembó, Uruguay. Holotype: MHNM 2468. Paratypes: MHNM 2469-73 (1, 86, 212, 1, 2); MZUSP 36448-49 (1, 1). Type catalog: Loureiro et al. 2016:412 [ref. 35150]. •Valid as Cynolebias affinis Amato 1986 -- (Costa 1995:65 [ref. 22097], Murphy & Collier 1997:797 [ref. 25585], Costa 1999:301 [ref. 24229], Costa 1999:93 [ref. 24131]). •Valid as Austrolebias affinis (Amato 1986) -- (Costa 1998:75 [ref. 23792], Lazara 2001:59 [ref. 25711], Costa 2002:917 [ref. 26505], Costa in Reis et al. 2003:527 [ref. 27061], Perujo et al. 2005:3 [ref. 28452], Costa 2006:71 [ref. 28708], Costa 2009:188 [ref. 30417], Litz & Koerber 2014:29 [ref. 33622], Koerber & Litz 2014:5 [ref. 34967], Koerber & Litz 2016:7 [ref. 35098], Nión et al. 2016:42 [ref. 35565], Loureiro et al. 2018:11 [ref. 36240], Koerber et al. 2020:8 [ref. 37480], Koerber et al. 2021:9 [ref. 38894], Loureiro et al. 2023:166 [ref. 40506]). •Valid as Matilebias affinis (Amato 1986) -- (Alonso et al. 2023:9 [ref. 40292], Koerber et al. 2023:11 [ref. 40355]). Current status: Valid as Matilebias affinis (Amato 1986). Rivulidae: Cynolebiinae. Distribution: South America: Negro River basin (Uruguay). Habitat: freshwater.

agilae, Rivulus Hoedeman [J. J.] in Gols 1954:202, Fig. [Het Aquarium v. 24 (no. 9); ref. 33273] Agila, rivulet between Agila at Suriname River and Berlijn at Para River, Suriname. Holotype: ZMA 100448a. Paratypes: BMNH 1957.1.28.13-18 [ex ZMA] (6), 1958.9.2.110-111 [ex ZMA] (2); RML 1-4-53 (179); ZMA 100448b (1), 100449 (8). Type catalog: Nijssen et al. 1982:70 [ref. 19236]. •Valid as Rivulus agilae Hoedeman 1954 -- (Huber 1991:70 [ref. 19721], Huber 1992:87 [ref. 20639], Huber 1999:50 [ref. 23834], Keith et al. 2000:36 [ref. 24547], Lazara 2001:269 [ref. 25711], Costa in Reis et al. 2003:534 [ref. 27061], Suijker & Collier 2006:10 [ref. 28729], Keith et al. 2006:137 [ref. 28851], Costa 2006:152 [ref. 28875] in subgenus Laimosemion). •Valid as Laimosemion agilae (Hoedeman 1954) -- (Costa 2011:239 [ref. 31655], Vermeulen et al. 2012:188 [ref. 32253], Valdesalici & García Gil 2015:169 [ref. 34010], Taphorn et al. 2022:36 [ref. 41297]). Current status: Valid as Laimosemion agilae (Hoedeman 1954). Rivulidae: Rivulinae. Distribution: South America: Atlantic coastal river basins (French Guiana, Guyana and Suriname). Habitat: freshwater.

aithogrammus, Melanorivulus Nielsen [D. T. B.] & Britzke [R.] 2019:36, Figs. 1-2 [aqua, International Journal of Ichthyology v. 25 (no. 1); ref. 36525] Igarapé da Aldeia, Rio Tapajós basin, Itaituba, Pará, Brazil, 4°42'55"S, 56°26'25"W. Holotype: MZUSP 123088. Paratypes: LBP. •Valid as Melanorivulus aithogrammus Nielsen & Britzke 2019. Current status: Valid as Melanorivulus aithogrammus Nielsen & Britzke 2019. Rivulidae: Rivulinae. Distribution: South America: Rio Tapajós basin, Parque Nacional da Amazônia, Pará, Brazil. Habitat: freshwater.

akroa, Cynolebias Nielsen [D. T. B.], Martins [M.], Araujo [L. M. de], Lira [F. O. de] & Faour [A.] 2018:114, Figs. [aqua, International Journal of Ichthyology v. 23 (no. 4) [for 15 Mar. 2018]; ref. 35996] Temporary pools from the Rio Preto drainage, São Francisco basin, Bahia, Brazil. Holotype. Paratypes: •Valid as Cynolebias akroa Nielsen, Martins, Araujo, Lira & Faour 2018. Current status: Valid as Cynolebias akroa Nielsen, Martins, Araujo, Lira & Faour 2018. Rivulidae: Cynolebiinae. Distribution: Rio Preto drainage, São Francisco basin, northeastern Brazil. Habitat: freshwater.

alba, Cynolebias luteoflammulatus var. Reichert [J. J.], García [G.], Wlasiuk [G.] & Prieto [F.] 1998:97, figs. 2-4 + 1 unnumbered fig. [DKG-Journal v. 30 (no. 5); ref. 31462] Ruta 14, Paso del Gringo, Rocha, Uruguay. Syntypes: (2) DZVU 556-7 (1, 1). Described as a variety after 1960; therefore considered as an infrasubspecific name and not available (ICZN Art. 10.2). •In genus Acantholebias. Infrasubspecific. Rivulidae: Cynolebiinae.

albae, Rivulus Valdesalici [S.], García Gil [J. R.] & Bressane Nielsen [D. T.] 2011:106, Figs. 1-2 [Vertebrate Zoology v. 61 (no. 1); ref. 31381] Lago Comprido floodplains, Pozo Bacabae, 1°44.270'N, 50°50.904'W, Estado de Amapa, Brazil, elevation 8 meters. Holotype: MZUSP 108783. Paratypes: MTD F 32342 (1), 32343 (1); MSNG 56259 a+b (2), 56259c-d (2, c&s); MZUSP 108784 (1). •Synonym of Melanorivulus schuncki (Costa & De Luca 2011) -- (Bragança et al. 2012:51 [ref. 32067]). Current status: Synonym of Melanorivulus schuncki (Costa & De Luca 2011). Rivulidae: Rivulinae. Distribution: Comprido Lake and Tartaruga Grande River, Brazil [if valid]. Habitat: freshwater.

albipunctatus, Cynolebias Costa [W. J. E. M.] & Brasil [G. C.] 1991:58, Fig. 3 [Ichthyological Exploration of Freshwaters v. 2 (no. 1); ref. 16651] Temporary pool, 70 kilometers nw from the City of Uauá, County of Juazeiro, Bahia, Brazil. Holotype: MZUSP 41378. Paratypes: MZUSP 41379 (9). •Valid as Cynolebias albipunctatus Costa & Brasil 1991 -- (Costa 1995:82 [ref. 22097], Costa 1998:238 [ref. 23578], Costa 1998:76 [ref. 23792], Lazara 2001:77 [ref. 25711], Costa 2001:355 [ref. 25719], Costa in Reis et al. 2003:529 [ref. 27061], Costa 2009:146 [ref. 30511]). •Synonym of Cynolebias porosus Steindachner 1876 -- (Costa 2014:69, 71 [ref. 33510]). Current status: Synonym of Cynolebias porosus Steindachner 1876. Rivulidae: Cynolebiinae. Distribution: Middle São Francisco River basin, Brazil (if valid). Habitat: freshwater.

alexandri, Cynolebias Castello [H. P.] & López [R. B.] 1974:35, Fig. [Tropical Fish Hobbyist v. 23 (no. 1); ref. 17] Parque Unzue, Gualeguaycú, Province de Entre Ríos, Argentina. Holotype: MACN 6438. Paratypes: MACN 2738 (7 or 9), 6425 (7), 6437 (4), 6439 (1). Type catalog: Braga & Piacentino 1994:98 [ref. 23697] as alexandrii. •Valid as Cynolebias alexandri Castello & López 1974 -- (Costa 1995:64 [ref. 22097], Costa 1999:301 [ref. 24229], Costa 1999:93 [ref. 24131]). •Valid as Austrolebias alexandri (Castello & López 1974) -- (Costa 1998:75 [ref. 23792], Lazara 2001:59 [ref. 25711], Costa 2002:917 [ref. 26505], Costa in Reis et al. 2003:527 [ref. 27061], López et al. 2003:69 [ref. 27366], Menni 2004:86 [ref. 28131], Calviño 2005:15 [ref. 28325], Perujo et al. 2005:2 [ref. 28452], Calviño 2006:183 [ref. 28679], Costa 2006:60 [ref. 28708], Costa 2009:188 [ref. 30417], Litz & Koerber 2014:29 [ref. 33622], Mirande & Koerber 2015:50 [ref. 35117], Calviño et al. 2016:8 [ref. 34699], Bertaco et al. 2016:423 [ref. 34561], Nión et al. 2016:42 [ref. 35565], Volcan et al. 2017:150 [ref. 35644], Loureiro et al. 2018:11 [ref. 36240], Loureiro et al. 2023:165 [ref. 40506]). •Valid as Matilebias alexandri (Castello & López 1974) -- (Alonso et al. 2023:9 [ref. 40292], Koerber et al. 2023:11 [ref. 40355], Koerber et al. 2023:4 [ref. 40368]). Current status: Valid as Matilebias alexandri (Castello & López 1974). Rivulidae: Cynolebiinae. Distribution: South America: Uruguay River basin (Argentina, Brazil and Uruguay). Habitat: freshwater.

altamira, Plesiolebias Costa [W. J. E. M.] & Nielsen [D. T. B.] in Costa 2007:25, Figs. 16-17 [Zootaxa No. 1410; ref. 28993] Temporary pool in island, rio Xingu, in front of Altamira, 3°13'34.6"S, 52°12'26.1"W, Estado do Pará, Brazil. Holotype: UFRJ 6369. Paratypes: UFRJ 6370 (1), 6371 (3, c&s). The second author is D. T. B. Nielsen. •Valid as Plesiolebias altamira Costa & Nielsen 2007. Current status: Valid as Plesiolebias altamira Costa & Nielsen 2007. Rivulidae: Rivulinae. Distribution: Seasonal pools near Altamira, Xingu River drainage, Amazon River basin, Estado do Pará, Brazil. Habitat: freshwater.

alternatus, Cynolebias Costa [W. J. E. M.] & Brasil [G. C.] 1994:7, Fig. 4 [Revue française d'Aquariologie Herpétologie v. 21 (no. 1/2); ref. 21598] João Pinheiro, near Rio Paracatú, near city of Brasilândia, Rio São Francisco basin, about 17°02'52.0"S, 46°01'34.0"W, Minas Gerais State, Brazil, elevation 560 meters. Holotype: MNRJ 12523. Paratypes: MNRJ 12524 (2); MZUSP 46082 (3); UFRJ 2129-30 (1, 11), 2131 (4, c&s). •Valid as Simpsonichthys alternatus (Costa & Brasil 1994) -- (Costa 1996:130 [ref. 25271], Costa 1998:75 [ref. 23792], Costa & Nielsen 2000:7 [ref. 24442], Lazara 2001:295 [ref. 25711], Costa 2003:51 [ref. 26768], Costa in Reis et al. 2003:540 [ref. 27061], Costa 2006:17 [ref. 28620], Costa 2007:122 [ref. 29445], Costa 2008:156 [ref. 29874]). •Valid as Hypsolebias alternatus (Costa & Brasil 1994) -- (based on generic placement in Costa 2011 [ref. 31654]). Current status: Valid as Hypsolebias alternatus (Costa & Brasil 1994). Rivulidae: Cynolebiinae. Distribution: Paracatu River floodplains, São Francisco River basin, Minas Gerais State, Brazil. Habitat: freshwater.

altivelis, Rivulus Huber [J. H.] 1992:93, Fig. 29a [Review of Rivulus: Ecobiogeography -- Relationships; ref. 20639] Raudal Alto, about 90 kilometers NE of mouth of Papunava River, Inriida River basin, Guainia Dept. Colombia. Holotype: NRM 16548. Paratypes: NRM 14687 (19). •Valid as Rivulus altivelis Huber 1992 -- (Lazara 2001:270 [ref. 25711], Costa in Reis et al. 2003:534 [ref. 27061], Hrbek et al. 2004:575 [ref. 27910], Costa 2006:157 [ref. 28875] in subgenus Owiyeye, Schindler & Valdesalici 2011:109 [ref. 31382], Vermeulen & Mejia-Vargas 2020:19 [ref. 37935], Vermeulen & Mejia-Vargas 2020:34 [ref. 37938]). •Valid as Laimosemion altivelis (Huber 1992) -- (Costa 2011:239 [ref. 31655], Costa & Lazzarotto 2014:372 [ref. 33247], DoNascimiento et al. 2017:101 [ref. 35633]). Current status: Valid as Laimosemion altivelis (Huber 1992). Rivulidae: Rivulinae. Distribution: South America: Orinoco River basin (Colombia). Habitat: freshwater.

altus, Cynolebias Costa [W. J. E. M.] 2001:370 [Ichthyological Exploration of Freshwaters v. 12 (no. 4); ref. 25719] 25 kilometers south of Ibotirama, rio São Francisco floodplains, about 12°30'S, 43°10'W, Bahia, Brazil. Holotype: MZUSP 62564. Paratypes: MZUSP 62565 (5); UFRJ 4785 (3), 4794 (1), 4798-99 (7, 8), 5131 (3, c&s), 5132 (3, c&s), UFRJ uncat. (8). Plus additonal material. •Valid as Cynolebias altus Costa 2001 -- (Costa in Reis et al. 2003:529 [ref. 27061], Costa 2009:146 [ref. 30511], Costa 2014:80 [ref. 33510], Loureiro et al. 2018:11 [ref. 36240], Silva et al. 2020:13 [ref. 37809]). Current status: Valid as Cynolebias altus Costa 2001. Rivulidae: Cynolebiinae. Distribution: South America: middle São Francisco River basin (Brazil). Habitat: freshwater.

amambaiensis, Melanorivulus Volcan [M. V.], Severo-Neto [F.] & Lanés [L. E. K.] 2018:272, Figs. 8-9 [Zoosystematics and Evolution v. 94 (no. 2); ref. 35895] First order stream of Rio Amambaí, margin of BR 487 highway, near of municipality of Naviraí, Mato Grosso do Sul state, Brazil, 22°57'11"S, 54°26'52"W, elevation 332 meters. Holotype: MCP 53150. Paratypes: MCP, ZUFMS. •Valid as Melanorivulus amambaiensis Volcan, Severo-Neto & Lanés 2018. Current status: Valid as Melanorivulus amambaiensis Volcan, Severo-Neto & Lanés 2018. Rivulidae: Rivulinae. Distribution: South America: Rio Amambaí drainage, Rio Paraná basin, Mato Grosso do Sul state, Brazil. Habitat: freshwater.

amanan, Rivulus Costa [W. J. E. M.] & Lazzarotto [H.] 2008:130, Figs. 1-2 [Ichthyological Exploration of Freshwaters v. 19 (no. 2); ref. 29870] Pools at the floodplains of Igarapé do Baré, near Cano do Lago da Beleza, Lago Amanã system, Reserva de Desenvolvimento, Japurá-Solimões drainage, Rio Amazonas basin, 2°17.280'S, 64°41.635'W, Município de Maraã, Estado do Amazonas, Brazil. Holotype: UFRJ 6571. Paratypes: MNRJ 31908 (4, c&s); UFRJ 6572 (9), 6573 (6). •Valid as Anablepsoides amanan (Costa & Lazzarotto 2008) -- (Costa 2011:243 [ref. 31655], Nielsen & Veiga 2021:10 [ref. 38269]). Current status: Valid as Anablepsoides amanan (Costa & Lazzarotto 2008). Rivulidae: Rivulinae. Distribution: South America: Japurá-Solimões drainage, Amazon River basin, Brazil. Habitat: freshwater.

amanapira, Rivulus Costa [W. J. E. M.] 2004:7, Figs. 4-5 [Zootaxa No. 465; ref. 27570] Pools near igarapé Palestina, Airport road, upper rio Negro drainage, rio Amazonas basin, São Gabriel da Cachoeira, Estado do Amazonas, Brazil, 0°09'19.2"S, 66°59'58.9"W, elevation 100 meters. Holotype: UFRJ 5929. Paratypes: MCP 34859 (2); UFRJ 5930 (11), 5931 (3 c&s). •Valid as Rivulus amanapira Costa 2004 -- (Costa 2004:11 [ref. 27656], Hrbek et al. 2004:575 [ref. 27910], Costa 2004:2 [ref. 27923], Costa 2006:157, 160 [ref. 28875] in subgenus Owiyeye, Schindler & Valdesalici 2011:109 [ref. 31382], Vermeulen et al. 2013:191 [ref. 32954], Vermeulen & Mejia-Vargas 2020:19 [ref. 37935], Vermeulen & Mejia-Vargas 2020:34 [ref. 37938]). •Valid as Laimosemion amanapira (Costa 2004) -- (Costa 2011:239 [ref. 31655], Costa & Bragança 2013:93 [ref. 32797], Costa & Lazzarotto 2014:372 [ref. 33247]). Current status: Valid as Laimosemion amanapira (Costa 2004). Rivulidae: Rivulinae. Distribution: Upper Negro River drainage, Amazon basin, northern Brazil. Habitat: freshwater.

amphoreus, Rivulus Huber [J. H.] 1979:68, Figs. 4-6 [Revue française d'Aquariologie Herpétologie v. 6 (no. 3); ref. 8826] Vicinity of Tafelberg, zone of high hills up to 1000 meters in elevation, 120 kilometers south-southwest of Paramaribo, Suriname. Holotype: MNHN 1979-0286. Paratypes: MNHN 1979-0287 (2). •Valid as Rivulus amphoreus Huber 1979 -- (Huber 1992:96 [ref. 20639], Lazara 2001:270 [ref. 25711], Costa in Reis et al. 2003:534 [ref. 27061], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys). •Valid as Anablepsoides amphoreus (Huber 1979) -- (Costa 2011:243 [ref. 31655], Valdesalici 2015:247 [ref. 34049]). Current status: Valid as Anablepsoides amphoreus (Huber 1979). Rivulidae: Rivulinae. Distribution: Atlantic River basins, Suriname. Habitat: freshwater.

anitae, Laimosemion Nielsen [D. T. B.], Hoetmer [J. W.] & Vandenkerkhove [E.] 2023:299 [Zootaxa 5323 (no. 2); ref. 40342] Stream tributary of Igarapé Japiim, a tributary of rio Moa, Rio Juruá drainage, Amazon basin, Mânchio Lima, Acre, Brazil, 7°34'15.5"S, 72°57'31.5"W. Holotype: ZUEC 17365. Paratypes: ZUEC 17366 (6), 17367 (4). Appeared first in an unavailable publication, ref. 39106, p. 38, Figs. 1-2. •Valid as Laimosemion anitae Nielsen, Hoetmer & Vandenkerkhove 2023. Current status: Valid as Laimosemion anitae Nielsen, Hoetmer & Vandenkerkhove 2023. Rivulidae: Rivulinae. Distribution: South America: Rio Juruá drainage, Amazon basin, Acre, Brazil. Habitat: freshwater.

antenori, Cynolebias Tulipano [J.] 1973:23 [Killie Notes, American Killifish Association v. 6 (no. 11); ref. 20289] Temporary pool, 2.5 kilometers north of Limoeiro do Norte, rio Jaguaribe floodplains, about 5°10'S, 38°05'W, Ceará, northeastern Brazil. Neotype: MZUSP 56256. Appeared first without distinguishing features in Myers 1952:139 [ref. 3125] as a nomen nudum; also appeared as a nomen nudum, Cynolebias 'antenori' in Langton 1972:18 [ref. 41085]. Neotype designated by Costa 2003:38 [ref. 26758]. See Huber 2006:22 [ref. 28935] for a different point of view. •Valid as Cynolebias antenori Tulipano 1973 -- (Costa 1995:57 [ref. 22097], Murphy & Collier 1997:797 [ref. 25585]). •Valid as Simpsonichthys antenori (Tulipano 1973) -- (Costa 1996:130 [ref. 25271], Costa 1998:75 [ref. 23792], Lazara 2001:295 [ref. 25711], Costa 2003:38 [ref. 26758], Costa in Reis et al. 2003:540 [ref. 27061], Costa 2006:26 [ref. 28771], Costa 2006:17 [ref. 28620], Costa 2007:96 [ref. 29445]). •Valid as Hypsolebias antenori (Tulipano 1973) -- (Costa 2011:222 [ref. 31654], Costa et al. 2012:73 [ref. 31845], Costa et al. 2013:1 [ref. 32952], Britzke et al. 2016:134 [ref. 34461], Loureiro et al. 2018:11 [ref. 36240], Abrantes et al. 2020:306 [ref. 37698], Abrantes et al. 2023:559 [ref. 40706]). Current status: Valid as Hypsolebias antenori (Tulipano 1973). Rivulidae: Cynolebiinae. Distribution: South America: Rio Jaguaribe floodplains, Rio Grande do Norte (Brazil). Habitat: freshwater.

apaii, Austrolebias Costa [W. J. E. M.], Laurino [P.], Recuero [R.] & Salvia [H.] in Costa 2006:108, Fig. 42 [Zootaxa No. 1213; ref. 28708] Carmelo, 34°00.31'S, 58°17.00'W, Colonia, Uruguay. Holotype: MUNH [MUNHINA] 3216. Paratypes: UFRJ 6226 (14), 6227 (6, c&s); MUNH 3217 (59); ZSM 33650 (102). Plus non-type material. Type catalog: Neumann 2011:276 [ref. 31652]. •Valid as Austrolebias apaii Costa, Laurino, Recuero & Salvia 2006 -- (Costa 2009:188 [ref. 30417], Koerber 2011:7 [ref. 31122], Koerber 2014:11 [ref. 33621], Litz & Koerber 2014:30 [ref. 33622], Mirande & Koerber 2015:51 [ref. 35117], Nión et al. 2016:42 [ref. 35565]). •Synonym of Austrolebias bellottii (Steindachner 1881) -- (Koerber et al. 2017:7 [ref. 35083], Volcan & Severo-Neto 2019:542 [ref. 36539], Mirande & Koerber 2020:2 [ref. 37594]). Current status: Synonym of Austrolebias bellottii (Steindachner 1881). Rivulidae: Cynolebiinae. Habitat: freshwater.

apiamici, Rivulus Costa [W. J. E. M.] 1989:527, Figs. 3-3a [Revista Brasileira de Zoologia v. 6 (no. 3); ref. 14319] Bataquaçu, close to the state border, Mato Grosso do Sul, Brazil. Holotype: MZUSP 39976. Paratypes: MZUSP 39977 (6), plus non-type material. •Doubtfully valid as Rivulus apiamici Costa 1989 -- (Huber 1992:99 [ref. 20639]). •Synonym of Rivulus pictus Costa 1989 -- (Costa 1995:212 [ref. 21883], Lazara 2001:283 [ref. 25711]). •Valid as Rivulus apiamici Costa 1989 -- (Costa in Reis et al. 2003:534 [ref. 27061], Costa 2005:71 [ref. 28192], Costa 2006:162 [ref. 28875] in subgenus Melanorivulus). •Valid as Melanorivulus apiamici (Costa 1989) -- (Costa 2011:241 [ref. 31655], Nielsen et al. 2016:84 [ref. 34407], Deprá et al. 2017:113 [ref. 35503], Volcan et al. 2018:275 [ref. 35895], Ywamoto et al. 2020:128 [ref. 37763]). Current status: Valid as Melanorivulus apiamici (Costa 1989). Rivulidae: Rivulinae. Distribution: Paraná river basin, Mato Grosso do Sul state, Brazil. Habitat: freshwater.

aplocheiloides, Trigonectes Huber [J. H.] 1995:17, Fig. 8 [Killi-Contact - Périodique bimestriel Spec. publ.; ref. 22880] 74 kilometers from Mariscal Estigarribia in the direction of Americo Picco, 21.30°S, 60.51°W, Paraguay. Holotype: MNHN 1994-1104. Paratypes: ANSP 169976-77 (3, 1), 169980 (1), 170416 (2), 170420 (1); MNHN 1994-1105 (1). Appeared first as above, then in Huber 1995 (Nov.):117, Figs. 13-14 [ref. 22204]. •Valid as Trigonectes aplocheiloides Huber 1995 -- (Costa 1998:78 [ref. 23792], Lazara 2001:309 [ref. 25711], Costa in Reis et al. 2003:543 [ref. 27061], López et al. 2003:70 [ref. 27366], Mirande & Koerber 2015:52 [ref. 35117], Calviño et al. 2016:11 [ref. 34699], Koerber et al. 2017:72 [ref. 35267], Drawert & Osinaga 2022:36 [ref. 40731], Drawert 2023:40 [ref. 40730]). Current status: Valid as Trigonectes aplocheiloides Huber 1995. Rivulidae: Rivulinae. Distribution: South America: Paraguay River basin (Argentina, Bolivia and Paraguay). Habitat: freshwater.

apurinan, Moema Costa [W. J. E. M.] 2004:3, Figs. 1-2 [Zootaxa No. 707; ref. 27924] Temporary forest pool, Rio Acre floodplains, Rio Purus drainage, Rio Amazonas basin, 9°35'12.2"S, 67°31'50.6"W, Porto Acre, Estado do Acre, Brazil, elevation 132 meters. Holotype: UFRJ 5980. Paratypes: UFRJ 5981 (9), 5982 (7, 3 c&s). •Valid as Moema apurinan Costa 2004 -- (Valdesalici 2016:71 [ref. 34174]). Current status: Valid as Moema apurinan Costa 2004. Rivulidae: Rivulinae. Distribution: Acre River floodplains, Purus River drainage, Amazon River basin, northwestern Brazil. Habitat: freshwater.

arachan, Austrolebias Loureiro [M.], Azpelicueta [M. de las M.] & García [G.] 2004:23, Figs. 1-2 [Revue Suisse de Zoologie v. 111 (no. 1); ref. 27658] Pond close to Route 7 and Arroyo Chuy, Laguna Merín basin, Depart. Cerro Largo, Uruguay, about 32°15'S, 54°00'W. Holotype: ZVC-P 4336. Paratypes: MHNG 2641.88 (6); ZVC-P 4314 (3), 4317 (8, 4 c&s), 4329 (4, c&s), 4331 (21, 3 c&s), 4332 (15), 4333 (19, 8 c&s), 4335 (6), 4528 (6, 2 c&s), 4574 (14, 2 c&s). Type catalog: Loureiro et al. 2016:414 [ref. 35150]. Previously known to aquarists as Austrolebias uruguayensis, a nomen nudum. •Valid as Austrolebias arachan Loureiro, Azpelicueta & García 2004 -- (Costa 2006:113 [ref. 28708], Costa 2009:188 [ref. 30417], Loureiro et al. 2011:340 [ref. 31392], Lanés et al. 2014:17 [ref. 33234], Volcan et al. 2014:171 [ref. 33543], Litz & Koerber 2014:30 [ref. 33622], Bertaco et al. 2016:423 [ref. 34561], Nión et al. 2016:42 [ref. 35565], Loureiro et al. 2018:11 [ref. 36240], Lanés et al. 2021:514 [ref. 38189], Volcan et al. 2021:104 [ref. 38292], Loureiro et al. 2023:167 [ref. 40506]). •Valid as Garcialebias arachan (Loureiro, Azpelicueta & García 2004) -- (Alonso et al. 2023:13 [ref. 40292], Koerber et al. 2023:10 [ref. 40355]). Current status: Valid as Garcialebias arachan (Loureiro, Azpelicueta & García 2004). Rivulidae: Cynolebiinae. Distribution: South America: along the border of Uruguay and Rio Grande do Sul (Brazil and Uruguay). Habitat: freshwater.

araucarianus, Austrolebias Costa [W. J. E. M.] 2014:98, Figs 1-2 [Ichthyological Exploration of Freshwaters v. 25 (no. 2); ref. 33514] Temporary swamp near road BR-476, Claro river floodplains, Iguaçu river drainage, Paraná river basin, 26°01'12"S, 50°39'08"E, southern Brazil, elevation 785 meters. Holotype: UFRJ 9797. Paratypes UFRJ 9798 (16), 9799 (6). •Valid as Austrolebias araucarianus Costa 2014 -- (Alonso et al. 2018:10 [ref. 35938], Loureiro et al. 2018:11 [ref. 36240], Reis et al. 2020:473 [ref. 38364], Lanés et al. 2021:513 [ref. 38189]). •Valid as Garcialebias araucarianus (Costa 2014) -- (Alonso et al. 2023:13 [ref. 40292]). Current status: Valid as Garcialebias araucarianus (Costa 2014). Rivulidae: Cynolebiinae. Distribution: South America: Claro Rive floodplains, upper Iguaçu River basin (southern Brazil). Habitat: freshwater.

aruana, Cynolebias Lazara [K. J.] 1991:147, Figs. 4-5 [Journal of the American Killifish Association v. 23 (no. 5); ref. 20508] Temporary pool, Aruana, Goiás State, Brazil. Holotype: MZUSP 38794. Paratypes: AMNH 59191 (18), 59288 (34, 18 c&s); MHNM 3102:1-10 (10); MZUSP 38795-804 (10). •Valid as Plesiolebias aruana (Lazara 1991) -- (Costa 1995:30 [ref. 22097], Costa 1995:73 [ref. 21612], Costa 1998:325 [ref. 23324], Costa 1998:81 [ref. 23792], Costa & Le Bail 1999:1028 [ref. 24187], Lazara 2001:257 [ref. 25711], Costa et al. 2003:144 [ref. 26946], Costa in Reis et al. 2003:533 [ref. 27061]). Current status: Valid as Plesiolebias aruana (Lazara 1991). Rivulidae: Rivulinae. Distribution: Araguaia-Tocantins River basin, Brazil. Habitat: freshwater.

ashleyae, Papiliolebias Nielsen [D. T. B.] & Brousseau [R.] 2014:54, Figs. 1-2 [aqua, International Journal of Ichthyology v. 20 (no. 1); ref. 33146] Departamento Santa Cruz, north of San José dos Chiquitos, Rio San Pablo, upper Rio Mamoré basin, 17°18’22.7"S, 60°38’36.0"W, Bolivia, elevation 313 meters. Holotype: MNKP-11203. Paratypes: MNKP-11204 (5), ZUEC 7297 (2). •Valid as Papiliolebias ashleyae Nielsen & Brousseau 2014 -- (Valdesalici & Brousseau 2014:118 [ref. 33449], Valdesalici et al. 2016:162 [ref. 34860], Drawert 2023:24 [ref. 40730]). Current status: Valid as Papiliolebias ashleyae Nielsen & Brousseau 2014. Rivulidae: Rivulinae. Distribution: South America: upper Rio Mamoré basin (Bolivia). Habitat: freshwater.

atlanticus, Melanorivulus Costa [W. J. E. M.], Bragança [P. H. N.] & Ottoni [F. P.] 2015:32, Fig. 1 [Vertebrate Zoology v. 65 (no. 1); ref. 33784] Estado de Sergipe, Município de Pirambu, swamp in the coastal Restinga, between Lagoa Grande and Pau Seco, about 3.5 km from the sea coast, Brazil, 10°37’10"S, 36°43’50"W. Holotype: UFRJ 10243. Paratypes: UFRJ. •Valid as Melanorivulus atlanticus Costa, Bragança & Ottoni 2015 -- (Costa et al. 2016:270 [ref. 35405], Costa 2017:64 [ref. 35046]). Current status: Valid as Melanorivulus atlanticus Costa, Bragança & Ottoni 2015. Rivulidae: Rivulinae. Distribution: Brazil. Habitat: freshwater.

atratus, Rivulus Garman [S.] 1895:140 [Memoirs of the Museum of Comparative Zoology v. 19 (pt 1); ref. 1538] Rio Jutahy, Amazonas, Brazil. Lectotype: MCZ 6318. Paralectotypes: MCZ 6268 (2), MCZ 98675 [ex MCZ 6318] (2). Lectotype established in Huber 1992:102 [ref. 20639]. •Probably a synonym of Rivulus ornatus Garman 1898 -- (Hrbek et al. 2004:569 [ref. 27910]). •Valid as Rivulus atratus Garman 1895 -- (Ortega & Vari 1986:19 [ref. 9708], Huber 1992:102 [ref. 20639], Lazara 2001:270 [ref. 25711], Costa in Reis et al. 2003:534 [ref. 27061], Costa 2003:176 [ref. 27578], Costa 2004:4 [ref. 27570], Costa 2004:11 [ref. 27656], Costa 2004:2 [ref. 27923], Costa 2006:147, 150 [ref. 28875] in subgenus Anablepsoides, Costa & Lazzarotto 2008:129 [ref. 29870], Schindler & Valdesalici 2011:113 [ref. 31382]). •Valid as Anablepsoides atratus (Garman 1895) -- (Costa 2011:243 [ref. 31655], DoNascimiento et al. 2017:101 [ref. 35633], Meza-Vargas et al. 2021:27 [ref. 39298]). Current status: Valid as Anablepsoides atratus (Garman 1895). Rivulidae: Rivulinae. Distribution: South America: Amazon River basin (Brazil, Colombia and Peru). Habitat: freshwater.

attenuatus, Cynolebias Costa [W. J. E. M.] 2001:375, Figs. 28-29 [Ichthyological Exploration of Freshwaters v. 12 (no. 4); ref. 25719] Temporary pool, 12 kilometers west of Bom Jesus da Lapa, about 13°15'S, 43°40'W, Bahia, Brazil. Holotype: MZUSP 62566. Paratypes: MZUSP 62567 (1); UFRJ 4778 (6), 4779 (2 c&s), 5143 (8, c&s). Plus additional non-type material. •Valid as Cynolebias attenuatus Costa 2001 -- (Costa in Reis et al. 2003:529 [ref. 27061], Costa 2009:146 [ref. 30511], Costa 2014:80 [ref. 33510], Silva et al. 2020:13 [ref. 37809]). Current status: Valid as Cynolebias attenuatus Costa 2001. Rivulidae: Cynolebiinae. Distribution: South America: middle São Francisco River basin (Brazil). Habitat: freshwater.

aurata, Rivulus urophthalmus var. Schreitmüller [W.] 1919:161, Fig. [Wochenschrift für Aquarien- und Terrarienkunde v. 16 (no. 11); ref. 31537] Maharankao [= Maranhão], Brazil/Peru or Cayenne, French Guyana? No types known. Referred to as a xanthic form in the original, an artificially bred variety. Also appeared in Schreitmüller 1928:88, Fig. 56 [ref. 20640] and 1929:57 [ref. 23865]. A species-group name based on a bred aquaristic variety (selected or hybrid ?) is not an available species name. •Incorrectly valid as Rivulus auratus Schreitmüller 1919 -- (Costa in Reis et al. 2003:534 [ref. 27061]). •In the synonymy of Rivulus urophthalmus Günther 1866 -- (Huber 1992:106 [ref. 20639], Lazara 2001:285 [ref. 25711], Costa 2006:139 [ref. 28875]). •In the synonymy of Anablepsoides urophthalmus (Günther 1866). Current status: Synonym of Anablepsoides urophthalmus (Günther 1866). Rivulidae: Rivulinae.

auratus, Simpsonichthys Costa [W. J. E. M.] & Nielsen [D. T. B.] 2000:8, Fig. 1 [Ichthyological Exploration of Freshwaters v. 11 (no. 1); ref. 24442] Temporary pool close to rio Taboca, a tributary of rio Paracatú, rio São Francisco basin, Lagoa Grande, Minas Gerais State, Brazil. Holotype: MZUSP 52912. Paratypes: MZUSP 52913 (3); UFRJ 4666 (3), 4667 (10, c&s), 4668 (10); UMMZ 234240 (2); plus non-type material. •Valid as Simpsonichthys auratus Costa & Nielsen 2000 -- (Lazara 2001:295 [ref. 25711], Costa in Reis et al. 2003:540 [ref. 27061], Costa 2005:63 [ref. 28575], Costa 2006:17 [ref. 28620], Costa 2007:79 [ref. 29445]). •Valid as Hypsolebias auratus (Costa & Nielsen 2000) -- (based on generic placement in Costa 2011 [ref. 31654]). Current status: Valid as Hypsolebias auratus (Costa & Nielsen 2000). Rivulidae: Cynolebiinae. Distribution: Taboca River floodplains, Paracatu River drainage, middle São Francisco River basin, Minas Gerais State, Brazil. Habitat: freshwater.

aureoguttatus, Cynolebias Myers [G. S.] 1952:131, unnum. fig. on p. 134 [Aquarium Journal v. 23 (no. 7); ref. 3125] The name Cynolebias paranaguensis, mentioned in the same paragraph, is an obvious mistake for C. aureoguttatus; it has never been made available. The name aureoguttatus appears in the caption to the specimens figured on p. 134 but it is not available because no distinguishing features are presented (names published after 1930, Art. 13). Validly published by Da Cruz 1974 (see Costa 1995:94 [ref. 22097]). •In the synonymy of Leptolebias aureoguttatus (Da Cruz 1974) -- (Costa in Reis et al. 2003:530 [ref. 27061], Costa 2008:149 [ref. 29596]). •In the synonymy of Leptopanchax aureoguttatus (Da Cruz 1974). Nomen Nudum. Current status: Synonym of Leptopanchax aureoguttatus (Da Cruz 1974). Rivulidae: Cynolebiinae.

aureoguttatus, Cynolebias Da Cruz [C. A. G.] 1974:20, Fig. 1 [Arquivos da Universidade Federal Rural do Rio de Janeiro v. 2 (no. 4); ref. 22101] Ditch parallel to road between Paranaguá and Matinhos, near kilometer 11, Paraná, Brazil, ca. 25°30'S, 48°25'W, elevation 5 meters. Lectotype: MNRJ 28924. Paralectotypes: MNRJ 19495 (2). Lectotype selected by Costa 2008:149 [ref. 29596]. •Valid as Leptolebias aureoguttatus (Da Cruz 1974) -- (Costa 1995:94 [ref. 22097], Costa 1998:73 [ref. 23792], Lazara 2001:193 [ref. 25711], Costa 2002:383 [ref. 26544], Costa in Reis et al. 2003:530 [ref. 27061], Costa 2008:149 [ref. 29596], Ferrer et al. 2014:847 [ref. 33589]). •Valid as Leptopanchax aureoguttatus (Da Cruz 1974) -- (Costa 2016:128 [ref. 34776], Loureiro et al. 2018:11 [ref. 36240], Costa 2019:82 [ref. 36869], Reis et al. 2020:473 [ref. 38364]). Current status: Valid as Leptopanchax aureoguttatus (Da Cruz 1974). Rivulidae: Cynolebiinae. Distribution: South America: Atlantic coastal plain basins, southeastern Mata Atlantica (Brazil). Habitat: freshwater.

aureomaculatus, Neofundulus Costa [W. J. E. M.] 2015:20, Fig. 4 [Vertebrate Zoology v. 65 (no. 1); ref. 33783] Estado de Mato Grosso do Sul, Município de Aquidauana: temporary pool about 15 km NW of the town of Aquidauana, road MS-170, Aquidauana river floodplains, Paraguay river basin, 20°19’14"S, 55°50’36"W, altitude about 135 meters. Holotype: UFRJ 10087. Paratypes: UFRJ. •Valid as Neofundulus aureomaculatus Costa 2015. Current status: Valid as Neofundulus aureomaculatus Costa 2015. Rivulidae: Rivulinae. Distribution: Temporary pool at 15 km NW of the town of Aquidauana, Brazil. Habitat: freshwater.

auriferus, Prorivulus Costa [W. J. E. M.], Lima [S. M. Q.] & Suzart [R. dos R.] in Costa 2004:3, Figs. 1-2 [Zootaxa No. 642; ref. 27874] Valença, coastal stream, (24L 0503477 UTM 8505050), Estado da Bahia, Brazil. Holotype: UFRJ 5932. Paratypes: UFRJ 5933 (4), 5934 (3, c&s). •Valid as Prorivulus auriferus Costa, Lima & Suzart 2004 -- (Silva et al. 2020:15 [ref. 37809], Vieira-Guimarães et al. 2024:55 [ref. 41258]). Current status: Valid as Prorivulus auriferus Costa, Lima & Suzart 2004. Rivulidae: Rivulinae. Distribution: South America: Bahia State (Brazil). Habitat: freshwater.

ayoreode, Austrolebias Drawert [H. A.] & Ergueta [C.] 2024:13, Figs. 5-7 [Neotropical Ichthyology v. 22 (no. 2): e240001; ref. 41211] Temporary pool on side of dirt road between San Jorge and Ponderosa ranches ca. 10 km west of San Jorge, San Miguel watershed, upper Paraguay River drainage, La Plata basin, Santa Cruz, Bolivia, 19°08'46"S, 59°55'44"W. Holotype: MNKP 16612. Paratypes: MNKP 16587 (23), 16590 (3). Plus additional non-type material. •Valid as Austrolebias ayoreode Drawert & Ergueta 2024. Current status: Valid as Austrolebias ayoreode Drawert & Ergueta 2024. Rivulidae: Cynolebiinae. Distribution: South America: temporary pools in the San Miguel River drainage, upper Paraguay River basin, La Plata system, Cordillera Province, Santa Cruz Department, Bolivia. Habitat: freshwater.

azurescens, Rivulus Vermeulen [F. B. M.] 2013:47, Figs. 2-3 [Killi-Data Series 2013; ref. 33089] Antioquia, little mountain creek opposite to the entrance of Rancho San Silvestre, 4 km before Doradal, on the left side of the road 60, from Medellin to Puerto Triunfo, Colombia, 05°54'93"N, 7°46'85"W, elevation 353 meters. Holotype (unique): IAVHP 11255. Paratype: RMNH.PISC 36364 (1). Type catalog: DoNascimiento et al. 2016:427 [ref. 34787]. Genus tentative. •Valid as Rivulus azurescens Vermeulen 2013 -- (DoNascimiento et al. 2017:101 [ref. 35633], Gomes 2023:17 [ref. 40174]). •Valid as Cynodonichthys azurescens (Vermeulen 2013). Current status: Valid as Cynodonichthys azurescens (Vermeulen 2013). Rivulidae: Rivulinae. Distribution: South America: Antioquia, Colombia. Habitat: freshwater.

bagual, Austrolebias Volcan [M. V.], Lanés [L. E. K.] & Gonçalves [Â. C.] 2014:163, Figs. 1-3 [aqua, International Journal of Ichthyology v. 20 (no. 4); ref. 33543] Rio Grande do Sul State, Laguna dos Patos system, Rio Camaquã basin, temporary pond in the floodplains of Arroio Abranjo, close to BR-471 highway (30°51’12"S, 52°34’16"W), southern Brazil. Holotype: MCP 48240. Paratypes: MCP 48241 (10). •Valid as Austrolebias bagual Volcan, Lanés & Gonçalves 2014 -- (Bertaco et al. 2016:423 [ref. 34561], Loureiro et al. 2018:11 [ref. 36240], Volcan et al. 2021:104 [ref. 38292]). •Valid as Garcialebias bagual (Volcan, Lanés & Gonçalves 2014) -- (Alonso et al. 2023:13 [ref. 40292]). Current status: Valid as Garcialebias bagual (Volcan, Lanés & Gonçalves 2014). Rivulidae: Cynolebiinae. Distribution: South America: temporary pools in the floodplains of Arroio Abranjo, Rio Camaquã basin, Laguna dos Patos system, southeastern Brazil. Habitat: freshwater.

bahianus, Rivulus Huber [J. H.] 1990:14, Fig. 1 [Revue française d'Aquariologie Herpétologie v. 17 (no. 1); ref. 18931] Near Itapoa, vicinity of Salvador do Bahia International Airport, Bahia State, Brazil. Holotype: MNHN 1988-1172. Paratypes: MNHN 1988-1173 and 1174 (2, 19). •Valid as Rivulus bahianus Huber 1990 -- (Huber 1992:108 [ref. 20639], Lazara 2001:270 [ref. 25711], Costa in Reis et al. 2003:534 [ref. 27061], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys, Costa 2008:298 [ref. 30084]). •Valid as Anablepsoides bahianus (Huber 1999) -- (Costa 2011:243 [ref. 31655], Nielsen 2016:166 [ref. 34861], Silva et al. 2020:13 [ref. 37809], Vieira-Guimarães et al. 2024:54 [ref. 41258]). Current status: Valid as Anablepsoides bahianus (Huber 1990). Rivulidae: Rivulinae. Distribution: South America: Atlantic coastal river basins (Brazil). Habitat: freshwater.

balzanii, Haplochilus Perugia [A.] 1891:653 [53] [Annali del Museo Civico di Storia Naturale di Genova (Serie 2) v. 10; ref. 3431] Cáceres (formerly Villa María), Río Paraguay, Mato Grosso, Brazil. Syntypes: MSNG 9243 (orig. 6, now 5), NMW 81378 (2). Type catalog: Tortonese 1963:313 [ref. 10351]. On p. 53 of separate. •Valid as Trigonectes balzanii (Perugia 1891) -- (Costa 1990:140 [ref. 14542], Huber 1995:18 [ref. 22880], Costa 1998:78 [ref. 23792], Britski et al. 1999:140 [ref. 24147], Lazara 2001:309 [ref. 25711], Costa in Reis et al. 2003:543 [ref. 27061], López et al. 2003:71 [ref. 27366], Menni 2004:86 [ref. 28131], Sarmiento et al. 2014:187 [ref. 35004], Mirande & Koerber 2015:52 [ref. 35117], Calviño et al. 2016:11 [ref. 34699], Koerber 2016:142 [ref. 35012], Koerber et al. 2017:72 [ref. 35267], Drawert 2023:41 [ref. 40730]). Current status: Valid as Trigonectes balzanii (Perugia 1891). Rivulidae: Rivulinae. Distribution: South America: Paraguay River basin (Argentina, Brazil, Bolivia and Paraguay). Habitat: freshwater.

bellidoi, Spectrolebias Nielsen [D. T. B.] & Pillet [D.] 2015:181, Figs. 1-2 [aqua, International Journal of Ichthyology v. 21 (no. 4); ref. 34009] Departamento de Santa Cruz de La Sierra, temporary pool at Río Grande basin (trib. Río Mamoré basin), Bolivia, 18°39'26.2"S, 62°58'0.2"W, altitude 366 meters. Holotype: ZUEC 10794. Paratypes: ZUEC. •Valid as Spectrolebias bellidoi Nielsen & Pillet 2015 -- (Drawert 2023:11 [ref. 40730]). Current status: Valid as Spectrolebias bellidoi Nielsen & Pillet 2015. Rivulidae: Cynolebiinae. Distribution: South America: upper Río Grande, Río Mamoré basin, Amazon basin (Bolivia). Habitat: freshwater.

bellottii, Cynolebias Steindachner [F.] 1881:98 [Anzeiger der Akademie der Wissenschaften in Wien, Mathematisch-Naturwissenschaftliche Klasse v. 18 (no. 11) (for 5 May 1881); ref. 20484] La Plata, Argentina. Holotype (unique): NMW 75105. Species illustrated and described in more detail in Steindachner 1881:9, Pl. 5 (figs. 2-2a) [ref. 14299]. Spelled belotti by Ahl 1924 [ref. 15434]. •Valid as Cynolebias bellottii Steindachner 1881 -- (Costa 1995:71 [ref. 22097], Fuller et al. 1999:291 [ref. 25838]). •Valid as Austrolebias bellottii (Steindachner 1881) -- (Costa 1998:75 [ref. 23792], Lazara 2001:59 [ref. 25711], Costa 2002:917 [ref. 26505], Calviño 2003:10 [ref. 26595], Costa in Reis et al. 2003:527 [ref. 27061], López et al. 2003:69 [ref. 27366], Loureiro et al. 2004:27 [ref. 27658], Menni 2004:86 [ref. 28131] as bellotti, Calviño 2005:15 [ref. 28325], Calviño 2006:183 [ref. 28679], Costa 2006:104 [ref. 28708], Nielsen & Pillet 2015:172 [ref. 34011], Mirande & Koerber 2015:51 [ref. 35117], Alonso et al. 2016:5 [ref. 34643], Calviño et al. 2016:8 [ref. 34699], Nión et al. 2016:42 [ref. 35565], Koerber et al. 2017:7 [ref. 35083], Koerber et al. 2017:8 [ref. 35632], Loureiro et al. 2018:11 [ref. 36240], Serra & Loureiro 2018:553 [ref. 36329], Koerber et al. 2019:9 [ref. 36736], Volcan & Severo-Neto 2019:550 [ref. 36539], Koerber et al. 2020:9 [ref. 37480], Koerber et al. 2021:9 [ref. 38894], Alonso et al. 2023:10 [ref. 40292], Koerber et al. 2023:10 [ref. 40355], Loureiro et al. 2023:168 [ref. 40506]). Current status: Valid as Austrolebias bellottii (Steindachner 1881). Rivulidae: Cynolebiinae. Distribution: South America: lower de La Plata River basin and adjacent coastal plains to south (Uruguay and Argentina). Habitat: freshwater.

bellus, Stenolebias Costa [W. J. E. M.] 1995:71, Figs. 11-12 [Revue française d'Aquariologie Herpétologie v. 21 (no. 3/4) [for 1994]; ref. 21612] Temporary floodplains of Rio Miranda, about 5 kilometers south of Miranda, 20°17'S, 56°17'W, Estado de Mato Grosso de Sul, Brazil. Holotype: MZUSP 42310. Paratypes: MZUSP 42311 (1); UFRJ 385 (3, c&s), 386 (1, c&s). Also described as new in Costa 1995:26 [ref. 22097] as Plesiolebias bellus. •Valid as Stenolebias bellus Costa 1995 -- (Costa 1998:81 [ref. 23792], Costa & Le Bail 1999:1028 [ref. 24187], Lazara 2001:303 [ref. 25711], Costa in Reis et al. 2003:542 [ref. 27061]). Current status: Valid as Stenolebias bellus Costa 1995. Rivulidae: Rivulinae. Distribution: Paraguay River basin, Brazil. Habitat: freshwater.

beltramonorum, Moema Valdesalici [S.] 2023:595, Figs. 1-4 [Zootaxa 5383 (no. 4); ref. 40677] Swamp near the arroyo Crespo, Río San Martin, Iténez/Guaporé River basin, Bella Vista Municipality, Beni Department, Bolivia, 13°14'57.0"S, 63°41'46.1"W. Holotype: MSNG 62480. Paratypes: MSNG 62481 (2 + 2). •Valid as Moema beltramonorum Valdesalici 2023 -- (Drawert 2023:29 [ref. 40730]). Current status: Valid as Moema beltramonorum Valdesalici 2023. Rivulidae: Rivulinae. Distribution: South America: Río San Martin drainage, Río Iténez basin, Beni Department (Bolivia). Habitat: freshwater.

beniensis, Rivulus beniensis Myers [G. S.] 1927:133 [Bulletin of the Museum of Comparative Zoology v. 68 (no. 3); ref. 3096] Ivon, Río Beni, Bolivia. Lectotype: USNM 120432 [ex USNM 86766]. Paralectotypes: CAS 76353 [ex IU 17259] (?1), 76351 [ex IU 17258] (36); MCZ 31580 (8, now 6); UMMZ 66358 (11); USNM 120432 [ex MCZ 31580] (now 1), 86766 (5), 268121 (1), 167745 (5). Lectotype selected by Fels & Huber 1985:35 [ref. 8162] as USNM 86776 (26.4 mm). •Valid as Rivulus beniensis Myers 1927, subspecies beniensis Myers 1927 -- (Lazara 2001:270 [ref. 25711]). •Valid as Rivulus beniensis Myers 1927 -- (Fels & Huber 1985:33 [ref. 8162], Huber 1992:111 [ref. 20639], Costa in Reis et al. 2003:534 [ref. 27061], Costa 2006:150 [ref. 28875] in subgenus Benirivulus). •Valid as Anablepsoides beniensis (Myers 1927) -- (Costa 2011:243 [ref. 31655], Costa et al. 2013:292 [ref. 33108], Sarmiento et al. 2014:187 [ref. 35004], Valdesalici & Gil 2017:17 [ref. 35110], Careaga et al. 2020:77 [ref. 37774], Drawert 2023:19 [ref. 40730]). Current status: Valid as Anablepsoides beniensis (Myers 1927). Rivulidae: Rivulinae. Distribution: South America: Madeira River basin (Bolivia and Brazil). Habitat: freshwater.

berovidesi, Rivulus Rodriguez-Silva [R.] 2015:290, Figs. 2-6 [Zootaxa 3949 (no. 2); ref. 33779] Sierra de Cajalbana, Pinar del Rio Province, Cuba, 22°46'31.7"N, 83°26'31.7"W. Holotype: CZACC-9.83. Paratypes: CZACC, MFP, MNHN, MCZ. Type catalog: Faloh-Gandarilla et al. 2016:7 [ref. 35177]. •Valid as Rivulus berovidesi Rodriguez-Silva 2015 -- (Faloh-Gandarilla et al. 2016:7 [ref. 35177]). Current status: Valid as Rivulus berovidesi Rodriguez Silva 2015. Rivulidae: Rivulinae. Distribution: Cuba. Habitat: freshwater.

beucheyi, Moema Valdesalici [S.], Nielsen [D. T. B.] & Pillet [D.] 2015:129, Figs. 1-3 [aqua, International Journal of Ichthyology v. 21 (no. 3); ref. 33902] Seasonal pool, Río San Miguel drainage, Río Madeira basin, el Beni Department, Marban Province, Bolivian Amazon, 15°05'31.3"S, 63°57'24.9"W. Holotype: MSNG 58041. Paratypes: MSNG 58042 (5). •Valid as Moema beucheyi Valdesalici, Nielsen & Pillet 2015 -- (Valdesalici 2016:66 [ref. 34174], Drawert 2022:13 [ref. 39805], Drawert 2023:29 [ref. 40730]). Current status: Valid as Moema beucheyi Valdesalici, Nielsen & Pillet 2015. Rivulidae: Rivulinae. Distribution: South America: Iténez/Guaporé River drainage, Río Madeira basin (Bolivia). Habitat: freshwater.

bibosi, Anablepsoides Valdesalici [S.] & Gil [J. R. G.] 2019:150, Figs. 1-2 [aqua, International Journal of Ichthyology v. 25 (no. 4); ref. 37074] Arroyo Bibosi, near Villa Tunari, Río Chapare drainage, Rio Mamoré basin, Provincia Tiraque, Departamento Cochabamba, Bolivia, 16°59'07.6"S, 65°24'23.2"W. Holotype: MSNG 61243. Paratypes: MSNG 61244 (2). •Valid as Anablepsoides bibosi Valdesalici & Gil 2019 -- (Drawert 2023:21 [ref. 40730]). Current status: Valid as Anablepsoides bibosi Valdesalici & Gil 2019. Rivulidae: Rivulinae. Distribution: South America: Río Chapare drainage, upper Amazon basin (central Bolivia). Habitat: freshwater.

birkhahni, Rivulus Berkenkamp [H. O.] & Etzel [V.] 1992:102, Figs. [Deutsche Killifisch Gemeinschaft Journal v. 24 (no. 7); ref. 20601] Near Chiriqui Grande, Province Bocas del Toro, Panama, Caribbean side, 8°90'N, 82°10'W. Holotype: SMF 18436. Paratypes: SMF 18437 (4). •Valid as Rivulus birkhahni Berkenkamp & Etzel 1992 -- (Berkenkamp & Etzel 1993:22 [ref. 20600], Berkenkamp & Etzel 1999:64 [ref. 23985], Lazara 2001:271 [ref. 25711], Costa in Reis et al. 2003:534 [ref. 27061] Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys). •Valid as Cynodonichthys birkhahni (Berkenkamp & Etzel 1992) -- (Costa 2011:242 [ref. 31655]). Current status: Valid as Cynodonichthys birkhahni (Berkenkamp & Etzel 1992). Rivulidae: Rivulinae. Distribution: Caribbean river basins, Panama. Habitat: freshwater.

bitteri, Plesiolebias Costa [W. J. E. M.] 1989:195, Fig. 1 [Comunicações do Museu de Ciências da PUCRS, Série Zoologia v. 2 (no. 10); ref. 14436] 64 kilometers north of Mariscal Estigarribia, 21°03'S, 60°30'W, Nueva Asunción, Paraguay. Holotype: MNRJ 11554. Paratypes: MCP 12794 (2), MNRJ 11555 (2). •Valid as Plesiolebias bitteri Costa 1989 -- (Costa 1998:318 [ref. 23324]). •Valid as Cynolebias ("Plesiolebias") bitteri Costa 1989 -- (Huber 1995:12 [ref. 22880]). •Valid as Papiliolebias bitteri (Costa 1989) -- (Costa 1998:81 [ref. 23792], Lazara 2001:249 [ref. 25711], Costa in Reis et al. 2003:532 [ref. 27061], López et al. 2003:70 [ref. 27366], Menni 2004:86 [ref. 28131], Azpelicueta et al. 2009:313 [ref. 30672], Nielsen & Brousseau 2014:58 [ref. 33146], Valdesalici & Brousseau 2014:118 [ref. 33449], Sarmiento et al. 2014:187 [ref. 35004], Mirande & Koerber 2015:52 [ref. 35117], Calviño et al. 2016:10 [ref. 34699], Valdesalici et al. 2016:162 [ref. 34860], Koerber et al. 2017:7 [ref. 35083], Koerber et al. 2017:72 [ref. 35267], Koerber et al. 2017:8 [ref. 35632], Loureiro et al. 2018:11 [ref. 36240], Koerber et al. 2019:9 [ref. 36736], Drawert 2023:25 [ref. 40730]). Current status: Valid as Papiliolebias bitteri (Costa 1989). Rivulidae: Rivulinae. Distribution: South America: Paraguay River basin (Argentina, Bolivia and Paraguay). Habitat: freshwater.

boehlkei, Rivulus Huber [J. H.] & Fels [J. F.] 1985:316, Fig. 1 [Cybium v. 9 (no. 3); ref. 8153] Temporary creek, affluent of Río La Miel, Río Magdalena basin, Caldas Province, central Colombia. Holotype: ANSP 139467. Paratypes: ANSP 139467 (4). •Valid as Rivulus boehlkei Huber & Fels 1985 -- (Huber 1992:115 [ref. 20639], Lazara 2001:271 [ref. 25711], Costa in Reis et al. 2003:534 [ref. 27061], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys). •Valid as Cynodonichthys boehlkei (Huber & Fels 1985) -- (Costa 2011:242 [ref. 31655], DoNascimiento et al. 2017:101 [ref. 35633]). Current status: Valid as Cynodonichthys boehlkei (Huber & Fels 1985). Rivulidae: Rivulinae. Distribution: Magdalena River basin, Colombia. Habitat: freshwater.

boitonei, Simpsonichthys Carvalho [A. L. de] 1959:5, Figs. [Boletim do Museu Nacional do Rio de Janeiro, Zoologia, Nova Série No. 201; ref. 736] Temporary pool, central high flat land of Goiás State [now Distrito Federal], about 15°45'S, 48°00'W, Brazil, elevation 1100 meters. Holotype: MNRJ 9012. Paratypes: MNRJ 9013 (1), 9014-17 (4), 9018 (1, cleared & dissected). •Valid as Cynolebias boitonei (Carvalho 1959) -- (Shibatta & Garavello 1992:182 [ref. 21420], Costa 1995:60 [ref. 22097]). •Valid as Simpsonichthys boitonei Carvalho 1959 -- (Costa et al. 1996:17 [ref. 22219], Costa & Brasil 1996:95 [ref. 22917], Costa 1996:130 [ref. 25271], Costa 1998:75 [ref. 23792], Lazara 2001:295 [ref. 25711], Costa et al. 2003:140 [ref. 26946], Costa in Reis et al. 2003:540 [ref. 27061], Costa 2006:17 [ref. 28620], Costa & Brasil 2006:223 [ref. 28843], Costa & Brasil 2007:60 [ref. 29215], Costa 2007:200 [ref. 29338], Costa 2007:36 [ref. 29445], Costa 2012:314 [ref. 31750], Nielsen et al. 2017:166 [ref. 35304]). Current status: Valid as Simpsonichthys boitonei Carvalho 1959. Rivulidae: Cynolebiinae. Distribution: Upper São Bartolomeu River drainage, upper Paraná River, central Brazil. Habitat: freshwater.

bokermanni, Cynolebias Carvalho [A. L. de] & Da Cruz [C. A. G.] 1987:12, Figs. 1-3 [Arquivos da Universidade Federal Rural do Rio de Janeiro v. 8 (no. 1-2) [1985]; ref. 9127] Swamp near Ilhéus, Estado da Bahia, Brazil [about 14°50'S, 39°15W, elev about 40 m]. Holotype: MNRJ 11.167. Paratypes: CAGC 119.1 (1), MNRJ 11.168 (2). •Valid as Cynolebias bokermanni Carvalho & Da Cruz 1987 -- (Costa 1995:46 [ref. 22097]). •Valid as Simpsonichthys bokermanni (Carvalho & Da Cruz 1987) -- (Costa 1996:130 [ref. 25271], Costa 1998:75 [ref. 23792], Lazara 2001:296 [ref. 25711], Costa in Reis et al. 2003:540 [ref. 27061], Costa 2004:6 [ref. 27569], Costa 2007:18 [ref. 29445] with author as Cruz, Costa & Lima 2010:205 [ref. 31041] in subgenus Ophthalmolebias). •Valid as Ophthalmolebias bokermanni (Carvalho & Da Cruz 1987) -- (Silva et al. 2020:15 [ref. 37809], Vieira-Guimarães et al. 2024:55 [ref. 41258]). Current status: Valid as Ophthalmolebias bokermanni (Carvalho & Da Cruz 1987). Rivulidae: Cynolebiinae. Distribution: South America: floodplains of Cachoeira River basin, Bahia State (Brazil). Habitat: freshwater.

bokermanni, Pterolebias Travassos [H.] 1955:35, Figs. 1-2 [Revista Brasileira de Biologia v. 15 (no. 1); ref. 12534] Guajará-Mirim River floodplains, Madeira River drainage, Amazon basin, Guaporé [now Rondônia], Brazil. Holotype: MNRJ 8672. Paratypes: MNRJ 8697 (1), 8698 (1, allotype), 8699 (1). •Valid as Pterolebias bokermanni Travassos 1955 -- (Lazara 2001:263 [ref. 25711], Costa in Reis et al. 2003:533 [ref. 27061], Schindler 2004:71 [ref. 28034]). •Synonym of Pterolebias longipinnis Garman 1895 -- (Costa 2005:13 [ref. 28393], Mirande & Koerber 2015:52 [ref. 35117], Koerber et al. 2017:71 [ref. 35267]). Current status: Synonym of Pterolebias longipinnis Garman 1895. Rivulidae: Rivulinae. Habitat: freshwater.

bolivianus, Rivulus Seegers [L.] 1988:172, Figs. 1, 3 [Bonner Zoologische Beiträge v. 39 (nos 2-3); ref. 16282] Suarez lake, about 4 kilometers southeast of Trinidad, at Río Mamore mouth, 14°55'S, 64°55'W, Bolivia. Holotype: ZFMK 14602. Paratypes: ZFMK 14603-09 (7). Type catalog: Herder et al. 2010:125 [ref. 31087]. •Questionably valid as Rivulus bolivianus Seegers 1988 -- (Huber 1992:118 [ref. 20639]). •Valid as Rivulus bolivianus Seegers 1988 -- (Lazara 2001:271 [ref. 25711]). •Synonym of Rivulus beniensis Myers 1927 -- (Costa in Reis et al. 2003:534 [ref. 27061], Costa 2006:150 [ref. 28875]). •Synonym of Anablepsoides beniensis (Myers 1927). Current status: Synonym of Anablepsoides beniensis (Myers 1927). Rivulidae: Rivulinae. Habitat: freshwater.

bonairensis, Rivulus marmoratus Hoedeman [J. J.] 1958:117 [Studies on the Fauna of Curacao and other Caribbean Islands v. 8; ref. 12070] Pos di Pepe, Bonaire, Netherland Antilles. Holotype: ZMA 100436. Paratypes: BMNH 1958.9.2.109 (1); ZMA 100385-89 (12), 100404 (3), 100429 (1), 100433 (1), 100435 (3), 100437 (2), 100380 (1), 100384 (2), 113369 (2). Type catalog: Nijssen et al. 1982:71 [ref. 19236]. •Synonym of Rivulus ocellatus Hensel 1868 -- (Huber 1992:121 [ref. 20639]). •Synonym of Rivulus marmoratus Poey 1880 -- (Lazara 2001:280 [ref. 25711], Costa in Reis et al. 2003:537 [ref. 27061]). •Possibly valid, in Cryptolebias -- (Costa 2004:115 [ref. 27763]). •Possilby valid in Kryptolebias -- (Costa 2004:107 [ref. 28584]). •Synonym of Kryptolebias marmoratus (Poey 1880) -- (Costa 2006:6 [ref. 28624], Costa 2016:189 [ref. 34932], Faloh-Gandarilla et al. 2016:7 [ref. 35177]). Current status: Synonym of Kryptolebias marmoratus (Poey 1880). Rivulidae: Kryptolebiatinae. Habitat: freshwater.

bondi, Rivulus Schultz [L. P.] 1949:92, fig. 12 [Proceedings of the United States National Museum v. 99 (no. 3235); ref. 3967] Tributary to Río Guaire, La Florida, Caracas, Venezuela. Holotype: UMMZ 141914. Paratypes: MCUCV-V-7001 [ex UMMZ 141915] (10); UMMZ 141915 (111, 10 c&s), 141929 (9); USNM 122008 [ex UMMZ 141915] (15). Type catalog: Huber 1992 [ref. 20639], Provenzano et al. 1998:16 [ref. 24196]. •Synonym of Rivulus hartii (Boulenger 1890) -- (Huber 1992:125 [ref. 20639], Huber 1999:49 [ref. 23834], Lazara 2001:276 [ref. 25711], Costa in Reis et al. 2003:536 [ref. 27061]). •Valid as Anablepsoides bondi (Schultz 1949) -- (Costa 2011:243 [ref. 31655], Valdesalici 2015:241 [ref. 34049]). •Synonym of Anablepsoides hartii (Boulenger 1890). Current status: Synonym of Anablepsoides hartii (Boulenger 1890). Rivulidae: Rivulinae. Habitat: freshwater, brackish.

bonita, Hypsolebias Abrantes [Y. G.], Ramos [T. P. A.], Bento [D. M.] & Lima [S. M. Q.] 2023:552, Figs. 5-6, 8C [Zootaxa 5389 (no. 5); ref. 40706] Córrego Virgílio microbasin, Baraúna Municipality, Rio Grande do Norte State, Brazil, 05°02'55"S, 37°30'15"W. Holotype: MNRJ 54899. Paratypes: MZUSP, UFRN. •Valid as Hypsolebias bonita Abrantes, Ramos, Bento & Lima 2023. Current status: Valid as Hypsolebias bonita Abrantes, Ramos, Bento & Lima 2023. Rivulidae: Cynolebiinae. Distribution: South America: córrego Virgílio microbasin and the floodplains of the Rio Apodi-Mossoró basin, Rio Grande do Norte State, Brazil. Habitat: freshwater.

bororo, Rivulus Costa [W. J. E. M.] 2008:352, Figs. 1-2 [Ichthyological Exploration of Freshwaters v. 18 (no. 4) [for 2007]; ref. 29384] Swampy floodplans of córrego Buriti mouth, close to Santana River, upper Paraguay River basin, near the road MT-249 and the city of Arenápolis, 14°27'06"S, 56°49'00"W, Est. Mato Grosso, Brazil. Holotype: UFRJ 6500. Paratypes: UFRJ 6501 (5), 6502 (3 c&s), 6503 (2). •Valid as Melanorivulus bororo (Costa 2008) -- (Costa 2011:241 [ref. 31655], with date as 2007, Deprá et al. 2017:121 [ref. 35503]). Current status: Valid as Melanorivulus bororo (Costa 2008). Rivulidae: Rivulinae. Distribution: Upper Paraguay River basin, Brazil. Habitat: freshwater.

boticarioi, Aphyolebias Costa [W. J. E. M.] 2004:7, Figs. 4-5 [Zootaxa No. 707; ref. 27924] Temporary forest pool, rio Acre floodplains, rio Purus drainage, Rio Amazonas basin, 9°35'14.8"S, 67°31'57.0"W, Porto Acre, Estado do Acre, Brazil, elevation 133 meters. Holotype: UFRJ 5986. Paratypes: UFRJ 5987 (11), 5988 (4, 4 or 2 c&s). •Valid as Aphyolebias boticarioi Costa 2004 -- (Valdesalici et al. 2015:129 [ref. 33902]). •Valid as Moema boticarioi (Costa 2004) -- (Valdesalici 2016:71 [ref. 34174]). Current status: Valid as Moema boticarioi (Costa 2004). Rivulidae: Rivulinae. Distribution: Acre River floodplains, Purus River drainage, Amazon River basin, northwestern Brazil. Habitat: freshwater.

botocudo, Austrolebias Lanés [L. E. K.], Volcan [M. V.] & Maltchik [L.] 2021:501, Figs. 1-2, 9A-B [Zootaxa 4949 (no. 3); ref. 38189] Temporary pool near rio Socorro, rio Apuaê-Inhandava drainage, upper rio Uruguay basin, Vacaria, Rio Grande do Sul, Brazil, 28°22'43.6"S, 50°52'21.8"W, elevation 934 meters. Holotype: MCP 54450. Paratypes: MCP. •Valid as Austrolebias botocudo Lanés, Volcan & Maltchik 2021. •Valid as Garcialebias botocudo (Lanés, Volcan & Maltchik 2021) -- (Alonso et al. 2023:13 [ref. 40292]). Current status: Valid as Garcialebias botocudo (Lanés, Volcan & Maltchik 2021). Rivulidae: Cynolebiinae. Distribution: South America: grassland pools of upper Uruguay River basin, Rio Grande do Sul State, southern Brazil. Habitat: freshwater.

brasiliensis, Fundulus Valenciennes [A.] in Humboldt & Valenciennes 1821:163, Pl. 52 (figs. 3, 7) [Voyage de Humboldt et Bonpland v. 2 (Title page 1833); ref. 5612] Rio de Janeiro, Brazil. Neotype: MNHN 0000-2726. Possible syntypes: MNHN B-2950 [ex MNHN 0000-2726] (1), NMW 81111 (2). Type catalog: Bertin & Estève 1950:28 [ref. 19576]. Neotype designated by Huber 1992:131 [ref. 20639]; possible syntypes at MNHN need investigation. •Valid as Fundulus brasiliensis Valenciennes 1821 -- (Huber 1992:129 [ref. 20639]). •Valid as Rivulus brasiliensis (Valenciennes 1821) -- (Lazara 2001:271 [ref. 25711], Costa in Reis et al. 2003:535 [ref. 27061]). •Valid as Cryptolebias brasiliensis (Valenciennes 1821) -- (Costa 2004:115 [ref. 27763]). •Valid as Kryptolebias brasiliensis (Valenciennes 1821) -- (Costa 2004:107 [ref. 28584], Vermeulen & Hrbek 2005:7 [ref. 28142], Costa 2006:6 [ref. 28624], Costa 2007:12 [ref. 29397], Costa 2009:122 [ref. 30421], Carvalho-Filho 2023:94 [ref. 40480]). Current status: Valid as Kryptolebias brasiliensis (Valenciennes 1821). Rivulidae: Kryptolebiatinae. Distribution: South America: Atlantic coastal river basins (Brazil). Habitat: freshwater.

breviceps, Rivulus Eigenmann [C. H.] 1909:49 [Annals of the Carnegie Museum v. 6 (no. 1); ref. 1222] Shrimp Creek, near Kaituer, Guyana. Holotype: FMNH 52710 [ex CM 1075]. Paratypes: (4, CM and IU) BMNH 1911.10.31.531 (1), CAS 44211 [ex IU 11758] (3). Type catalog: Henn 1928:86 [ref. 12305], Ibarra & Stewart 1987:76 [ref. 12367], Huber 1992 [ref. 20639]. •Valid as Rivulus breviceps Eigenmann 1909 -- (Huber 1992:133 [ref. 20639], Vermeulen & Isbrücker 2000:190 [ref. 25219], Lazara 2001:271 [ref. 25711], Costa in Reis et al. 2003:535 [ref. 27061], Hrbek et al. 2004:573 [ref. 27910], Suijker & Collier 2006:10 [ref. 28729], Costa 2006:152 [ref. 28875] in subgenus Laimosemion). •Valid as Laimosemion breviceps (Eigenmann 1909) -- (Costa 2011:239 [ref. 31655], Vermeulen et al. 2012:187 [ref. 32253], Taphorn et al. 2022:36 [ref. 41297]). Current status: Valid as Laimosemion breviceps (Eigenmann 1909). Rivulidae: Rivulinae. Distribution: South America: Amazon River basin (Guyana) endemic. Habitat: freshwater.

brevirostrata, Pituna Costa [W. J. E. M.] 2007:6, Figs. 2-3 [Zootaxa No. 1410; ref. 28993] Goiânia, rio Meia Ponte flodplains, rio Paranaíba drainage, 16°38'29.8"S, 49°15'28.4"W, Estaqdo de Goiás, Brazil, elevation about 750 meters. Holotype: UFRJ 6427. Paratypes: MCP 40496 (2); UFRJ 6428 (6), 6429 (5, c&s). •Valid as Pituna brevirostrata Costa 2007. Current status: Valid as Pituna brevirostrata Costa 2007. Rivulidae: Rivulinae. Distribution: Temporary lagoon in Meia Ponte River floodplains, city of Goiânia, Goiás, central Brazil. Habitat: freshwater.

brevis, Rivulus Regan [C. T.] 1912:504 [Annals and Magazine of Natural History (Series 8) v. 10 (no. 59); ref. 3648] Northern Colombia. Holotype (unique): BMNH 1908.5.14.8. •Valid as Rachovia brevis (Regan 1912) -- (Taphorn & Thomerson 1978:389 [ref. 4337], Parenti 1981:486 [ref. 7066], Costa 1998:80 [ref. 23792], Lazara 2001:265 [ref. 25711], Costa in Reis et al. 2003:533 [ref. 27061], DoNascimiento et al. 2017:101 [ref. 35633], Berkenkamp 2020:10 [ref. 37695]). Current status: Valid as Rachovia brevis (Regan 1912). Rivulidae: Rivulinae. Distribution: Magdalena River and Lake Maracaibo basins: Colombia and Venezuela. Habitat: freshwater.

britzkei, Melanorivulus Nielsen [D. T. B.] 2017:60, Figs. 4-5 [aqua, International Journal of Ichthyology v. 23 (no. 2); ref. 35340] Rio São Bento, headwaters of rio Braço Norte, Novo Progresso, Pará, Brazil, 9°12'35"S, 54°52'7"W. Holotype: MZUSP 121646. Paratypes: MZUSP. •Valid as Melanorivulus britzkei Nielsen 2017 -- (Nielsen & Britzke 2019:41 [ref. 36525]). Current status: Valid as Melanorivulus britzkei Nielsen 2017. Rivulidae: Rivulinae. Distribution: Rio Teles Pires, rio Tapajós basin, Pará, Brazil. Habitat: freshwater.

brousseaui, Spectrolebias Nielsen [D. T. B.] 2013:82, Fig. 1 [Neotropical Ichthyology v. 11 (no. 1); ref. 32696] 47.5 km north of San José dos Chiqiutos, pool near of rio San Pablo, tributary of rio Mamoré, 17°25'31"S, 60°40'44"W. Dept. Santa Cruz, Bolivia. Holotype: MNKP 10162. Paratypes: MZUSP 109219 (3). •Valid as Spectrolebias brousseaui Nielsen 2013 -- (Nielsen & Brousseau 2013:121 [ref. 32794], Sarmiento et al. 2014:187 [ref. 35004], Nielsen & Pillet 2015:186 [ref. 34009], Loureiro et al. 2018:11 [ref. 36240] as Spetrolebias, Drawert 2023:14 [ref. 40730]). Current status: Valid as Spectrolebias brousseaui Nielsen 2013. Rivulidae: Cynolebiinae. Distribution: South America: tributary of rio Mamoré (Bolivia). Habitat: freshwater.

brucei, Campellolebias Vaz-Ferreira [R.] & Sierra de Soriano [B.] 1974:1, Pls. 1-2 [Comunicaciones Zoologicas del Museo de Historia Natural de Montevideo v. 10 (no. 138); ref. 4517] Temporary pool between Criciuma and Tubarão, Estado de Santa Catarina, Brazil. Holotype: ZVC-P 2116. Paratypes: ZVC-P 2121 (1), P 2127 (1); MHNM. Type catalog: Loureiro et al. 2016:412, 414 [ref. 35150]. •Valid as Campellolebias brucei Vaz-Ferreira & Sierra de Soriano 1974 -- (Costa et al. 1989:70 [ref. 9292], Costa 1995:100 [ref. 22097], Costa 1995:357 [ref. 22103], Costa 1998:74 [ref. 23792], Lazara 2001:69 [ref. 25711], Costa in Reis et al. 2003:528 [ref. 27061], Costa 2006:47 [ref. 28724], Ferrer et al. 2014:847 [ref. 33589], Costa et al. 2016:3 [ref. 34354], Costa 2016:129 [ref. 34776], Loureiro et al. 2018:11 [ref. 36240]). Current status: Valid as Campellolebias brucei Vaz-Ferreira & Sierra de Soriano 1974. Rivulidae: Cynolebiinae. Distribution: Coastal plains of southern Santa Catarina, Brazil. Habitat: freshwater.

brunneus, Rivulus Meek [S. E.] & Hildebrand [S. F.] 1913:86 [Field Museum of Natural History, Publications, Zoölogical Series v. 10 (no. 8); ref. 12295] Creek at Toro Point, Canal Zone, Panama. Holotype: FMNH 7593. Paratypes: FMNH 8821-27 (7); USNM 78871 (9), 78873 (now 0). Type catalog: Ibarra & Stewart 1987:76 [ref. 12367], Huber 1992 [ref. 20639]. •Valid as Rivulus brunneus Meek & Hildebrand 1913 -- (Huber 1992:136 [ref. 20639], Berkenkamp & Etzel 1992:97 [ref. 20601], Etzel & Berkenkamp 1992:29 [ref. 32437], Berkenkamp & Etzel 1993:86 [ref. 21583], Berkenkamp & Etzel 1997:131 [ref. 23635], Lazara 2001:271 [ref. 25711], Costa in Reis et al. 2003:535 [ref. 27061], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys). •Valid as Cynodonichthys brunneus (Meek & Hildebrand 1913) -- (Costa 2011:242 [ref. 31655]). Current status: Valid as Cynodonichthys brunneus (Meek & Hildebrand 1913). Rivulidae: Rivulinae. Distribution: Atlantic coastal river basins, Panama. Habitat: freshwater.

brunoi, Simpsonichthys Costa [W. J. E. M.] 2003:55, Fig. 13 [Ichthyological Exploration of Freshwaters v. 14 (no. 1); ref. 26758] Temporary pool near the city of Vila Boa, ribeirão Canabrava floodplains, upper rio Urucuia drainage [actual is rio Paraná drainage], rio São Francisco basin, 15°03'0.4"S, 47°04'3.3"W, Goiás State, Brazil, elevation 449 meters. Holotype: MCP 28576. Paratypes: MCP 28577 (7); UFRJ 5412-14 (8, 15, 17). •Valid as Simpsonichthys brunoi Costa 2003 -- (Costa 2006:17 [ref. 28620], Costa 2007:100 [ref. 29445], Costa 2008:156 [ref. 29874]). •Valid as Hypsolebias brunoi (Costa 2003) -- (based on generic placement in Costa 2011 [ref. 31654], Nielsen et al. 2012:70 [ref. 32283], Nielsen et al. 2014:28 [ref. 33143]). Current status: Valid as Hypsolebias brunoi (Costa 2003). Rivulidae: Cynolebiinae. Distribution: Cababrava River floodplains, Paraná River drainage, São Francisco River basin, Goiás, central Brazil. Habitat: freshwater.

caeruleus, Hypsolebias Costa [W. J. E. M.] 2013:142, Figs. 1-2 [Ichthyological Exploration of Freshwaters v. 24 (no. 2); ref. 33008] Estado da Bahia, Município de Itaguacu de Bahia, seasonal pool in the floodplains of the lower Verde River, a right tributary of the middle São Francisco River, about 30 km N of the town of Itaguacu, 10°43'20"S, 42°20'30"W, Brazil, elevation 414 meters. Holotype: UFRI 6864. Paratypes: UFRJ 6855 (3), 6854 (3), 6827 (2). •Valid as Hypsolebias caeruleus Costa 2013 -- (Nielsen et al. 2014:132 [ref. 33451], Silva et al. 2020:14 [ref. 37809]). Current status: Valid as Hypsolebias caeruleus Costa 2013. Rivulidae: Cynolebiinae. Distribution: South America: Rio Verde (Bahia State, Brazil). Habitat: freshwater.

cajariensis, Rivulus Costa [W. J. E. M.] & De Luca [A. C.] 2011:354, Fig. 1 [Ichthyological Exploration of Freshwaters v. 21 (no. 4) [Dec. 2010]; ref. 31193] Stream near Vila Cajari, upper Cajari River drainage, lower Amazon River basin, 0°34'23"S, 52°16'23"W, Estado do Amapá, northern Brazil, elevation 120 meters. Holotype: UFRJ 6771. Paratypes: UFRJ 6772 (1), 6773 (2, c&s). •Valid as Anablepsoides cajariensis (Costa & De Luca 2011) -- (Costa 2011:243 [ref. 31655], Valdesalici 2015:241 [ref. 34049]). Current status: Valid as Anablepsoides cajariensis (Costa & De Luca 2011). Rivulidae: Rivulinae. Distribution: Cajari River drainage, lower Amazon River basin, northern Brazil. Habitat: freshwater.

camaquensis, Austrolebias Volcan [M. V.], Gonçalves [Â. C.] & Lanés [L. E. K.] 2017:142, Figs. 1-5 [Zootaxa 4338 (no. 1); ref. 35644] Temporary pool in the floodplains of Arroio Santo Antônio (tributary of Rio Camaquã), close to BR-471 highway, Canguçu municipality, Rio Grande do Sul, Brazil, 30°58'25"S, 52°39'47"W. Holotype: MCP 50817. Paratypes: MCP. •Valid as Austrolebias camaquensis Volcan, Gonçalves & Lanés 2017. •Valid as Matilebias camaquensis (Volcan, Gonçalves & Lanés 2017) -- (Alonso et al. 2023:9 [ref. 40292]). Current status: Valid as Matilebias camaquensis (Volcan, Gonçalves & Lanés 2017). Rivulidae: Cynolebiinae. Distribution: South America: floodplain of the middle Rio Camaquã basin, Rio Grande do Sul, southeastern Brazil. Habitat: freshwater.

campelloi, Rivulus Costa [W. J. E. M.] 1990:42, Fig. 1 [Revue française d'Aquariologie Herpétologie v. 17 (no. 2); ref. 19597] Marsh near Primavera, Pará, Brazil. Holotype: ZVCM. Paratypes: ZVCM 0000 [sic] (1), ZVCM 0000 [sic] (1, c&s). •Valid as Rivulus campelloi Costa 1990 -- (Huber 1992:140 [ref. 20639], Lazara 2001:272 [ref. 25711], Costa in Reis et al. 2003:535 [ref. 27061]). •Valid as Cryptolebias campelloi (Costa 1990) -- (Costa 2004:115 [ref. 27763]). •Valid as Kryptolebias campelloi (Costa 1990) -- (Costa 2004:107 [ref. 28584], Vermeulen & Hrbek 2005:14 [ref. 28142], Costa 2006:6 [ref. 28624]). Current status: Valid as Kryptolebias campelloi (Costa 1990). Rivulidae: Kryptolebiatinae. Distribution: Lower Amazonas floodplains, Brazil. Habitat: freshwater.

canabravensis, Plesiolebias Costa [W. J. E. M.] & Nielsen [D. T. B.] in Costa 2007:31, Figs. 20-21 [Zootaxa No. 1410; ref. 28993] Temporary lagoon in left rio Canabrava floodplains, rio Santa Tereza drainage, rio Tocantins basin, road TO-373, between Alvorada and Peixe, 12°29'46.3"S, 49°00'50.7"W, Estado do Tocantins, Brazil, elevation 292 meters. Holotype: UFRJ 6424. Paratypes: MCP 40500 (6); UFRJ 3801 (55), 4600 (6, c&s), 6425 (20). The second author is D. T. B. Nielsen. •Valid as Plesiolebias canabravensis Costa & Nielsen 2007. Current status: Valid as Plesiolebias canabravensis Costa & Nielsen 2007. Rivulidae: Rivulinae. Distribution: Seasonal lagoon near Canabrava River, Tocantins River basin, Brazil. Habitat: freshwater.

canesi, Melanorivulus Nielsen [D. T. B.] 2017:57, Figs. 1-2 [aqua, International Journal of Ichthyology v. 23 (no. 2); ref. 35340] "Vereda" at Km 84, road BR-163, near to CPBV-FAB, Rio Curuá basin, Novo Progresso, Pará, Brazil, 8°53'18"S, 54°59'00"W. Holotype: MZUSP 121647. Paratypes: MZUSP. •Valid as Melanorivulus canesi Nielsen 2017 -- (Nielsen & Britzke 2019:41 [ref. 36525]). Current status: Valid as Melanorivulus canesi Nielsen 2017. Rivulidae: Rivulinae. Distribution: Rio Curuá, middle Rio Xingu basin, Pará, Brazil. Habitat: freshwater.

carlettoi, Simpsonichthys Costa [W. J. E. M.] & Nielsen [D. T. B.] 2004:126, Figs. 1-3 [aqua, Journal of Ichthyology and Aquatic Biology v. 8 (no. 3); ref. 27825] Temporary pool near Guanambi, off the road to Malhada, 14°13.989'S, 42°57.667'W, Bahia State, Brazil, elevation about 500 meters. Holotype: MCP 34089. Paratypes: UFRJ 5945 (2, 1 c&s), 5946 (1). •Valid as Hypsolebias carlettoi (Costa & Nielsen 2004) -- (Costa 2010:1999 [ref. 30858], but misspelled carletoi). •Valid as Simpsonichthys carlettoi Costa & Nielsen 2004 -- (Costa 2006:17 [ref. 28620], Costa 2007:89 [ref. 29445], Costa 2010:77 [ref. 30777]). •Valid as Hypsolebias carlettoi (Costa & Nielsen 2004) -- (based on generic placement in Costa 2011 [ref. 31654], Nielsen et al. 2014:132 [ref. 33451], Costa et al. 2018:499 [ref. 36319], Silva et al. 2020:14 [ref. 37809]). Current status: Valid as Hypsolebias carlettoi (Costa & Nielsen 2004). Rivulidae: Cynolebiinae. Distribution: South America: Rio das Rãs drainage, São Francisco River basin (Bahia State, Brazil). Habitat: freshwater.

carolinae, Rivulus Vermeulen [F. B. M.] & Mejia-Vargas [D. A.] 2020:23, Figs. 1-5 [Killi-Data Series 2020; ref. 37938] Small creek and surroundings about 10 minutes' walk south-southwest in the forest starting where airstrip ends, La Guadalupe, Alto Rio Negro, Departamento Guainía, Colombia, 1°13'58.46"N, 66°52'41.78"W, elevation 106 meters. Holotype: IAVHP 13656. Paratypes: IAVHP 13657 (6). •Valid as Laimosemion carolinae (Vermeulen & Mejia-Vargas 2020). Current status: Valid as Laimosemion carolinae (Vermeulen & Mejia-Vargas 2020). Rivulidae: Rivulinae. Distribution: South America: Alto Rio Negro, Colombia, near border with Venezuela and Brazil. Habitat: freshwater.

carvalhoi, Cynolebias Myers [G. S.] 1947:19 [Aquarium Journal v. 18 (no. 7); ref. 12307] Rio Iguassú [Iguaçú], near Porto Uniao [União], Santa Catarina, Brazil. Holotype: CAS 41178 (1 of 7). Paratypes: CAS 41178 (6 of 7). Lectotype as MNRJ 5759 designation by Costa 1998:308 is invalid since the holotype is available. See Huber 2006:22 [ref. 28935]. •Valid as Cynolebias carvalhoi Myers 1947 -- (Costa 1995:62 [ref. 22097], Costa 1998:308 [ref. 23665]). •Valid as Austrolebias carvalhoi (Myers 1947) -- (Costa 1998:75 [ref. 23792], Lazara 2001:60 [ref. 25711], Costa 2002:917 [ref. 26505], Costa in Reis et al. 2003:527 [ref. 27061], Costa et al. 2004:13 [ref. 27657], Costa 2006:90 [ref. 28708], Costa 2011:98 [ref. 31504], Costa 2014:97 [ref. 33514], Alonso et al. 2018:10 [ref. 35938], Reis et al. 2020:473 [ref. 38364], Lanés et al. 2021:513 [ref. 38189]). •Valid as Acrolebias carvalhoi (Myers 1947) -- (Alonso et al. 2023:12 [ref. 40292]). Current status: Valid as Acrolebias carvalhoi (Myers 1947). Rivulidae: Cynolebiinae. Distribution: South America: upper Iguaçú River basin (southern Brazil). Habitat: freshwater.

catimbau, Nematolebias Costa [W. J. E. M.], Amorim [P. F.] & Aranha [G. N.] 2014:230, Figs. 3-4 [Ichthyological Exploration of Freshwaters v. 24 (no. 3); ref. 33239] Estado do Rio de Janeiro: Município de Saquarema: temporary pool in Catimbau river floodplain, about 1.5 km south of Road RJ-106, Saquarema lagoon, system, 22°51'53"S, 42°33'15 W, Brazil. Holotype: UFRJ 8888. Paratypes: BMNH 2013.6.23.13-14 (2), UFMK and UFRJ. •Valid as Nematolebias catimbau Costa, Amorim & Aranha 2014. Current status: Valid as Nematolebias catimbau Costa, Amorim & Aranha 2014. Rivulidae: Cynolebiinae. Distribution: Catimbau River drainage, Rio de Janeiro State, Brazil. Habitat: freshwater.

caudomarginatus, Rivulus Seegers [L.] 1984:307, Figs. 10-11 [Zoologische Beiträge v. 28 (no. 2); ref. 17455] Greta [Grota] Funda near a technical center of the army, southeast of Rio de Janeiro, Brazil. Holotype: ZFMK 12848. Paratypes: BMNH 1983.6.9:16-19 (4); MZUSP uncat. (4?); RMNH 29219-20 (2, 2); SMF 17864 (4); ZFMK 12849 (1),12855-59 (5); ZMA 119096 (4); ZMB 31349 (4). Type catalog: Busse 1984:220 [ref. 28342], Paepke & Seegers 1986:169 [ref. 19981], Herder et al. 2010:125 [ref. 31087]. •Valid as Rivulus caudomarginatus Seegers 1984 -- (Huber 1992:143 [ref. 20639], Lazara 2001:272 [ref. 25711], Costa in Reis et al. 2003:535 [ref. 27061]). •Valid as Cryptolebias caudomarginatus (Seegers 1984) -- (Costa 2004:115 [ref. 27763]). •Synonym of Kryptolebias ocellatus (Hensel 1868) -- (Costa 2016:187 [ref. 34932]). •Valid as Kryptolebias caudomarginatus (Seegers 1984) -- (Costa 2004:107 [ref. 28584], Vermeulen & Hrbek 2005:7 [ref. 28142], Costa 2006:9 [ref. 28624], Costa 2011:186 [ref. 31358], Huber 2017:11 [ref. 35719], Carvalho-Filho 2023:94 [ref. 40480]). Current status: Valid as Kryptolebias caudomarginatus (Seegers 1984). Rivulidae: Kryptolebiatinae. Distribution: South America: coastal rivers and lagoons (Rio de Janeiro, Brazil). Habitat: freshwater.

caurae, Rivulus Radda [A. C.] 2004:24, Fig. 2 [Annalen des Naturhistorischen Museums in Wien v. 105 B; ref. 27638] Rio Caura, 1 kilometer from the village of El Playon towards the waterfall (Raudal Pará), 6°18'N, 64°25'W, Bolivar, Venezuela. Holotype: NMW 94902. Paratypes: NMW 94903 (8). •Valid as Anablepsoides caurae (Radda 2004) -- (Costa 2011:243 [ref. 31655]). Current status: Valid as Anablepsoides caurae (Radda 2004). Rivulidae: Rivulinae. Distribution: Caura River, Venezuela. Habitat: freshwater.

cearensis, Rivulus Costa [W. J. E. M.] & Vono [V.] 2009:8, Fig. 1 [Ichthyological Exploration of Freshwaters v. 20 (no. 1); ref. 30258] Município de São Gonçalo do Amarante, Pelém, Ceará State, Brazil, 22°10'50"S, 41°23.41'W. Holotype: UFRJ 6636. Paratypes: UFRJ 6637 (4), 6638 (3). Plus non-type material. •Valid as Anablepsoides cearensis (Costa & Vono 2009) -- (Costa 2011:243 [ref. 31655], Nielsen 2016:166 [ref. 34861]). Current status: Valid as Anablepsoides cearensis (Costa & Vono 2009). Rivulidae: Rivulinae. Distribution: São Gonçalo do Amarente, Ceará, northeastern Brazil. Habitat: freshwater.

chacoensis, Cynolebias Amato [L. H.] 1986:10, Pl. 5 (fig. 8), Pl. 6 (fig. 9) [Comunicaciones Zoologicas del Museo de Historia Natural de Montevideo v. 11 (no. 162); ref. 9170] Charca Topógrafo Acevedo, Nueva Asunción, Paraguay [ca. 21°00'S, 60°00'W]. Holotype: MHNM 2577. Paratypes: MHNM 2611-13 (1, 1, 3). Type catalog: Loureiro et al. 2016:412 [ref. 35150]. •Valid as Cynolebias chacoensis Amato 1986 -- (Costa 1995:55 [ref. 22097]). •Valid as Cynolebias ("Simpsonichthys") chacoensis Amato 1986 -- (Huber 1995:11 [ref. 22880]). •Valid as Simpsonichthys chacoensis (Amato 1986) -- (Costa 1996:130 [ref. 25271], Costa 1998:75 [ref. 23792], Lazara 2001:296 [ref. 25711], Costa in Reis et al. 2003:540 [ref. 27061], Costa 2006:17 [ref. 28620], Costa 2007:48 [ref. 29445], Costa & Brasil 2008:245 [ref. 29968]). •Valid as Spectrolebias chacoensis (Amato 1986) -- (Nielsen 2013:81 [ref. 32696], Nielsen & Brousseau 2013:116 [ref. 32794], Nielsen & Pillet 2015:186 [ref. 34009], Koerber et al. 2017:71 [ref. 35267], Costa & Amorim 2018:366 [ref. 36019]). Current status: Valid as Spectrolebias chacoensis (Amato 1986). Rivulidae: Cynolebiinae. Distribution: Paraguay River basin, Paraguay and Bolivia. Habitat: freshwater.

chapare, Anablepsoides Valdesalici [S.] & Gil [J. R. G.] 2017:12, Figs. 1-2 [aqua, International Journal of Ichthyology v. 23 (no. 1); ref. 35110] Small pool near Isinuta, Isiboro River drainage, tributary of Río Mamoré, Departamento Cochabamba, Chapare Province, Bolivia, 16°44'09.8"S, 65°37'58.4"W. Holotype: CIRA 3272. Paratypes: MSNG. •Valid as Anablepsoides chapare Valdesalici & Gil 2017 -- (Valdesalici & Gil 2019:152 [ref. 37074], Drawert 2023:21 [ref. 40730]). Current status: Valid as Anablepsoides chapare Valdesalici & Gil 2017. Rivulidae: Rivulinae. Distribution: South America: Río Mamoré drainage, upper Amazon basin (Bolivia). Habitat: freshwater.

charrua, Austrolebias Costa [W. J. E. M.] & Cheffe [M. M.] 2001:182, Figs. 2-3 [Comunicações do Museu de Ciências da PUCRS, Série Zoologia v. 14 (no. 2); ref. 25851] Temporary pool close to arroio Chuí, road to Barra do Chuí, rio Grande do Sul, Brazil. Holotype: MZUSP 60070. Paratypes: MCP 28027 (16); MUCP 2542 (16); MZUSP 60071 (5); UFRJ 4950 (47), 4990 (69), 5006 (10), 5009 (42), 5024 (4), 5061 (7, 4 c&s). •Valid as Austrolebias charrua Costa & Cheffe 2001 -- (Costa in Reis et al. 2003:527 [ref. 27061], Loureiro et al. 2004:27 [ref. 27658], Costa 2006:120 [ref. 28708], Costa 2009:188 [ref. 30417], Volcan et al. 2014:169 [ref. 33543], Litz & Koerber 2014:30 [ref. 33622], Bertaco et al. 2016:424 [ref. 34561], Nión et al. 2016:42 [ref. 35565], Costa et al. 2017:142 [ref. 35626], Loureiro et al. 2018:11 [ref. 36240], Fernandes et al. 2020:[3] 3 [ref. 38700], Volcan et al. 2021:104 [ref. 38292], Loureiro et al. 2023:167 [ref. 40506]). •Valid as Garcialebias charrua (Costa & Cheffe 2001) -- (Alonso et al. 2023:13 [ref. 40292], Koerber et al. 2023:10 [ref. 40355]). Current status: Valid as Garcialebias charrua (Costa & Cheffe 2001). Rivulidae: Cynolebiinae. Distribution: South America: coastal floodplains of southeastern Brazil and eastern Uruguay. Habitat: freshwater.

cheffei, Austrolebias Volcan [M. V.], Barbosa [C.], Robe [L. J.] & Lanés [L. E. K.] 2021:90, Figs. 1-2 [Zootaxa 4965 (no. 1); ref. 38292] Temporary pool in the floodplain of Rio Camaquã, Cristal municipality, Laguna dos Patos system, Rio Grande do Sul State, Brazil, 31°01'48"S, 52°00'32"W. Holotype: MCP 54437. Paratypes: MCP 54438 (13). •Valid as Austrolebias cheffei Volcan, Barbosa, Robe & Lanés 2021. •Valid as Garcialebias cheffei (Volcan, Barbosa, Robe & Lanés 2021) -- (Alonso et al. 2023:13 [ref. 40292]). Current status: Valid as Garcialebias cheffei (Volcan, Barbosa, Robe & Lanés 2021). Rivulidae: Cynolebiinae. Distribution: South America: temporary pools in the floodplain of the Rio Camaquã, Laguna dos Patos system, southeastern Brazil. Habitat: freshwater.

cheradophilus, Cynolebias Vaz-Ferreira [R.], Sierra de Soriano [B.] & Scaglia de Paulete [S.] 1965:14, Pls. 3-4 [Comunicaciones Zoologicas del Museo de Historia Natural de Montevideo v. 8 (no. 102) (for 25 June 1964); ref. 9087] Pool near Arroyo Valizas, 34°26'S, 53°46'W, Dept. of Rocha, Uruguay. Holotype: ZVC P.522. Paratypes: ZVC P.523 (1). Type catalog: Loureiro et al. 2016:414 [ref. 35150]. •Valid as Cynolebias cheradophilus Vaz-Ferreira, Sierra de Soriano & Scaglia de Paulete 1965 -- (Costa 1995:75 [ref. 22097], Berkenkamp et al. 1997:32 [ref. 23147]). •Valid as Megalebias cheradophilus (Vaz-Ferreira, Sierra de Soriano & Scaglia de Paulete 1965) -- (Costa 1998:76 [ref. 23792], Lazara 2001:203 [ref. 25711], Costa 2002:917 [ref. 26505], Costa in Reis et al. 2003:531 [ref. 27061]). •Valid as Austrolebias cheradophilus (Vaz-Ferreira, Sierra de Soriano & Scaglia de Paulete 1965) -- (Costa 2006:44 [ref. 28708], Costa 2009:188 [ref. 30417], Loureiro et al. 2011:341 [ref. 31392], Lanés et al. 2014:117 [ref. 33234], Litz & Koerber 2014:30 [ref. 33622], Bertaco et al. 2016:424 [ref. 34561], Nión et al. 2016:42 [ref. 35565] dated 1964, Loureiro et al. 2018:11 [ref. 36240], Loureiro et al. 2023:170 [ref. 40506]). •Valid as Titanolebias cheradophilus (Vaz-Ferreira, Sierra de Soriano & Scaglia de Paulete 1965) -- (Alonso et al. 2023:11 [ref. 40292], Koerber et al. 2023:11 [ref. 40355]). Current status: Valid as Titanolebias cheradophilus (Vaz-Ferreira, Sierra de Soriano & Scaglia de Paulete 1965). Rivulidae: Cynolebiinae. Distribution: South America: Atlantic coastal river basins, Laguna dos Patos system (southeastern Uruguay and Brazil). Habitat: freshwater.

cholopteryx, Simpsonichthys Costa [W. J. E. M.], Moreira [C. R.] & Lima [F. C. T.] 2003:140, Figs. 1-2 [aqua, Journal of Ichthyology and Aquatic Biology v. 6 (no. 4); ref. 26946] Rio Araguaia basin, on road MT 100, 31 kilometers south of Alto Araguaia, 17°33'38.5"S, 53°18'33.1"W, Ribeirão do Sapo, Estado de Mato Grosso, Brazil. Holotype: MZUSP 78061. Paratypes: MZUSP 73323 (41), 73338 (16, 6 c&s); UFRJ 5428 (29). Name to be treated as a noun in apposition. •Valid as Simpsonichthys cholopteryx Costa, Moreira & Lima 2003 -- (Costa 2006:17 [ref. 28620], Costa & Brasil 2006:221 [ref. 28843], Costa 2007:200 [ref. 29338], Costa 2007:26 [ref. 29445], Costa 2012:314 [ref. 31750], Nielsen et al. 2017:166 [ref. 35304]). Current status: Valid as Simpsonichthys cholopteryx Costa, Moreira & Lima 2003. Rivulidae: Cynolebiinae. Distribution: Upper Araguaia River basin, Mato Grosso, central Brazil. Habitat: freshwater.

christinae, Rivulus Huber [J. H.] 1992:147, Fig. 36, Pl. 39c [Review of Rivulus: Ecobiogeography -- Relationships; ref. 20639] Lago Tupac Amaru tributary, near Puerto Maldonado, Madre de Dios River, Depto. Madre de Dios, Peru. Holotype: NRM 16547. Paratypes: NRM 14655 (1), 14700 (10). •Valid as Rivulus christinae Huber 1992 -- (Lazara 2001:272 [ref. 25711], Costa in Reis et al. 2003:535 [ref. 27061], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys, Valdesalici & Schindler 2011:313 [ref. 31673] in subgenus Cynodonichthys). •Valid as Anablepsoides christinae (Huber 1992) -- (Costa 2011:243 [ref. 31655], Costa 2013:346 [ref. 32528], Valdesalici & Schindler 2013:299 [ref. 33109], Nielsen et al. 2016:76 [ref. 34406], Nielsen 2016:166 [ref. 34861], Valdesalici & Gil 2017:17 [ref. 35110], Valdesalici & Gil 2019:152 [ref. 37074], Drawert 2023:37 [ref. 40330], Drawert 2023:22 [ref. 40730]). Current status: Valid as Anablepsoides christinae (Huber 1992). Rivulidae: Rivulinae. Distribution: South America: upper Amazon basin (Peru); Rio Beni (Bolivia). Habitat: freshwater.

chrysolineatus, Campellolebias Costa [W. J. E. M.], Lacerda [M. T. C.] & Brasil [G. C.] 1989:69, Figs. 5-8 [Revue française d'Aquariologie Herpétologie v. 15 (no. 3) [for 1988]; ref. 9292] Pool at forest edge, 26°25'S, 48°38'W, Araquari, Santa Catarina, Brazil. Holotype: MZUSP 38817. Paratypes: MNRJ 11494 (2); MZUSP 38344 (11), 38818-19 (2, 1); ZVC P uncat. (2). •Valid as Campellolebias chrysolineatus Costa, Lacerda & Brasil 1989 -- (Costa 1995:99 [ref. 22097], Costa 1995:360 [ref. 22103], Costa 1998:74 [ref. 23792], Lazara 2001:69 [ref. 25711], Costa in Reis et al. 2003:529 [ref. 27061], Costa 2006:44 [ref. 28724], Ferrer et al. 2014:847 [ref. 33589], Costa 2016:129 [ref. 34776]). Current status: Valid as Campellolebias chrysolineatus Costa, Lacerda & Brasil 1989. Rivulidae: Cynolebiinae. Distribution: Coastal plains of northern Estado de Santa Catrina, Brazil. Habitat: freshwater.

chucunaque, Rivulus Breder [C. M., Jr.] 1925:7, Fig. 6 [American Museum Novitates No. 180; ref. 15531] Río Chucunaque, in a small side stream near Yavisa, Darien Province, Panama. Holotype: AMNH 8406. Paratypes: AMNH 22728-30 (8, 1, 14); USNM 94226 (8). •Valid as Rivulus chucunaque Breder 1925, subspecies chucunaque Breder 1925 -- (Lazara 2001:272 [ref. 25711], Etzel & Berkenkamp 1992:30 [ref. 32437]). •Valid as Rivulus chucunaque Breder 1925 -- (Huber 1992:150 [ref. 20639], Costa in Reis et al. 2003:535 [ref. 27061], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys). •Valid as Cynodonichthys chucunaque (Breder 1925) -- (Costa 2011:242 [ref. 31655]). Current status: Valid as Cynodonichthys chucunaque (Breder 1925). Rivulidae: Rivulinae. Distribution: Pacific river basins, Panama. Habitat: freshwater.

cinereus, Cynolebias Amato [L. H.] 1986:9, Pl. 6 (fig. 10) [Comunicaciones Zoologicas del Museo de Historia Natural de Montevideo v. 11 (no. 162); ref. 9170] Floodlands on route 21, 2 kilometers northwest of Viboras Creek, Colonia, Uruguay. Holotype: MHNM 2542. Paratypes: MHNM 2385 (2), 2533-35 (1, 1, 2), 2614 (1), 2615 (1), 2626 (15); ZVC-P 797 (49). Type catalog: Loureiro et al. 2016:412, 414 [ref. 35150]. •Valid as Cynolebias cinereus Amato 1986 -- (Costa 1995:70 [ref. 22097], Berkenkamp et al. 1997:32 [ref. 23147]). •Valid as Austrolebias cinereus (Amato 1986) -- (Costa 1998:75 [ref. 23792], Lazara 2001:61 [ref. 25711], Costa 2002:917 [ref. 26505], Calviño 2003:11 [ref. 26595], Costa in Reis et al. 2003:527 [ref. 27061], Costa et al. 2004:15 [ref. 27657], Costa 2006:31 [ref. 28708], Costa 2009:188 [ref. 30417], Costa 2011:100 [ref. 31504], Litz & Koerber 2014:30 [ref. 33622], Nión et al. 2016:42 [ref. 35565], Loureiro et al. 2018:11 [ref. 36240], García et al. 2019:[12] [ref. 36487], Koerber et al. 2020:9 [ref. 37480], Koerber et al. 2021:9 [ref. 38894], Loureiro et al. 2023:169 [ref. 40506]). •Valid as Cypholebias cinereus (Amato 1986) -- (Alonso et al. 2023:12 [ref. 40292], Koerber et al. 2023:10 [ref. 40355]). Current status: Valid as Cypholebias cinereus (Amato 1986). Rivulidae: Cynolebiinae. Distribution: South America: lower Paraná and Uruguay River basin and Laguna dos Patos system (Uruguay and Brazil). Habitat: freshwater.

citrinipinnis, Cynolebias Costa [W. J. E. M.], Lacerda [M. T. C.] & Tanizaki [K.] 1988:22, Fig. 1 [Revue française d'Aquariologie Herpétologie v. 15 (no. 1); ref. 9094] Pool in Município de Maricá, 22°S, 43°W, Rio de Janeiro State, Brazil. Holotype: MZUSP 37199. Paratypes: MNRJ 11310 (3); MZUSP 37197 (3), 37198 (6). •Synonym of Leptolebias opalescens (Myers 1942) -- (Lazara 2001:195 [ref. 25711]). •Synonym of Leptolebias fluminensis (Faria & Muller 1937) -- (Costa 1995:91 [ref. 22097]). •Valid as Leptolebias citrinipinnis (Costa, Lacerda & Tanizaki 1988) -- (Murphy & Collier 1997:797 [ref. 25585], Costa 1998:73 [ref. 23792], Costa in Reis et al. 2003:530 [ref. 27061], Costa 2008:155 [ref. 29596], Costa 2013:357 [ref. 32567], Ferrer et al. 2014:847 [ref. 33589]). •Valid as Leptopanchax citrinipinnis (Da Cruz 1974) -- (Costa 2016:128 [ref. 34776], Loureiro et al. 2018:11 [ref. 36240], Costa 2019:82 [ref. 36869]). Current status: Valid as Leptopanchax citrinipinnis (Costa, Lacerda & Tanizaki 1988). Rivulidae: Cynolebiinae. Distribution: Atlantic coastal river basins, southeastern Brazil. Habitat: freshwater.

cladophorus, Rivulus Huber [J. H.] 1991:71, Fig. 6 [Revue française d'Aquariologie Herpétologie v. 18 (no. 3); ref. 19721] Inner Guyana, 4°85'N, 53°30'W. Holotype: MNHN 1991-0364. Paratypes: ANSP 168824 (4); MNHN 1991-0365 and 0366 (4, 5); MNRJ 643 (4); USNM 320157 (4). •Valid as Rivulus cladophorus Huber 1991 -- (Huber 1992:154 [ref. 20639], Huber 1999:50 [ref. 23834], Keith et al. 2000:38 [ref. 24547], Lazara 2001:272 [ref. 25711], Costa in Reis et al. 2003:535 [ref. 27061], Keith et al. 2006:137 [ref. 28851], Costa 2006:152 [ref. 28875] in subgenus Laimosemion). •Valid as Laimosemion cladophorus (Huber 1991) -- (Costa 2011:239 [ref. 31655], Valdesalici & García Gil 2015:169 [ref. 34010]). Current status: Valid as Laimosemion cladophorus (Huber 1991). Rivulidae: Rivulinae. Distribution: Atlantic coastal river basins, French Guiana. Habitat: freshwater.

claudiae, Aphyolebias Costa [W. J. E. M.] 2003:158, Fig. 2A [Comunicações do Museu de Ciências e Tecnologia da PUCRS, Sér. Zoologia. v. 16 (no. 2); ref. 27616] Temporary pool at río San Pablo floodplains, on road Santa Cruz-Trinidad, río Guaporé basin, about 15°37'S, 63°35'W, Depart. Santa Cruz, Bolivia. Holotype: CBF 885. Paratypes: CBF 886 (6); UFRJ 4386 (4), 5470 (3, c&s). •Valid as Aphyolebias claudiae Costa 2003 -- (Valdesalici et al. 2015:129 [ref. 33902], Sarmiento et al. 2014:187 [ref. 35004]). •Valid as Moema claudiae (Costa 2003) -- (Valdesalici 2016:66 [ref. 34174], Drawert 2022:13 [ref. 39805], Drawert 2023:31 [ref. 40730]). Current status: Valid as Moema claudiae (Costa 2003). Rivulidae: Rivulinae. Distribution: South America: San Pablo River floodplains, Guaporé River basin (Bolivia). Habitat: freshwater.

coamazonicus, Hypsolebias Costa [W. J. E. M.], Amorim [P. F.] & Bragança [P. H. N.] 2014:4, Figs. 2a, 4 [Journal of Zoological Systematics and Evolutionary Research = Zeitschrift für zoologische Systematik und Evolutionsforschung v. 52 (no. 1); ref. 32952] Estado do Maranáo, Município de Araioses, seasonal pool close to the road between Pirangi and Araioses, Parnaíba River floodplains, 3°05'02"S, 41°53'56"W, Brazil, altitude about 20 meters. Holotype: UFRJ 8812. Paratypes: UFRJ 8760 (4), 8811 (3). Plus non-type material. •Valid as Hypsolebias coamazonicus Costa, Amorim & Bragança 2014 -- (Ramos et al. 2014:4 [ref. 35321], Britzke et al. 2016:134 [ref. 34461], Koerber et al. 2022:75 [ref. 39235], Abrantes et al. 2023:560 [ref. 40706]). Current status: Valid as Hypsolebias coamazonicus Costa, Amorim & Bragança 2014. Rivulidae: Cynolebiinae. Distribution: South America: Parnaíba River floodplains (northeastern Brazil). Habitat: freshwater.

collieri, Rivulus Huber [J. H.] 2021:4, Figs. 1-2 [Killi-Data Series 2021; ref. 38709] Isla Padre, a fluvial island in the Amazon River, just northeast of Iquitos, Maynas Province, Peru, 3.669S, 73.143W. Holotype: BMNH 1984.5.9.12. Paratypes: BMNH 1984.5.9.13-23 (11). Genus tentative. •Valid as Anablepsoides collieri (Huber 2021). Current status: Valid as Anablepsoides collieri (Huber 2021). Rivulidae: Rivulinae. Distribution: South America: middle Amazon River basin, Peru. Habitat: freshwater.

compactus, Rivulus Myers [G. S.] 1927:120 [Annals and Magazine of Natural History (Series 9) v. 19 (no. 109); ref. 3098] Rio Tocantins basin, Porto Nacional, Goays [now Estado do Tocantins], Brazil. Lectotype: CAS 40707. Paralectotypes: CAS 76511 (2). Lectotype selected by Huber 1992:157 [ref. 20639]. •Valid as Rivulus compactus Myers 1927 -- (Huber 1992:157 [ref. 20639]). •Valid as Pituna compacta (Myers 1927) -- (Costa 1991:332 [ref. 20644], Costa 1998:81 [ref. 23792], Costa 1998:141 [ref. 23879], Lazara 2001:251 [ref. 25711], Costa et al. 2003:144 [ref. 26946], Costa in Reis et al. 2003:533 [ref. 27061], Costa 2007:11 [ref. 28993]). Current status: Valid as Pituna compacta (Myers 1927). Rivulidae: Rivulinae. Distribution: Araguaia-Tocantins, Xingu and Paranaíba River basins, Brazil. Habitat: freshwater.

compressus, Rivulus Henn [A. W.] 1916:111, Pl. 18 (fig. 1) [Annals of the Carnegie Museum v. 10 (nos 1-2) (art. 9); ref. 2093] Manaus, Amazon River, Brazil [= 2 miles out of Manaos [Manaus], near mouth of rio Negro]. Holotype (unique): FMNH 57003 [ex CM 5819]. Type catalog: Henn 1928:86 [ref. 12305], Ibarra & Stewart 1987:76 [ref. 12367]. •Possible synonym of Rivulus micropus (Steindachner 1863) -- (Huber 1991:67 [ref. 19721]). •Status uncertain -- (Huber 1992:160 [ref. 20639]). •Valid as Rivulus compressus Henn 1916 -- (Costa in Reis et al. 2003:535 [ref. 27061], Hrbek et al. 2004:569 [ref. 27910]). •Synonym of Rivulus micropus (Steindachner 1863) -- (Lazara 2001:281 [ref. 25711], Costa 2006:145 [ref. 28875]). •Synonym of Anablepsoides micropus (Steindachner 1863). Current status: Synonym of Anablepsoides micropus (Steindachner 1863). Rivulidae: Rivulinae. Habitat: freshwater.

constanciae, Cynolebias Myers [G. S.] 1942:105 [Stanford Ichthyological Bulletin v. 2 (no. 4); ref. 3121] Cattle water hole, 10 miles north of Cabo Frio, [ca. 22°45'S, 42°00'W, elevation about 4 m], Rio de Janeiro State, Brazil. Holotype: CAS-SU 36514. Paratypes: CAS-SU 36515 (3). Type catalog: Böhlke 1953:52 [ref. 12291]. •Valid as Cynolebias constanciae Myers 1942 -- (Costa 1995:48 [ref. 22097], Costa 1996:130 [ref. 25271], Costa 1998:75 [ref. 23792]). •Valid as Simpsonichthys constanciae (Myers 1942) -- (Lazara 2001:296 [ref. 25711], Costa in Reis et al. 2003:541 [ref. 27061], Costa 2004:6 [ref. 27569], Costa 2007:14 [ref. 29445], Costa & Lima 2010:205 [ref. 31041], in subgenus Ophthalmolebias). •Valid as Ophthalmolebias constanciae (Myers 1942) -- (Loureiro et al. 2018:11 [ref. 36240]). Current status: Valid as Ophthalmolebias constanciae (Myers 1942). Rivulidae: Cynolebiinae. Distribution: Coastal plains adjacent to lower rio São João, Atlantic coastal drainage, southeastern Brazil. Habitat: freshwater.

corpulentus, Rivulus Thomerson [J. E.] & Taphorn [D. C.] 1993:58, Fig. 1 [Ichthyological Exploration of Freshwaters v. 4 (no. 1); ref. 20829] Small stream on Cordilleria de La Macarena flowing west, Departamento de Meta, Colombia, 2°25'N, 73°52'W. Holotype: CAS-SU [not CAS] 69692. Paratypes: CAS-SU [not CAS] 53693 (14). •Valid as Rivulus corpulentus Thomerson & Taphorn 1993 -- (Lazara 2001:272 [ref. 25711], Costa in Reis et al. 2003:535 [ref. 27061], Costa 2006:152 [ref. 28875] in subgenus Laimosemion). •Valid as Laimosemion corpulentus (Thomerson & Taphorn 1993) -- (Costa 2011:239 [ref. 31655], DoNascimiento et al. 2017:101 [ref. 35633]). •Valid as Anablepsoides corpulentus (Thomerson & Taphorn 1993) -- (Valdesalici & Gil 2017:16 [ref. 35110]). Current status: Valid as Anablepsoides corpulentus (Thomerson & Taphorn 1993). Rivulidae: Rivulinae. Distribution: Orinoco River basin, Colombia. Habitat: freshwater.

costai, Cynolebias Lazara [K. J.] 1991:144, Figs. 3, 5 [Journal of the American Killifish Association v. 23 (no. 5); ref. 20508] Temporary pool, Aruanã, Goiás State, Brazil [14°57'05"S, 51°01'23.7"W, elevation 243 meters]. Holotype: MZUSP 38790. Paratypes: AMNH 59190 (4), 59198 (2, c&s); MZUSP 38791 (1), 38792-93 (2). Mentioned earlier by Baker 1990:10 [ref. 36052] as Cynolebias costae, but without differential diagnosis (ICZN Art. 13.1.1), so the name is unavailable from that publication. •Valid as Cynolebias costai Lazara 1991 -- (Costa 1995:61 [ref. 22097]). •Valid as Simpsonichthys costai (Lazara 1991) -- (Costa 1996:130 [ref. 25271], Costa 1998:75 [ref. 23792], Costa & Le Bail 1999:1028 [ref. 24187], Lazara 2001:296 [ref. 25711], Costa et al. 2003:144 [ref. 26946], Costa in Reis et al. 2003:541 [ref. 27061], Costa and Nielsen 2003:122 [ref. 27246], Costa 2007:46 [ref. 29445], Costa & Brasil 2008:245 [ref. 29968]). •Valid of Spectrolebias costai (Lozara 1991) -- (Nielsen 2013:81 [ref. 32696], Nielsen & Brousseau 2013:116 [ref. 32794], Costa & Amorim 2018:365 [ref. 36019] as costae, Loureiro et al. 2018:11 [ref. 36240]). Current status: Valid as Spectrolebias costai (Lazara 1991). Rivulidae: Cynolebiinae. Distribution: Araguaia and Tocantins River basins, central Brazil. Habitat: freshwater.

cricarensis, Xenurolebias Costa [W. J. E. M.] in Costa & Amorim 2014:361, Figs. 6-7, 9 [Systematics and Biodiversity v. 12 (issue 3); ref. 33343] Temporary swamp about 1 km NW of the town of Conceição da Barra, São Mateus River basin, Conceição da Barra municipality, Espírito Santo State, Brazil, 18°34'01"S, 39°44'36"W. Holotype: UFRJ 9729. Paratypes: UFRJ. Plus additional non-type material. •Valid as Xenurolebias cricarensis Costa 2014 -- (Vieira-Guimarães et al. 2024:55 [ref. 41258]). Current status: Valid as Xenurolebias cricarensis Costa 2014. Rivulidae: Cynolebiinae. Distribution: South America: São Mateus River basin, northern Espírito Santo State (Brazil). Habitat: freshwater.

crixas, Rivulus Costa [W. J. E. M.] 2007:61, Figs. 6-7 [aqua, International Journal of Ichthyology v. 13 (no. 2); ref. 29394] Stream tributary to Rio Crixás Mirim, ca. 5 kilometers south of Nova Crixás, Rio Crixás Aça drainage, Rio Araguaia basin, at road GO-164 crossing, Goiás State, Brazil, 14°08'11.8"S, 50°21'15.5"W, elevation 284 meters. Holotype: UFRJ 6458. Paratypes: UFRJ 6459 (7), 6460 (5). •Valid as Rivulus crixas Costa 2007 -- (Costa 2010:369 [ref. 30690]). •Valid as Melanorivulus crixas (Costa 2007) -- (Costa 2011:241 [ref. 31655], Costa 2016:144 [ref. 34900], Costa et al. 2016:270 [ref. 35405], Nielsen 2017:67 [ref. 35340], Nielsen & Britzke 2019:42 [ref. 36525]). Current status: Valid as Melanorivulus crixas (Costa 2007). Rivulidae: Rivulinae. Distribution: Middle Araguaia River basin, central Brazil. Habitat: freshwater.

cruzi, Cynolebias Costa [W. J. E. M.] 1988:563, Figs. 3, 4g-4i [Revista Brasileira de Zoologia v. 5 (no. 4); ref. 14540] Marsh near Barra de São João, Casimiro de Abreu, RJ, Brazil. Holotype: MZUSP 36297. Paratypes: MNRJ 11289-91 (3, 6, 2); MZUSP 36298-99 (8, 8); personal coll. of Prof. Carlos A. G. Cruz CAGC124 (14). •Valid as Leptolebias cruzi (Costa 1988) -- (Costa 1995:90 [ref. 22097], Costa 1998:73 [ref. 23792], Costa & Le Bail 1999:1028 [ref. 24187], Lazara 2001:193 [ref. 25711], Costa in Reis et al. 2003:530 [ref. 27061]). •Valid as Notholebias cruzi (Costa 1988) -- (Costa 2008:157 [ref. 29596], Costa & Amorim 2013:67 [ref. 32799], Ferrer et al.2014:847 [ref. 33589], Costa 2016:128 [ref. 34776]). Current status: Valid as Notholebias cruzi (Costa 1988). Rivulidae: Cynolebiinae. Distribution: Atlantic coastal river basins, southeastern Brazil. Habitat: freshwater.

cryptocallus, Rivulus Seegers [L.] & Huber [J. H.] 1981:160, Figs. 1-5 [Senckenbergiana Biologica v. 61 (nos 3/4) (for 1980); ref. 8548] Ravine Vilaine, Martinique Island, West Indies. Holotype: MNHN 1979-0666. Paratypes: MNHN 1979-0667 (8 or 7), 1980-1452 (8), 1980-1453 (4); SMF 15364-67 (4), 15368-71 (4), 15372-75 (4), 15376-79 (4), 15380-83 (4); ZMA 112485-88 (12, 8, 4, 4), 112497-98 (7, 1). Type catalog: Nijssen et al. 1982:71 [ref. 19236]. Appeared first as unavailable name in Seegers 1980:141 [ref. 23122]. •Valid as Rivulus cryptocallus Seegers & Huber 1981 -- (Huber 1992:164 [ref. 20639], Lazara 2001:273 [ref. 25711] with author Seegers 1980, Lim et al. 2002:78 [ref. 28310], Costa in Reis et al. 2003:535 [ref. 27061] Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys). •Valid as Anablepsoides cryptocallus (Seegers & Huber 1981) -- (Costa 2011:243 [ref. 31655]). Current status: Valid as Anablepsoides cryptocallus (Seegers & Huber 1981). Rivulidae: Rivulinae. Distribution: River basins of Martinique Island, West Indies. Habitat: freshwater.

cryptocallus, Rivulus Seegers [L.] 1980:141, fig on p. 140 [Killifische. Eierlegende Zahnkarpfen im Aquarium; ref. 23122] Martinique Island, West Indies. Validly published by Seegers & Huber 1981:160, Figs. 1-5 [ref. 8548]. •In the synonymy of Anablepsoides cryptocallus (Seegers & Huber 1981). Current status: Synonym of Anablepsoides cryptocallus (Seegers & Huber 1981). Rivulidae: Rivulinae.

cyaneus, Cynolebias Amato [L. H.] 1987:2, Pls. 1-2 [Comunicaciones Zoologicas del Museo de Historia Natural de Montevideo v. 11 (no. 163); ref. 16152] Floodlands of Dom Marcos Creek, Municipio de Río Pardo, Río Grande do Sul, Brazil. Holotype: MCP 10441. Paratypes: MCP 10442-44 (1, 16, 20); MHNM 2468 (1), 2508-10 (4, 4, 1), 2593 (1), uncat. (1); MZUSP 36446-47 (1, 1). Type catalog: Loureiro et al. 2016:412 [ref. 35150]. •Valid as Cynolebias cyaneus Amato 1987 -- (Malabarba 1989:158 [ref. 14217], Costa 1999:301 [ref. 24229]). •Valid as Austrolebias cyaneus (Amato 1987) -- (Costa 1998:75 [ref. 23792], Lazara 2001:61 [ref. 25711], Costa & Cheffe 2001:180 [ref. 25851], Costa 2002:917 [ref. 26505], Costa in Reis et al. 2003:527 [ref. 27061], Costa 2006:78 [ref. 28708], Costa 2009:188 [ref. 30417], Bertaco et al. 2016:424 [ref. 34561], Volcan et al. 2017:150 [ref. 35644], Loureiro et al. 2018:11 [ref. 36240]). •Valid as Matilebias cyaneus (Amato 1987) -- (Alonso et al. 2023:9 [ref. 40292]). Current status: Valid as Matilebias cyaneus (Amato 1987). Rivulidae: Cynolebiinae. Distribution: South America: Jacuí River basin, Laguna dos Patos system, Río Grande do Sul, Brazil. Habitat: freshwater.

cyanopterus, Rivulus Costa [W. J. E. M.] 2005:73, Figs. 3-4 [Neotropical Ichthyology v. 3 (no. 1); ref. 28192] Jaciara, swamp close to rio Tenente Amaral, tributary to upper rio São Lourenço, rio Paraguay basin, 15°58;48.9"S, 54°57'20.0"W, elevation 246 meters. Holotype: UFRJ 5911. Paratypes: MCP 36121 (8); UFRJ 5912 (3), 5913 (36), 5914 (5, c&s). •Valid as Rivulus cyanopterus Costa 2005 -- (Costa 2006:162 [ref. 28875] in subgenus Melanorivulus). •Valid as Melanorivulus cyanopterus (Costa 2005) -- (Costa 2011:241 [ref. 31655], Costa 2017:68 [ref. 35046], Deprá et al. 2017:121 [ref. 35503]). Current status: Valid as Melanorivulus cyanopterus (Costa 2005). Rivulidae: Rivulinae. Distribution: Upper Sao Lourenço River drainage, Paraguay River basin, Brazil. Habitat: freshwater.

cylindraceus, Rivulus Poey [F.] 1860:308, 383 [Memorias sobre la historia natural de la Isla de Cuba v. 2; ref. 3499] Stream at Mordazo, near Havana, Cuba. Lectotype: MCZ 6423. Paralectotypes: MCZ 6395 (3), 99089 [ex 6423] (2). Type catalog: Howell Rivero 1938:176-177 [ref. 22926] with MCZ 6423 as the holotype, Faloh-Gandarilla et al. 2016:7 [ref. 35177]. No holotype was established; Huber 1992:168 incorrectly designated MCZ 6423 as the holotype; that specimen designated lectotype by Eschmeyer 1998:446. •Valid as Rivulus cylindraceus Poey 1860 -- (Huber 1992:168 [ref. 20639], Lazara 2001:273 [ref. 25711], Costa in Reis et al. 2003:535 [ref. 27061], Costa 2006:139 [ref. 28875], Costa 2011:239 [ref. 31655], Ponce de León et al. 2014:404 [ref. 33593], Rodriguez-Silva 2015:295 [ref. 33779], Faloh-Gandarilla et al. 2016:7 [ref. 35177]). Current status: Valid as Rivulus cylindraceus Poey 1860. Rivulidae: Rivulinae. Distribution: Coastal river basins, Cuba. Habitat: freshwater.

damascenoi, Plesiolebias Costa [W. J. E. M.] 1991:375, Figs. 14-15 [Ichthyological Exploration of Freshwaters v. 1 (no. 4); ref. 13611] Temporary pool, Poconé-Porto Cercado road, Mato Grosso, Brazil. Holotype: MZUSP 41391. Paratypes: MZUSP 41392 (2, c&s), 41393 (1). •Valid as Plesiolebias damascenoi Costa 1991 -- (Costa 1995:27 [ref. 22097], Costa 1995:70 [ref. 21612], Howe 1998:88 [ref. 25504], Britski et al. 1999:139 [ref. 24147]). •Valid as Stenolebias damascenoi (Costa 1991) -- (Costa 1998:81 [ref. 23792], Costa & Le Bail 1999:1028 [ref. 24187], Lazara 2001:303 [ref. 25711], Costa in Reis et al. 2003:542 [ref. 27061]). Current status: Valid as Stenolebias damascenoi (Costa 1991). Rivulidae: Rivulinae. Distribution: Paraguay River basin, Brazil. Habitat: freshwater.

dapazi, Rivulus Costa [W. J. E. M.] 2005:71, Fig. 1 [Neotropical Ichthyology v. 3 (no. 1); ref. 28192] Sonora, córrego Condusão, tributary to rio Correntes, rio Paraguy basin, 17°33'556.4"S, 54°44'23.8"W, Estado de Mato Grosso, Brazil, elevation 411 meters. Holotype: UFRJ 5915. Paratypes: MCP 36120 (9); UFRJ 5916 (3), 5917 (2, 1 c&s), 5918 (8), 5919 (2, c&s), 5920 (12), 5921 (3, 1c&s), 5922 (1), 5924 (3). •Valid as Rivulus dapazi Costa 2005 -- (Costa 2006:162 [ref. 28875] in subgenus Melanorivulus). •Valid as Melanorivulus dapazi (Costa 2005) -- (Costa 2011:241 [ref. 31655], Costa 2013:280 [ref. 33107], Nielsen & Pinto 2015:136 [ref. 33903], Costa et al. 2016:270 [ref. 35405], Costa 2017:64 [ref. 35046], Deprá et al. 2017:121 [ref. 35503]). Current status: Valid as Melanorivulus dapazi (Costa 2005). Rivulidae: Rivulinae. Distribution: Upper Correntes River drainage, Paraguay River basin, Brazil. Habitat: freshwater.

dariensis, Rivulus Bleher [H.] 1988:67, Fig. 4 [Tropical Fish Hobbyist v. 36 (no. 5) (no. 383); ref. 35198] Darien Province, Panama. Name only; not available. •In the synonymy of Cynodonichthys chucunaque (Breder 1925). Nomen Nudum. Current status: Synonym of Cynodonichthys chucunaque (Breder 1925). Rivulidae: Rivulinae.

decoratus, Rivulus Costa [W. J. E. M.] 1989:530, Figs. 6-6a [Revista Brasileira de Zoologia v. 6 (no. 3); ref. 14319] Near Rio Icatu falls, Ibiraba, Bahia State, Brazil. Holotype: MZUSP 39982. Paratypes: MZUSP 39983 (4). Type catalog: Huber 1992 [ref. 20639]. •Valid as Rivulus decoratus Costa 1989 -- (Huber 1992:173 [ref. 20639], Costa 1995:221 [ref. 21883], Lazara 2001:273 [ref. 25711], Costa 2003:41 [ref. 26966], Costa in Reis et al. 2003:535 [ref. 27061], Costa 2003:2 [ref. 27635], Costa 2006:162 [ref. 28875] in subgenus Melanorivulus, Costa 2010:194.3 [ref. 31043], Valdesalici et al. 2011:106 [ref. 31381]). •Valid as Melanorivulus decoratus (Costa 1989) -- (Costa 2011:241 [ref. 31655], Costa 2012:58 [ref. 32069], Costa et al. 2015:32 [ref. 33784], Costa 2017:64 [ref. 35046], Deprá et al. 2017:113 [ref. 35503], Silva et al. 2020:14 [ref. 37809]). Current status: Valid as Melanorivulus decoratus (Costa 1989). Rivulidae: Rivulinae. Distribution: South America: São Francisco River basin (Bahia State, Brazil). Habitat: freshwater.

degreefi, Rivulus Collier [G. E.] 2016:45, Figs. 5, 6a [Journal of the American Killifish Association v. 49 (no. 2) (for Mar./Apr.); ref. 35018] Small puddles next to Rio Oscura, 3-4 km upstream from where the river empties into Lago de Izabal, Guatemala. Holotype: UMMZ 250297. Paratypes: UMMZ. Genus tentative. •Valid as Cynodonichthys degreefi (Collier 2016). Current status: Valid as Cynodonichthys degreefi (Collier 2016). Rivulidae: Rivulinae. Distribution: Middle America: Rio Polochic valley, Guatemala. Habitat: freshwater.

deltaphilus, Rivulus Seegers [L.] 1983:39, Figs. 1-6 [Senckenbergiana Biologica v. 63 (nos 1/2) (for 1982); ref. 8281] Between Tucupita (9°05'N, 62°03'W) and Barancas (8°42'N, 62°11'W), Orinoco Delta, Venezuela. Holotype: SMF 16394. Paratypes: SMF 16395-96 (1, 9). •Status uncertain -- (Huber 1992:176 [ref. 20639]). •Valid as Rivulus deltaphilus Seegers 1983 -- (Lazara 2001:274 [ref. 25711], Costa in Reis et al. 2003:535 [ref. 27061], Radda 2004:21 [ref. 27638], Lasso-Alcalá et al. 2006:27 [ref. 28774], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys, Costa 2010:84 [ref. 30788]). •Valid as Anablepsoides deltaphilus (Seegers 1983) -- (Costa 2011:243 [ref. 31655], Costa et al. 2013:292 [ref. 33108], Nielsen 2016:166 [ref. 34861]). Current status: Valid as Anablepsoides deltaphilus (Seegers 1983). Rivulidae: Rivulinae. Distribution: Orinoco River basin, Venezuela. Habitat: freshwater.

delucai, Simpsonichthys Costa [W. J. E. M.] 2003:49, Fig. 9 [Ichthyological Exploration of Freshwaters v. 14 (no. 1); ref. 26758] Temporary pool near the city of Urucuia, rio Urucuia floodplains, rio São Francisco basin, about 16°08'S, 45°45'W, Minas Gerais State, Brazil, elevation 498 meters. Holotype: MCP 28572. Paratypes: MCP 28573 (1); UFRJ 5426-27 (17, 4). •Valid as Simpsonichthys delucai Costa 2003 -- (Costa 2006:17 [ref. 28620], Costa 2007:120 [ref. 29445], Costa 2008:156 [ref. 29874]). •Valid as Hypsolebias delucai (Costa 2003) -- (based on generic placement in Costa 2011 [ref. 31654]). Current status: Valid as Hypsolebias delucai (Costa 2003). Rivulidae: Cynolebiinae. Distribution: Urucuia River floodplains, São Francisco River basin, Minas Gerais State, Brazil. Habitat: freshwater.

depressus, Rivulus Costa [W. J. E. M.] 1991:585, Fig. 2 (not 3) [Revue Suisse de Zoologie v. 98 (no. 3); ref. 20033] Stream near Porto Seguro, River João de Tiba basin, Brazil. Holotype: UFPB 2213. Paratypes: UFPB 1749 (17, 2 c&s). •Valid as Rivulus depressus Costa 1991 -- (Huber 1992:179 [ref. 20639], Lazara 2001:274 [ref. 25711], Costa in Reis et al. 2003:535 [ref. 27061], Costa 2004:105 [ref. 27824], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys, Costa 2008:47 [ref. 29622] in subgenus Atlantirivulus, Costa 2008:135 [ref. 29871], Costa & De Luca 2009:73 [ref. 30257]). •Valid as Atlantirivulus depressus (Costa 1991) -- (Costa 1991) -- (Costa 2011:244 [ref. 31655], Silva et al. 2020:13 [ref. 37809], Vieira-Guimarães et al. 2024:54 [ref. 41258]). Current status: Valid as Atlantirivulus depressus (Costa 1991). Rivulidae: Rivulinae. Distribution: South America: Atlantic coastal river basins (Brazil). Habitat: freshwater.

derhami, Rivulus Fels [J. F.] & Huber [J. H.] 1985:33, Figs. 1-4 [Revue française d'Aquariologie Herpétologie v. 12 (no. 2); ref. 8162] In the area of Université d'Agronomie (Universidad Agraria) in Tingo Maria, central Peru, about 9°S, 75°55'W. Holotype: MNHN 1985-0577. Paratypes: MNHN 1985-0578 to 0582 (2, 9, 3, 4, 6); ZFMK 166-2071 to 2090 (20), 7813a (66). Type catalog: Herder et al. 2010:126 [ref. 31087]. •Valid as Rivulus derhami Fels & Huber 1985 -- (Huber 1992:181 [ref. 20639], Lazara 2001:274 [ref. 25711], Costa in Reis et al. 2003:535 [ref. 27061], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys). •Valid as Anablepsoides derhami (Fels & Huber 1985) -- (Costa 2011:243 [ref. 31655]). Current status: Valid as Anablepsoides derhami (Fels & Huber 1985). Rivulidae: Rivulinae. Distribution: Amazon River basin, Peru. Habitat: freshwater.

dibaphus, Rivulus Myers [G. S.] 1927:121 [Annals and Magazine of Natural History (Series 9) v. 19 (no. 109); ref. 3098] Igarapé do Ajamuri, Lower Amazon, Brazil. Lectotype: CAS 44214. Paralectotypes: CAS 44214-15 (10 [with lectotype], 6). Lectotype selected in Huber 1992:184 [ref. 20639]. The specific name dibaphus can be a noun or an adjective. Not specified by the author, so is to be treated as a noun (ICZN Art. 31.2.2). •Synonym of Rivulus geayi Vaillant 1899 -- (Huber 1991:70 [ref. 19721], Huber 1992:184 [ref. 20639], Huber 1999:50 [ref. 23834], Lazara 2001:275 [ref. 25711], Hrbek et al. 2004:569 [ref. 27910]). •Valid as Rivulus dibaphus Myers 1927 -- (Costa in Reis et al. 2003:535 [ref. 27061], Costa 2006:152, 155 [ref. 28875] in subgenus Laimosemion). •Valid as Laimosemion dibaphus (Myers 1927) -- (Costa 2011:239 [ref. 31655], Valdesalici & García Gil 2015:169 [ref. 34010]). Current status: Valid as Laimosemion dibaphus (Myers 1927). Rivulidae: Rivulinae. Distribution: South America: lower Amazon River basin, Brazil. Habitat: freshwater.

dolichopterus, Austrofundulus Weitzman [S. H.] & Wourms [J. P.] 1967:95, Figs. 1-2 [Copeia 1967 (no. 1); ref. 12488] Temporary pond south of Caño Benito, El Pao, Cojedes, Venezuela, 9°19'N, 68°09'W. Holotype: USNM 200784. Paratypes: CAS-SU 59635-37 (1, 2, 1); USNM 200785 (18). •Valid as Terranatos dolichopterus (Weitzman & Wourms 1967) -- (Costa 1995:21 [ref. 22097], Costa 1998:80 [ref. 23792], Lazara 2001:305 [ref. 25711], Costa in Reis et al. 2003:543 [ref. 27061], Reis et al. 2016:13 [ref. 34496]). Current status: Valid as Terranatos dolichopterus (Weitzman & Wourms 1967). Rivulidae: Rivulinae. Distribution: Orinoco River basin, Venezuela. Habitat: freshwater.

dorni, Rivulus Myers [G. S.] 1924:588 [Annals and Magazine of Natural History (Series 9) v. 13 (no. 78); ref. 15455] Rio de Janeiro, Brazil. Holotype: BMNH 1924.4.28.1. Paratypes: (7) AMNH 8277 (1), BMNH 1924.4.28.2 (1), CAS-SU 24076 (1), USNM 92966 (3). Type catalog: Böhlke 1953:54 [ref. 12291]. •Synonym of Rivulus brasiliensis (Valenciennes 1821) -- (Huber 1992:129, 187 [ref. 20639], Lazara 2001:271 [ref. 25711], Costa in Reis et al. 2003:535 [ref. 27061], Costa 2004:115 [ref. 27763]). •Synonym of Cryptolebias brasiliensis (Valenciennes 1821) -- (Costa 2004:115 [ref. 27763]). •In genus Kryptolebias. Current status: Synonym of Kryptolebias brasiliensis (Valenciennes 1821). Rivulidae: Kryptolebiatinae. Habitat: freshwater.

dorsimaculatus, Campellolebias Costa [W. J. E. M.], Lacerda [M. T. C.] & Brasil [G. C.] 1989:66, Figs. 2-3 [Revue française d'Aquariologie Herpétologie v. 15 (no. 3) [for 1988]; ref. 9292] Pool at forest edge, 24°37'S, 47°30'W [corrected to 24°40'0.4"S, 47°26'4.4"W, alt. 10 m], Iguapé, Estado de São Paulo, Brazil. Holotype: MZUSP 38813. Paratypes: MNJR 11493 (2); MZUSP 38814-16 (1, 12, 9); ZVC P uncat. (2). •Valid as Campellolebias dorsimaculatus Costa, Lacerda & Brasil 1989 -- (Costa 1995:97 [ref. 22097], Costa 1995:363 [ref. 22103], Costa 1998:74 [ref. 23792], Lazara 2001:69 [ref. 25711], Costa in Reis et al. 2003:529 [ref. 27061], Costa 2006:36 [ref. 28724], Ferrer et al. 2014:847 [ref. 33589], Costa 2016:129 [ref. 34776]). Current status: Valid as Campellolebias dorsimaculatus Costa, Lacerda & Brasil 1989. Rivulidae: Cynolebiinae. Distribution: Ribeira de Iguapé River basin, Brazil. Habitat: freshwater.

duckensis, Rivulus Hrbek [T.], de Deus [C. P.] & Farias [I. P.] 2004:571, Fig. 2 [Copeia 2004 (no. 3); ref. 27910] Rivulet emptying into Igarapé Barro Branco, Reserva Adolpho Ducke, Manaus, Amazonas, 2°53'S, 59°58'W, Brazil. Holotype: INPA 21444. Paratypes: INPA 21442 (6), 21443 (11); MZUSP 84223 (2); NMRJ 26192 (2). Plus non-type material. See Costa 2006:167 [ref. 28875] for dates of publication of duckensis (20 Aug.) and kirovskyi (30 Apr.). •Synonym of Rivulus kirovskyi Costa 2004 -- (Costa 2006:157 [ref. 28875] in subgenus Owiyeye). •Synonym of Laimosemion kirovskyi (Costa 2004) based on placement of kirovskyi -- (Costa 2011:239 [ref. 31655]). Current status: Synonym of Laimosemion kirovskyi (Costa 2004). Rivulidae: Rivulinae. Distribution: Tarumã basin, Amazonas, Brazil [if valid]. Habitat: freshwater.

duraznensis, Cynolebias Reichert [J. J.] 1992:58 [Deutsche Killifisch Gemeinschaft Journal v. 24 (no. 4); ref. 22100] Not available, no diagnostic features presented (names published after 1930, Art. 13.1.1 of the Code) for a species from Uruguay (see Costa 1995:125 [ref. 22097]). Also appeared in other papers and abstracts but without sufficient distinguishing features. See also Huber 2006:23 [ref. 28935]. •Validly published as Cynolebias duraznensis García, Scvortzoff & Hernández 1995. •In the synonymy of Matilebias duraznensis (García, Scvortzoff & Hernández 1995). Nomen Nudum. Current status: Synonym of Matilebias duraznensis (García, Scvortzoff & Hernández 1995). Rivulidae: Cynolebiinae.

duraznensis, Cynolebias García [G.], Scvortzoff [E.] & Hernández [A.] 1995:103 et seq. [Cytologia v. 60 (no. 2); ref. 25790] Durazno, Uruguay. Syntypes: whereabouts unknown. See discussion in Lazara 2001:61 [ref. 25711]. •Synonym of Austrolebias affinis (Amato 1986) -- (Costa in Reis et al. 2003:527 [ref. 27061], Koerber & Litz 2014:5 [ref. 34967], Koerber & Litz 2016:7 [ref. 35098]). •Valid as Austrolebias duraznensis (García, Scvortzoff & Hernández 1995) -- (Lazara 2001:61 [ref. 25711], Costa 2006:74 [ref. 28708], Costa 2009:188 [ref. 30417], Litz & Koerber 2014:30 [ref. 33622], Nión et al. 2016:42 [ref. 35565], Loureiro et al. 2018:11 [ref. 36240], Loureiro et al. 2023:166 [ref. 40506]). •Valid as Matilebias duraznensis (García, Scvortzoff & Hernández 1995) -- (Alonso et al. 2023:9 [ref. 40292], Koerber et al. 2023:11 [ref. 40355]). Current status: Valid as Matilebias duraznensis (García, Scvortzoff & Hernández 1995). Rivulidae: Cynolebiinae. Distribution: South America: lower Negro River basin (Uruguay). Habitat: freshwater.

egens, Rivulus Costa [W. J. E. M.] 2005:80, Fig. 11 [Neotropical Ichthyology v. 3 (no. 1); ref. 28192] Município de Camapuã, road BR-060, rio São Domingos, upper rio Verde drainage, rio Paraná basin, 19°19'26.0"S, 53°21'6.8"W, Estsdo de Mato Grosso do Sul, Brazil, elevation 532 meters. Holotype: UFRJ 5973. Paratypes: MCP 36126 (3); UFRJ 5974 (114), 5975 (3, c&s). Plus non-type material. •Valid as Rivulus egens Costa 2005 -- (Costa 2006:162 [ref. 28875] in subgenus Melanorivulus). •Valid as Melanorivulus egens (Costa 2005) -- (Costa 2011:241 [ref. 31655], Nielsen et al. 2016:87 [ref. 34407], Costa et al. 2016:270 [ref. 35405], Volcan et al. 2017:92 [ref. 35156], Volcan et al. 2018:275 [ref. 35895], Volcan et al. 2024:1499 [ref. 41484]). Current status: Valid as Melanorivulus egens (Costa 2005). Rivulidae: Rivulinae. Distribution: South America: Rio Verde drainage, Paraná River basin, Brazil. Habitat: freshwater.

elegans, Cynolebias Costa [W. J. E. M.] 2017:334, Figs. 1-2 [Zoosystematics and Evolution v. 93 (no. 2); ref. 35623] Temporary pool close to road BR-122, about 8 km S of the village of Pindaí, Mata Veado Creek floodplains, Verde Grande River drainage, São Francisco River basin, Pindaí municipality, Bahia State, Brazil, 14°33'39"S, 42°42'10"W, elevation about 630 meters. Holotype: UFRJ 9431. Paratypes: UFRJ. •Valid as Cynolebias elegans Costa 2017 -- (Silva et al. 2020:13 [ref. 37809]). Current status: Valid as Cynolebias elegans Costa 2017. Rivulidae: Cynolebiinae. Distribution: South America: Rio Verde Grande drainage, São Francisco River basin (Bahia State, Brazil). Habitat: freshwater.

elegans, Pterolebias Ladiges [W.] 1958:76, Fig. [Die Aquarien- und Terrarienzeitschrift (DATZ) v. 11 (no. 3); ref. 12082] Cabo Frio near Rio de Janeiro, about 22°50'S, 42°05'W, Brazil. Holotype (unique): ZMH H324. Type catalog: Wilkens 1977:159 [ref. 22013]. •Synonym of Cynolebias whitei Myers 1942 -- (Costa 1995:43 [ref. 22097]). •Synonym of Simpsonichthys whitei (Myers 1942) -- (Costa 1996:130 [ref. 25271]). •Synonym of Nematolebias whitei (Myers 1942) -- (Lazara 2001:213 [ref. 25711], Costa 2002:45 [ref. 26064], Costa in Reis et al. 2003:532 [ref. 27061]). Current status: Synonym of Nematolebias whitei (Myers 1942). Rivulidae: Cynolebiinae. Habitat: freshwater.

elegans, Rivulus Steindachner [F.] 1880:85 [33], Pl. 6 (fig. 6) [Denkschriften der Kaiserlichen Akademie der Wissenschaften in Wien, Mathematisch-Naturwissenschaftliche Classe. v. 42; ref. 14403] Río Cauca, Colombia. Lectotype: NMW 60544:1. Paralectotypes: NMW 60544:2-3 (2), 18893-6 (1, 1, 1, 1). On p. 33 of separate. Lectotype selected in Huber 1992:190 [ref. 20639]. •Valid as Rivulus elegans Steindachner 1880 -- (Huber 1992:190 [ref. 20639], Lazara 2001:274 [ref. 25711], Costa in Reis et al. 2003:536 [ref. 27061], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys, Vermeulen 2013:44 [ref. 33089] in subgenus Cynodonichthys). •Valid as Cynodonichthys elegans (Steindachner 1880) -- (Costa 2011:242 [ref. 31655], DoNascimiento et al. 2017:101 [ref. 35633]). Current status: Valid as Cynodonichthys elegans (Steindachner 1880). Rivulidae: Rivulinae. Distribution: Pacific coastal river basins, Antioquia, Colombia. Habitat: freshwater.

elongatus, Cynolebias Steindachner [F.] 1881:98 [Anzeiger der Akademie der Wissenschaften in Wien, Mathematisch-Naturwissenschaftliche Klasse v. 18 (no. 11) (for 5 May 1881); ref. 20484] La Plata, Argentina. Holotype (unique): NMW 76518. Species described in more detail in Steindachner 1881:11 [ref. 14299]. •Valid as Cynolebias elongatus Steindachner 1881 -- (Costa 1995:78 [ref. 22097]). •Valid as Megalebias elongatus (Steindachner 1881) -- (Costa 1998:76 [ref. 23792], Lazara 2001:203 [ref. 25711], Costa 2002:917 [ref. 26505], López et al. 2002:61 [ref. 26808], Costa in Reis et al. 2003:531 [ref. 27061], López et al. 2003:69 [ref. 27366], Menni 2004:86 [ref. 28131]). •Valid as Austrolebias elongatus (Steindachner 1881) -- (Costa 2006:57 [ref. 28708], Costa 2009:188 [ref. 30417], Koerber 2011:7 [ref. 31122], Lanés et al. 2014:17 [ref. 33234], Koerber 2014:11 [ref. 33621], Litz & Koerber 2014:30 [ref. 33622], Mirande & Koerber 2015:51 [ref. 35117], Alonso et al. 2016:6 [ref. 34643], Calviño et al. 2016:9 [ref. 34699], Nión et al. 2016:42 [ref. 35565], Loureiro et al. 2018:11 [ref. 36240], Loureiro et al. 2023:170 [ref. 40506]). •Valid as Titanolebias elongatus (Steindachner 1881) -- (Alonso et al. 2023:12 [ref. 40292], Koerber et al. 2023:11 [ref. 40355], Koerber et al. 2023:4 [ref. 40368]). Current status: Valid as Titanolebias elongatus (Steindachner 1881). Rivulidae: Cynolebiinae. Distribution: South America: lower Río de la Plata basin (Argentina and Uruguay). Habitat: freshwater.

elongatus, Rivulus Fels [J. F.] & de Rham [P.] 1981:66, Fig. [Revue française d'Aquariologie Herpétologie v. 8 (no. 3); ref. 8607] "Bosque Nacional Alexander von Humbolt", 8°42'S, 75°12'W, 86 kilometers from Pucallpa on Pucallpa-Tingo Maria Road, Peru. Holotype: MHNG 2079.63. Paratypes: MHNG 2079.64-67 (4), MNHN 1981-1270 (4). Type catalog: Weber 1998:11 [ref. 32707]. •Valid as Rivulus elongatus Fels & de Rham 1981 -- (Ortega & Vari 1986:19 [ref. 9708], Huber 1992:193 [ref. 20639], Lazara 2001:274 [ref. 25711], Costa in Reis et al. 2003:536 [ref. 27061], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys, Barriga Salazar 2014:117 [ref. 35745]). •Valid as Anablepsoides elongatus (Fels & de Rham 1981) -- (Costa 2011:243 [ref. 31655], Costa 2013:346 [ref. 32528], Nielsen et al. 2016:70 [ref. 34406], Nielsen 2016:166 [ref. 34861], DoNascimiento et al. 2017:101 [ref. 35633], Valdesalici & Gil 2019:152 [ref. 37074]). Current status: Valid as Anablepsoides elongatus (Fels & de Rham 1981). Rivulidae: Rivulinae. Distribution: Upper Amazon basin: Ecuador, Peru and Colombia. Habitat: freshwater.

enigmaticus, Atlantirivulus Volcan [M. V.], Suárez [Y. R.], Severo-Neto [F.], Amorim [P. F.] & Costa [W. J. E. M.] 2024:94, Figs. 2-5 [Zoologischer Anzeiger v. 312; ref. 41345] Unnamed first order stream, in the headwaters of the Iguirá-Moroti River along the border of road MS 386, Iguatemi River basin, municipality of Amambaí, Mato Grosso do Sul State, Brazil, 23°29'01"S, 54°51'45"W, elevation about 300 meters. Holotype: ZUFMS 8323. Paratypes: UFRJ, ZUFMS. •Valid as Atlantirivulus enigmaticus Volcan, Suárez, Severo-Neto, Amorim & Costa 2024. Current status: Valid as Atlantirivulus enigmaticus Volcan, Suárez, Severo-Neto, Amorim & Costa 2024. Rivulidae: Rivulinae. Distribution: South America: Iguatemi River drainage, Paraná River basin, Mato Grosso do Sul State, Brazil. Habitat: freshwater.

ephemerus, Austrolebias Volcan [M. V.] & Severo-Neto [F.] 2019:543, Figs. 1-4, 9 [Zootaxa 4560 (no. 3); ref. 36539] Temporary pool near "do Bala" Road, Porto Murtinho, Mato Grosso do Sul State, Brazil, 21°41'34"S, 57°42'57"W. Holotype: ZUFMS 5465. Paratypes: MCP, ZUFMS. •Valid as Austrolebias ephemerus Volcan & Severo-Neto 2019 -- (Alonso et al. 2023:10 [ref. 40292]). Current status: Valid as Austrolebias ephemerus Volcan & Severo-Neto 2019. Rivulidae: Cynolebiinae. Distribution: South America: Rio Paraguai basin, Mato Grosso do Sul State, Brazil. Habitat: freshwater.

erberi, Rivulus Berkenkamp [H. O.] 1989:211, Fig. [Das Aquarium, Zeitschrift für Aquarien- und Terrarienfreunde v. 23 (no 238); ref. 16217] 7 kilometers east of Coca (=Puerto Francisco de Orellana), near Río Napo, Napo Province, east Ecuador, 4°30'S, 76°54'W. Holotype: SMF 18432. Paratypes: MHNG 22281.04 (2), SMF 18433 (4), ZFMK 14820-22 (3). Type catalog: Huber 1992 [ref. 20639], Herder et al. 2010:126 [ref. 31087]. •Status uncertain -- (Huber 1992:196 [ref. 20639]). •Valid as Rivulus erberi Berkenkamp 1989 -- (Lazara 2001:274 [ref. 25711], Costa in Reis et al. 2003:536 [ref. 27061], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys, Valdesalici & Schindler 2011:313 [ref. 31673] in subgenus Cynodonichthys, Barriga Salazar 2014:117 [ref. 35745] as erberl). •Valid as Anablepsoides erberi (Berkenkamp 1989) -- (Costa 2011:243 [ref. 31655] Valdesalici & Schindler 2013:296 [ref. 33109], Valdesalici & Gil 2019:152 [ref. 37074]). Current status: Valid as Anablepsoides erberi (Berkenkamp 1989). Rivulidae: Rivulinae. Distribution: Napo River drainage, upper Amazon basin, Ecuador. Habitat: freshwater.

espinhacensis, Simpsonichthys Nielsen [D. T. B.], Pessali [T. C.] & Dutra [G. M.] 2017:166, Figs. 1-2 [Zootaxa 4263 (no. 1); ref. 35304] Vereda Volta da Capoeira, tributary of Ribeirão da Areia, Rio Jequitinhonha basin, Olhos D ́água, Minas Gerais, Brazil, 17°15'29.54"S, 43°43'10.10"W, elevation 775-800 meters. Holotype: MCNIP 1792. Paratypes: MCNIP, MPEG, MZUSP, ZUEC. •Valid as Simpsonichthys espinhacensis Nielsen, Pessali & Dutra 2017 -- (Vieira-Guimarães et al. 2024:55 [ref. 41258]). Current status: Valid as Simpsonichthys espinhacensis Nielsen, Pessali & Dutra 2017. Rivulidae: Cynolebiinae. Distribution: South America: upper Rio Jequitinhonha basin, Minas Gerais (Brazil). Habitat: freshwater.

falconi, Anablepsoides Nielsen [D. T. B.], Hoetmer [J. W.] & Vandenkerkhove [E.] 2023:299 [Zootaxa 5323 (no. 2); ref. 40342] Rio Tarauacá, upper Rio Juruá drainage, Amazon basin, Feijó, Acre, Brazil, 8°11'1.2"S, 70°30'15.3"W. Holotype: ZUEC 17362. Paratypes: ZUEC 17363 (2), 17364 (6). Appeared first in an unavailable publication, ref. 39105, p. 31, Figs. 4-5. •Valid as Anablepsoides falconi Nielsen, Hoetmer & Vandenkerkhove 2023. Current status: Valid as Anablepsoides falconi Nielsen, Hoetmer & Vandenkerkhove 2023. Rivulidae: Rivulinae. Distribution: South America: Rio Juruá drainage, Amazon basin, Brazil. Habitat: freshwater.

faouri, Hypsolebias Britzke [R.], Nielsen [D. T. B.] & Oliveira [C.] 2016:125, Figs. 1-2 [Zootaxa 4114 (no. 2); ref. 34461] Bahia, Prazeres, Rio Preto, Rio São Francisco basin, Brazil, 11°23'24.8"S, 44°54'11.2W, altitude 522 meters. Holotype: ZUEC 10796. Paratypes: LBP, ZUEC. •Valid as Hypsolebias faouri Britzke, Nielsen & Oliveira 2016 -- (Silva et al. 2020:14 [ref. 37809], Abrantes et al. 2023:549 [ref. 40706]). Current status: Valid as Hypsolebias faouri Britzke, Nielsen & Oliveira 2016. Rivulidae: Cynolebiinae. Distribution: South America: Rio Preto floodplains, Rio São Francisco basin (Bahia State, Brazil). Habitat: freshwater.

fasciatus, Simpsonichthys Costa [W. J. E. M.] & Brasil [G. C.] 2006:46, Figs. 4-5 [Zootaxa No. 1244; ref. 28725] Temporary pool about 2 kilometers from right bank of rio Preto, rio Paracatu drainage, rio São Francisco basin, about 16°41'30"S, 46°30'00"W, Unaí, Estado de Minas Gerais, Brazil, elevation about 550 meters. Holotype: UFRJ 6339. Paratypes: MCP 39436 (3); UFRJ 6340 (7), 6341 (4, c&s), 6372 (7), 6377 (1). •Valid as Simpsonichthys fasciatus Costa & Brasil 2006 -- (Costa 2007:124 [ref. 29445], Costa 2008:156 [ref. 29874]). •Valid as Hypsolebias fasciatus (Costa & Brasil 2006) -- (based on generic placement in Costa 2011 [ref. 31654]). Current status: Valid as Hypsolebias fasciatus (Costa & Brasil 2006). Rivulidae: Cynolebiinae. Distribution: Middle Preto River drainage, São Francisco River basin, Unaí, Minas Gerais State, Brazil. Habitat: freshwater.

faucireticulatus, Rivulus Costa [W. J. E. M.] 2008:314, Figs. 1-2 [Ichthyological Exploration of Freshwaters v. 18 (no. 4) [for 2007]; ref. 29388] Bonfim River floodplains, upper Claro River drainage, upper Paraná River basin, road GO-516, 10 kilometers west of the city of Perolândia, 17°31'31"S, 52°07'52"W, Munic. de Perolândia, Est. de Goiás, Brazil, elevation 787 meters. Holotype: UFRJ 6547. Paratypes: UFRJ 6548 (7), 6549 (3, c&s). •Valid as Rivulus faucireticulatus Costa 2008 -- (Costa 2008:86 [ref. 29717], Costa 2010:197 [ref. 31043]). •Valid as Melanorivulus faucireticulatus (Costa 2008) -- (Costa 2011:241 [ref. 31655] with date as 2007, Nielsen et al. 2016:87 [ref. 34407], Volcan et al. 2017:92 [ref. 35156], Costa 2018:25 [ref. 35717], Volcan et al. 2018:275 [ref. 35895]). Current status: Valid as Melanorivulus faucireticulatus (Costa 2008). Rivulidae: Rivulinae. Distribution: Bonfim River floodplains, Paraná River basin, Brazil. Habitat: freshwater.

feltrini, Cynopoecilus Costa [W. J. E. M.], Amorim [P. F.] & Mattos [J. L. O.] 2016:7, Figs. 1-2 [Biodiversity Data Journal 4.e6888; ref. 34354] Temporary pool near the confluence of Tubarão river and the Santo Antônio lagoon, Laguna, Santa Catarina, Brazil, 28°30'26"S, 48°48'01"W, depth 5 meters. Holotype: UFRJ 10662. Paratypes: UFRJ. •Valid as Cynopoecilus feltrini Costa, Amorim & Mattos 2016 -- (Costa 2016:130 [ref. 34776], Garcez et al. 2020:[3] [ref. 37602]). Current status: Valid as Cynopoecilus feltrini Costa, Amorim & Mattos 2016. Rivulidae: Cynolebiinae. Distribution: South America: Santa Catarina state (Brazil). Habitat: freshwater.

filamentosus, Plesiolebias Costa [W. J. E. M.] & Brasil [G. C.] in Costa 2007:27 [Zootaxa No. 1410; ref. 28993] Sampaio, temporary pool in rio Tocantins floodplains, about 1.5 kilometers from left river bank, 5°16'58"S, 47°53'30"W, Estado do Tocantins, Brazil, elevation 102 meters. Holotype: UFRJ 6367. Paratypes: UFRJ 5135 (13), 6368 (3, c&s), 4089 (11). Second author is G. C. Brasil. •Valid as Plesiolebias filamentosus Costa & Brasil 2007. Current status: Valid as Plesiolebias filamentosus Costa & Brasil 2007. Rivulidae: Rivulinae. Distribution: Temporary pools, middle Tocantins River floodplains, between Itaguatins and Sampaio, Estado do Tocantins, Brazil. Habitat: freshwater.

filamentosus, Simpsonichthys Costa [W. J. E. M.], Barrera [S.] & Sarmiento [J.] 1997:84, Figs. 1-2 [Revue française d'Aquariologie Herpétologie v. 24 (no. 3/4); ref. 23467] Swamp near Rio San Pablo, Rio Mamoré basin, about 15°37'S, 63°35'W, about 60 kilometers north of Ascencion de Guarayos, route Santa Cruz-Trinidad, Depto. de Santa Cruz, Bolivia. Holotype: CBF 3002. Paratypes: CBF 3003 (7), MZUSP 51328 (2), UFRJ 3989 (4). •Valid as Simpsonichthys filamentosus Costa, Barrera & Sarmiento 1997. •Valid as Spectrolebias filamentosus (Costa, Barrera & Sarmiento 1997) -- (Nielsen 2013:81 [ref. 32696], Nielsen & Brousseau 2013:121 [ref. 32794], Sarmiento et al. 2014:187 [ref. 35004], Drawert 2023:15 [ref. 40730]). Current status: Valid as Spectrolebias filamentosus (Costa, Barrera & Sarmiento 1997). Rivulidae: Cynolebiinae. Distribution: South America: Mamoré River and Beni River drainages, Madeira River basin (Bolivia). Habitat: freshwater.

flabellicauda, Rivulus Regan [C. T.] 1907:64 [Annals and Magazine of Natural History (Series 7) v. 19 (no. 109) (art. 6); ref. 15174] Juan Veñas, Costa Rica, elevation 1100 meters. Holotype (unique): BMNH 1907.6.28.37. •Synonym of Rivulus isthmensis Garman 1895 -- (Bussing 1980:330 [ref. 8732], Huber 1992:199 [ref. 20639]). •Synonym of Rivulus isthmensis Garman 1895, subspecies isthmensis Garman 1895 -- (Lazara 2001:277 [ref. 25711]). •Synonym of Cynodonichthys isthmensis (Garman 1895). Current status: Synonym of Cynodonichthys isthmensis (Garman 1895). Rivulidae: Rivulinae. Habitat: freshwater.

flagellatus, Simpsonichthys Costa [W. J. E. M.] 2003:46, Fig. 8 [Ichthyological Exploration of Freshwaters v. 14 (no. 1); ref. 26758] Temporary pool 12 kilometers west of Bom Jesus da Lapa, 13°15'43.2"S, 43°31'37.2"W, Bahia State, Brazil, elevation 449 meters. Holotype: MCP 28578. Paratypes: MCP 28579 (5); UFRJ 4788 (54), 4881 (10, 5 c&s). •Valid as Simpsonichthys flagellatus Costa 2003 -- (Costa 2006:26 [ref. 28771], Costa 2006:17 [ref. 28620], Costa 2007:110 [ref. 29445]). •Valid as Hypsolebias flagellatus (Costa 2003) -- (Costa & Amorim 2011:99 [ref. 31380], Costa 2011:222 [ref. 31654], Costa et al. 2012:72, 87 [ref. 31845], Costa et al. 2013:1 [ref. 32952], Britzke et al. 2016:134 [ref. 34461], Silva et al. 2020:14 [ref. 37809]). Current status: Valid as Hypsolebias flagellatus (Costa 2003). Rivulidae: Cynolebiinae. Distribution: South America: middle São Fancisco River basin (Minas Gerais and Bahia, Brazil) [but is a complex of several species [ref. 31845]]. Habitat: freshwater.

flammaecauda, Rivulus Vermeulen [F. B. M.] & Mejia-Vargas [D. A.] 2020:30, Figs. 6-10 [Killi-Data Series 2020; ref. 37938] Small creek and surroundings about 10 minutes' walk south-southwest in the forest starting where airstrip ends, La Guadalupe, Alto Rio Negro, Departamento Guainía, Colombia, 1°13'58.46"N, 66°52'41.78"W, elevation 106 meters. Holotype: IAVHP 13658. Paratypes: IAVHP 13659 (9). •Valid as Laimosemion flammaecauda (Vermeulen & Mejia-Vargas 2020). Current status: Valid as Laimosemion flammaecauda (Vermeulen & Mejia-Vargas 2020). Rivulidae: Rivulinae. Distribution: South America: Alto Rio Negro, Colombia, near border with Venezuela and Brazil. Habitat: freshwater.

flammeus, Cynolebias Costa [W. J. E. M.] 1989:185, Fig. 1 [Comunicações do Museu de Ciências da PUCRS, Série Zoologia v. 2 (no. 9); ref. 14323] Marsh at junction of Rio Bezerra and Rio Paraná, Arraias, Tocantins, Brazil [ca. 13°10'S, 47°00'W, elevation about 450 meters]. Holotype: MNRJ 11552. Paratypes: MCP 12795 (2), MNRJ 11553 (3). •Valid as Cynolebias flammeus Costa 1989 -- (Costa 1995:51 [ref. 22097]). •Valid as Simpsonichthys flammeus (Costa 1989) -- (Costa 1996:130 [ref. 25271], Costa 1998:75 [ref. 23792], Lazara 2001:297 [ref. 25711], Costa in Reis et al. 2003:541 [ref. 27061], Costa 2006:17 [ref. 28620], Costa 2007:128 [ref. 29445], Costa 2008:156 [ref. 29874]). •Valid as Hypsolebias flammeus (Costa 1989) -- (based on generic placement in Costa 2011 [ref. 31654], Nielsen et al. 2012:70 [ref. 32283], Nielsen et al. 2014:28 [ref. 33143], Nielsen et al. 2014:132 [ref. 33451]). Current status: Valid as Hypsolebias flammeus (Costa 1989). Rivulidae: Cynolebiinae. Distribution: Middle Tocantins River basin, Tocantins, central Brazil. Habitat: freshwater.

flava, Rivulus poeyi var. Brind [W. L.] 1915:40, Fig. [Domesticated fish; ref. 21099] No locality. •Synonym of Rivulus urophthalmus Günther 1866 -- (Lazara 2001:285 [ref. 25711]). •Synonym of Anablepsoides urophthalmus (Günther 1866). Current status: Synonym of Anablepsoides urophthalmus (Günther 1866). Rivulidae: Rivulinae. Habitat: freshwater.

flavicaudatus, Cynolebias Costa [W. J. E. M.] & Brasil [G. C.] 1990:18, Figs. 4-5 [Ichthyological Exploration of Freshwaters v. 1 (no. 1); ref. 14543] Vicinity of Lagoa Grande, County of Santa Maria da Boa Vista, Pernambuco, Brazil, about 9°00'S, 40°20'W, elevation 300 meters. Holotype: MZUSP 40129. Paratypes: MHNM 3252 (1), MNRJ 11556 (1), MZUSP 40130 (1). •Valid as Cynolebias flavicaudus Costa & Brasil 1990 -- (Costa 1995:55 [ref. 22097]). •Valid as Simpsonichthys flavicaudatus (Costa & Brasil 1990) -- (Costa et al. 1996:19 [ref. 22219], Costa 1996:130 [ref. 25271], Costa 1998:75 [ref. 23792], Lazara 2001:297 [ref. 25711], Costa 2003:44 [ref. 26768], Costa in Reis et al. 2003:541 [ref. 27061], Costa 2006:26 [ref. 28771], Costa 2006:17 [ref. 28620], Costa 2007:108 [ref. 29445], Endruweit 2009:61 [ref. 30288]). •Valid as Hypsolebias flavicaudatus (Costa & Brasil 1990) -- (Costa & Amorim 2011:99 [ref. 31380], Costa 2011:222 [ref. 31654], Costa et al. 2012:72 [ref. 31845], Costa et al. 2012:72, 77 [ref. 31845], Costa et al. 2013:1 [ref. 32952], Britzke et al. 2016:134 [ref. 34461], Loureiro et al. 2018:11 [ref. 36240]). Current status: Valid as Hypsolebias flavicaudatus (Costa & Brasil 1990). Rivulidae: Cynolebiinae. Distribution: Middle São Francisco River basin, Pernambuco, northeastern Brazil. Habitat: freshwater.

flavipinnis, Melanorivulus Costa [W. J. E. M.] 2017:57, Figs. 4-5 [ZooKeys No. 645; ref. 35046] Stream tributary of Rio Anhumas, Rio São Lourenço drainage, Rio Paraguai basin, Rondonópolis municipality, Mato Grosso state, Brazil, 16°48'16"S, 54°40'52"W, elevation approximately 420 meters. Holotype: UFRJ 6881. Paratypes: CICCAA, UFRJ. •Valid as Melanorivulus flavipinnis Costa 2017 -- (Deprá et al. 2017:121 [ref. 35503]). Current status: Valid as Melanorivulus flavipinnis Costa 2017. Rivulidae: Rivulinae. Distribution: Rio São Lourenço drainage, Rio Paraguai basin, Mato Grosso, Brazil. Habitat: freshwater.

fluminensis, Cynopoecilus Faria [A.] & Muller [H.] 1937:99 [Revista Naval No. 3; ref. 19184] Rio de Janeiro State, Brazil. Suppressed for purposes of priority but not homonymy; placed on Official Index (Opinion 1762); same as Cynolebias opalescens Myers 1942. •Valid as Cynolebias fluminensis (Faria & Muller 1937) -- (Costa & Lacerda 1988:132 [ref. 19183]). •Valid as Leptolebias fluminensis (Faria & Muller 1937) -- (Costa 1995:91 [ref. 22097], Costa 1998:73 [ref. 23792]). •Synonym of Leptolebias opalescens (Myers 1942) -- (Lazara 2001:194 [ref. 25711], Costa in Reis et al. 2003:531 [ref. 27061], Costa 2008:154 [ref. 29596]). •Synonym of Leptopanchax opalescens (Myers 1942). Suppressed. Current status: Synonym of Leptopanchax opalescens (Myers 1942). Rivulidae: Cynolebiinae. Habitat: freshwater.

foerschi, Cynolebias Baker-Carr [C. D. T.] 1975 [The Killifish master index. First edition; ref. 25877] Original not seen. •Nomen nudum in the synonymy of Leptolebias marmoratus (Ladiges 1934) -- (Lazara 2000:194 [ref. 25711]). Nomen Nudum. Current status: Synonym of Leptolebias marmoratus (Ladiges 1934). Rivulidae: Cynolebiinae.

foliiscola, Rivulus Vermeulen [F. B. M.] & Mejia-Vargas [D. A.] 2020:12, Figs. 1-5 [Killi-Data Series 2020; ref. 37935] Sinkhole in the secondary forest near the village La Guadalupe, Departamento Guainía, Colombia, 1°14'40.56"N, 66°51'57.47"W, elevation 82 meters. Holotype: IAVHP 13652. Paratypes: IAVHP 13653 (7). •Valid as Laimosemion foliiscola (Vermeulen & Mejia-Vargas 2020). Current status: Valid as Laimosemion foliiscola (Vermeulen & Mejia-Vargas 2020). Rivulidae: Rivulinae. Distribution: South America: La Guadalupe, Departamento Guainía, Colombia, near border with Venezuela and Brazil. Habitat: freshwater.

formosa, Maratecoara Costa [W. J. E. M.] & Brasil [G. C.] in Costa 1995:69, Figs. 5-7 [Revue française d'Aquariologie Herpétologie v. 21 (no. 3/4) [for 1994]; ref. 21612] Temporary pool in Brejinho de Nazaré, Estado do Tocantins, Brazil, about 10°59'S, 48°38'W. Holotype: MNRJ 12521. Paratypes: MNRJ 12522 (2); MZUSP 46081 (2); UFRJ 2111 (4, 2 c&s), 2112 (4). Second author is G. C. Brasil. •Valid as Maratecoara formosa Costa & Brasil 1995 -- (Costa 1998:82 [ref. 23792], Lazara 2001:201 [ref. 25711], Costa 2007:34 [ref. 28993], Nielsen et al. 2014:90 [ref. 33275]). Current status: Valid as Maratecoara formosa Costa & Brasil 1995. Rivulidae: Rivulinae. Distribution: Seasonal lagoons in middle Tocantins River floodplains, Estado do Tocantins, Brazil. Habitat: freshwater.

formosensis, Rivulus Costa [W. J. E. M.] 2008:86, Figs. 1-2 [Ichthyological Exploration of Freshwaters v. 19 (no. 1); ref. 29717] Formoso River floodplains near Santa Amélia farm, upper Corrente River drainage, a part of the Paranaíba River drainage, Município de Chapadão do Céu, Estado de Goiás, Brazil. Holotype: UFRJ 6543. Paratypes: UFRJ 6544 (9), 6545 (4, 2 c&s), 5387 (2). •Valid as Melanorivulus formosensis (Costa 2008) -- (Nielsen et al. 2016:87 [ref. 34407], Volcan et al. 2017:92 [ref. 35156], Costa 2018:25 [ref. 35717], Volcan et al. 2018:275 [ref. 35895]). Current status: Valid as Melanorivulus formosensis (Costa 2008). Rivulidae: Rivulinae. Distribution: Formoso River floodplains, upper Corrente River drainage, upper Paraná River basin, central Brazil. Habitat: freshwater.

fractifasciatus, Cynolebias Costa [W. J. E. M.] 1988:562, Figs. 2, 4d-4f [Revista Brasileira de Zoologia v. 5 (no. 4); ref. 14540] Marsh near Inoã, Maricá, Rio de Janeiro, Brazil. Holotype: MZUSP 36423. Paratypes: MNRJ 11292 (2), MZUSP 36424 (11), personal coll. of Prof. Carlos A.G. Cruz CAGC 123 (19). •Synonym of Leptolebias minimus (Myers 1942) -- (Costa 1995:89 [ref. 22097], Lazara 2001:194 [ref. 25711]). •Valid as Leptolebias fractifasciatus (Costa 1988) -- (Costa 1998:73 [ref. 23792], Costa in Reis et al. 2003:530 [ref. 27061]). •Valid as Notholebias fractifasciatus (Costa 1988) -- (Costa 2008:157 [ref. 29596], Costa & Amorim 2013:67 [ref. 32799], Ferrer et al. 2014:847 [ref. 33589], Costa et al. 2016:3 [ref. 34354], Costa 2016:128 [ref. 34776]). Current status: Valid as Notholebias fractifasciatus (Costa 1988). Rivulidae: Cynolebiinae. Distribution: Atlantic coastal river basins, southeastern Brazil. Habitat: freshwater.

fragilis, Plesiolebias Costa [W. J. E. M.] 2007:21, Figs. 14-15 [Zootaxa No. 1410; ref. 28993] Temporary pool in left rio Formoso floodplains, rio Javaés drainage, rio Araguaia basin, road BR-242, between Formoso do Araguaia and São João do Havaés, 11°47'31.6"S, 49°45'54.7"W, Estado do Tocantins, Brazil. Holotype: UFRJ 6411. Paratypes: MCP 40499 (2); UFRJ 3793 (24), 5049 (8, c&s), 5262 (4), 6412 (2). •Valid as Plesiolebias fragilis Costa 2007. Current status: Valid as Plesiolebias fragilis Costa 2007. Rivulidae: Rivulinae. Distribution: Seasonal swamps of the middle Araguaia basin, Estado do Tocantins, Brazil. Habitat: freshwater.

francescae, Papiliolebias Valdesalici [S.] & Brousseau [R.] 2014:117, Figs. 1-2 [aqua, International Journal of Ichthyology v. 20 (no. 3); ref. 33449] Departamento Santa Cruz, Ñuflo de Chávez Province, south of San Ramon, seasonal pools in the Rio San Pablo drainage, Rio Madeira River basin, 16°39’47"S, 62°31’19"W, Bolivia, altitude 240 meters. Holotype: MSNG 57820. Paratypes: MSNG 57801 (9, 1 c&s). •Valid as Papiliolebias francescae Valdesalici & Brousseau 2014 -- (Valdesalici et al. 2016:162 [ref. 34860], Drawert 2023:26 [ref. 40730]). Current status: Valid as Papiliolebias francescae Valdesalici & Brousseau 2014. Rivulidae: Rivulinae. Distribution: South America: Rio San Pablo drainage (Bolivia). Habitat: freshwater.

fransvermeuleni, Anablepsoides Valdesalici [S.] 2015:242, Figs. 1-2 [Ichthyological Exploration of Freshwaters v. 26 (no. 3); ref. 34049] Upper Nickerie River drainage, western Suriname, 4°50'42"N, 56°50'54"W, elevation 130 meters. Holotype: NZCS F7092. Paratypes: RMNH ZMA. •Valid as Rivulus fransvermeuleni (Valdesalici 2015) -- (Vermeulen 2020:45 [ref. 37941]). •Valid as Anablepsoides fransvermeuleni Valdesalici 2015. Current status: Valid as Anablepsoides fransvermeuleni Valdesalici 2015. Rivulidae: Rivulinae. Distribution: Upper Nickerie drainage, western Suriname. Habitat: freshwater.

fransvermeuleni, Rachovia Berkenkamp [H. O.] 2020:4, Figs. 3-4 [Wissenschaftliche Publikationen aus dem Referat Fischbestimmung des VDA-Bezirks 25, Weser-Ems, Verband Deutscher Vereine für Aquarien- und Terrarienkunde e V. 2020 (no. 12); ref. 37695] 21 km to the north from Los Pijiguaos to Caicara, on the right side of the road from Puerto Ayacucho to Caicara, Estado Bolivar, southwest Venezuela, 06°43'25.96"N, 66°43'52.96"W. Holotype: SMF 18304. Paratypes: SMF 18305 (5). •Valid as Rachovia fransvermeuleni Berkenkamp 2020. Current status: Valid as Rachovia fransvermeuleni Berkenkamp 2020. Rivulidae: Rivulinae. Distribution: Floodplains in the eastern Orinoco basin, Estado Bolivar, southwest Venezuela. Habitat: freshwater.

frenatus, Rivulus Eigenmann [C. H.] 1912:453, 455 [Memoirs of the Carnegie Museum v. 5 (no. 1); ref. 1227] Essequibo River at Gluck Island, Guyana. Holotype (unique): FMNH 53538 [ex CM 1085]. Type catalog: Henn 1928:86 [ref. 12305], Ibarra & Stewart 1987:76 [ref. 12367]. Available from key on p. 453. Name used previously in Eigenmann 1909:51 [ref. 1222] and Eigenmann 1910 [ref. 1224] with reference to type and locality, but without diagnostic characters and therefore not available from either of those publications (Art. 12.1 of the Code). Combined with a neuter genus, the adjective should be frenatum. •Valid as Rivulus frenatus Eigenmann 1912 -- (Huber 1992:202 [ref. 20639], Lazara 2001:274 [ref. 25711], Costa in Reis et al. 2003:536 [ref. 27061], Suijker & Collier 2006:10 [ref. 28729], Costa 2006:153 [ref. 28875] in subgenus Laimosemion). •Valid as Laimosemion frenatum (Eigenmann 1912) -- (Costa 2011:239 [ref. 31655] as frenatus, Vermeulen et al. 2012:188 [ref. 32253] as frenatus, Taphorn et al. 2022:36 [ref. 41297]). Current status: Valid as Laimosemion frenatum (Eigenmann 1912). Rivulidae: Rivulinae. Distribution: South America: Essequibo River basin (Guyana and Suriname) endemic. Habitat: freshwater.

frommi, Rivulus Berkenkamp [H. O.] & Etzel [V.] 1993:81, Figs. [Deutsche Killifisch Gemeinschaft Journal v. 25 (no. 6); ref. 21583] Coclé Province, north of El Valle, central Panama, 8°58'N, 80°22'W. Holotype: SMF 18441. Paratypes: SMF 18442-44 (1, 5, 3). •Valid as Rivulus frommi Berkenkamp & Etzel 1993 -- (Lazara 2001:275 [ref. 25711], Costa in Reis et al. 2003:536 [ref. 27061] Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys). •Valid as Cynodonichthys frommi (Berkenkamp & Etzel 1993) -- (Costa 2011:242 [ref. 31655]). Current status: Valid as Cynodonichthys frommi (Berkenkamp & Etzel 1993). Rivulidae: Rivulinae. Distribution: Pacific river basins, Panama. Habitat: freshwater.

fulgens, Cynopoecilus Costa [W. J. E. M.] 2002:16, Fig. 3 [Ichthyological Exploration of Freshwaters v. 13 (no. 1); ref. 26061] Temporary pool, road BR-101, 5 kilometers north of São José do Norte, about 32°00'S, 52°00'W, Rio Grande do Sul, Brazil. Holotype: MCP 26929. Paratypes: MCP 26930 (5); UFRJ 4978 (9), 5230 (5, 4 c&s). •Valid as Cynopoecilus fulgens Costa 2002 -- (Costa in Reis et al. 2003:530 [ref. 27061], Ferrer et al. 2014:847 [ref. 33589], Costa et al. 2016:4 [ref. 34354], Bertaco et al. 2016:424 [ref. 34561], Costa 2016:130 [ref. 34776], Dalcin & Abilhoa 2019:680 [ref. 37274], Garcez et al. 2020:[3] [ref. 37602]). Current status: Valid as Cynopoecilus fulgens Costa 2002. Rivulidae: Cynolebiinae. Distribution: South America: Atlantic coastal plains of northern Rio Grande do Sul and southern Santa Catarina (Brazil). Habitat: freshwater.

fulminantis, Cynolebias Costa [W. J. E. M.] & Brasil [G. C.] 1993:194, Figs. 1-2 [Ichthyological Exploration of Freshwaters v. 4 (no. 3); ref. 21101] Swamp near Guanambi [14°15'15.6"S, 42°46'55.6"W, elevation 555 meters], Estado da Bahia, Brazil. Holotype: MZUSP 43674. Paratypes: MZUSP 43675 (2); UFRJ 685 (2), 686 (3). •Synonym of Cynolebias hellneri Berkenkamp 1993 -- (Costa 1995:125 [ref. 22097]). •Valid as Simpsonichthys fulminantis (Costa & Brasil 1993) -- (Costa 1996:130 [ref. 25271], Costa 1998:75 [ref. 23792], Lazara 2001:297 [ref. 25711], Costa in Reis et al. 2003:541 [ref. 27061], Costa & Nielsen 2004:126 [ref. 27825], Costa & Nielsen 2004:126 [ref. 27825], Costa 2006:17 [ref. 28620], Costa 2007:87 [ref. 29445]). •Valid as Hypsolebias fulminantis (Costa & Brasil 1993) -- (based on generic placement in Costa 2011 [ref. 31654], Nielsen et al. 2014:28 [ref. 33143], Nielsen et al. 2014:132 [ref. 33451], Costa et al. 2018:501 [ref. 36319], Silva et al. 2020:14 [ref. 37809]). Current status: Valid as Hypsolebias fulminantis (Costa & Brasil 1993). Rivulidae: Cynolebiinae. Distribution: South America: upper Carnaiba de Dentro River drainage, São Francisco River basin (Bahia State, Brazil). Habitat: freshwater.

funkneri, Moema Valdesalici [S.] 2019:104, Figs. 1-3 [aqua, International Journal of Ichthyology v. 25 (no. 3); ref. 36959] Seasonal pool in the Río Grande drainage, Río Mamoré basin, Departamento Santa Cruz, Provincia Chiquitos, Bolivia, 17°42'21.0"S, 62°43'42.0"W. Holotype: MSNG 61241. Paratypes: MSNG 61242 (5). •Valid as Moema funkneri Valdesalici 2019 -- (Drawert 2022:13 [ref. 39805], Drawert 2023:32 [ref. 40730]). Current status: Valid as Moema funkneri Valdesalici 2019. Rivulidae: Rivulinae. Distribution: South America: Río Grande drainage, Río Mamoré basin (Bolivia). Habitat: freshwater.

fuscolineatus, Rivulus Bussing [W. A.] 1980:336, Figs. 1A, 5A, 6A [Brenesia No. 17; ref. 8732] Quebrada Santa Fe, 6.1 kilometers north of Tilaran on road to Aguacate, Guanacaste Province, Costa Rica, elevation 640 meters. Holotype: LACM 38276-1. Paratypes: LACM 2754 (8), 38276-2 (20); UCR 28-3 (5), 30-9 (2), 899-2 (161 or 162), 900-2 (2), 945-10 (1), 949-3 (4), 953-11 (53), 956-1 (4), 960-2 (10), 964-4 (1); USNM 219778 (10). Type catalog: Angulo et al. 2015:372 [ref. 35212]. •Valid as Rivulus fuscolineatus Bussing 1980 -- (Bussing 1987:119 [ref. 22927], Huber 1992:205 [ref. 20639], Bussing 1998:171 [ref. 24179], Lazara 2001:275 [ref. 25711], Costa in Reis et al. 2003:536 [ref. 27061], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys). •Valid as Cynodonichthys fuscolineatus (Bussing 1980) -- (Costa 2011:242 [ref. 31655], Angulo et al. 2013:995 [ref. 33194], Angulo 2021:13 [ref. 38913]). Current status: Valid as Cynodonichthys fuscolineatus (Bussing 1980). Rivulidae: Rivulinae. Distribution: Central America: Atlantic slope (Costa Rica). Habitat: freshwater.

gamae, Anablepsoides Costa [W. J. E. M.], Bragança [P. H. N.] & Amorim [P. F.] 2013:290, Figs. 4c, 6 [Vertebrate Zoology v. 63 (no. 3); ref. 33108] Estado do Amapá: Município de Laranjal do Jari: stream tributary to Jari river, between Laranjal do Jari and Santo Antônio waterfall, Amazonas river basin, 0°45’55"S, 52°31’17"W, Brazil. Holotype: UFRJ 9606. Paratypes: IEPA 2755 (1); UFRJ 8840 (5), 8841 (4), 9607 (3 c&s) •Valid as Anablepsoides gamae Costa, Bragança & Amorim 2013 -- (Nielsen & Veiga 2021:10 [ref. 38269]). Current status: Valid as Anablepsoides gamae Costa, Bragança & Amorim 2013. Rivulidae: Rivulinae. Distribution: Lower Jari River basin, Amapá, Brazil. Habitat: freshwater.

garciai, Rivulus de la Cruz [J.] & Dubitsky [A. M.] 1976:4 [Poeyana, Series A, Instituto de Biologia No. 155; ref. 7324] Matanzas, Varadero, Cuba. Holotype (unique): IZAC uncat. Costa in Reis et al. 2003:536 [ref. 27061] gives a lectotype as IZAC uncat. •Synonym of Rivulus marmoratus Poey 1880 -- (Huber 1992:209 [ref. 20639], Lazara 2001:280 [ref. 25711]). •Valid as Rivulus garciai de la Cruz & Dubitsky 1976 -- (Lee et al. 1983:58 [ref. 22527], Costa in Reis et al. 2003:536 [ref. 27061]). •Possibly valid, in Cryptolebias -- (Costa 2004:115 [ref. 27763]). •Possilby valid in Kryptolebias -- (Costa 2004:107 [ref. 28584]). •Synonym of Kryptolebias marmoratus (Poey 1880) -- (Costa 2006:6 [ref. 28624], Costa 2016:189 [ref. 34932], Faloh-Gandarilla et al. 2016:7 [ref. 35177] as garciae). Current status: Synonym of Kryptolebias marmoratus (Poey 1880). Rivulidae: Kryptolebiatinae. Habitat: freshwater, brackish.

gardneri, Hypsolebias Costa [W. J. E. M.], Amorim [P. F.] & Mattos [J. L. O.] 2018:146, Figs. 2, 5B [ZooKeys No. 777; ref. 36034] Temporary pool near road BR-030, about 8 km NE of the village of Malhada, São Francisco River floodplains, Malhada municipality, Bahia State, Brazil, 14°17'39"S, 43°42'32"W, elevation about 440 meters. Holotype: UFRJ 11859. Paratypes: CICCAA, UFRJ. •Valid as Hypsolebias gardneri Costa, Amorim & Mattos 2018 -- (Silva et al. 2020:14 [ref. 37809]). Current status: Valid as Hypsolebias gardneri Costa, Amorim & Mattos 2018. Rivulidae: Cynolebiinae. Distribution: South America: middle São Francisco River basin (Brazil). Habitat: freshwater.

gaucheri, Rivulus Keith [P.], Nandrin [L.] & Le Bail [P.-Y.] 2006:134, Fig. 2 [Cybium v. 30 (no. 2); ref. 28851] Mitaraka, marshes in Alama River (Litany basin), French Guiana, 2°17.295'N, 54°32.665"W, elevation 339 meters. Holotype: MNHN 2005-0171. Paratypes: MNHN 2002-0084 (2), 2002-0202 (1), 2002-3540 (7). Plus non-type material. •Valid as Anablepsoides gaucheri (Keith, Nandrin & Le Bail 2006) -- (Costa 2011:243 [ref. 31655], Brosse et al. 2019:134 [ref. 38320]). Current status: Valid as Anablepsoides gaucheri (Keith, Nandrin & Le Bail 2006). Rivulidae: Rivulinae. Distribution: Northern South America: upper Maroni basin (French Guiana). Habitat: freshwater.

geayi, Rivulus Vaillant [L. L.] 1899:156 [3] [Bulletin du Muséum d'Histoire Naturelle, Paris (sér. 1) v. 5 (no. 4); ref. 14710] Carsevenne River, French Guiana, elevation 450 meters. Lectotype: MNHN 1899-0101. Paralectotypes: BMNH 1899.7.26.6-10 [ex MNHN] (5); MNHN 1899-0100 (5), 1899-0101 (4), 1899-0103 (5 or 6). Type catalog: Bertin & Estève 1950:28 [ref. 19576]. Type information: Huber 1992 [ref. 20639]. On p. 3 of separate. Lectotype selected in Huber 1992:211 [ref. 20639]. •Valid as Rivulus geayi Vaillant 1899 -- (Huber 1991:70 [ref. 19721], Huber 1992:211 [ref. 20639], Huber 1999:50 [ref. 23834], Keith et al. 2000:40 [ref. 24547], Lazara 2001:275 [ref. 25711], Costa in Reis et al. 2003:536 [ref. 27061], Hrbek et al. 2004:569 [ref. 27910], Vermeulen & Hrbek 2005:7 [ref. 28142], Suijker & Collier 2006:10 [ref. 28729], Keith et al. 2006:137 [ref. 28851], Costa 2006:153 [ref. 28875] in subgenus Laimosemion). •Valid as Laimosemion geayi (Vaillant 1899) -- (Costa 2011:239 [ref. 31655], Vermeulen et al. 2012:188 [ref. 32253], Valdesalici & García Gil 2015:169 [ref. 34010], Brosse et al. 2019:134 [ref. 38320]). Current status: Valid as Laimosemion geayi (Vaillant 1899). Rivulidae: Rivulinae. Distribution: South America: Atlantic coastal river drainages and Amazon River basin (Brazil and French Guiana). Habitat: freshwater.

gesmonei, Maratecoara Nielsen [D. T. B.], Martins [M.] & Britzke [R.] 2014:87, Figs. 1-2 [aqua, International Journal of Ichthyology v. 20 (no. 2); ref. 33275] Pará state, São Félix do Xingu, temporary pool at island in the middle of the rio Xingu, 6°39’33.3’’S ,52°00’21.9’’ W, Brazil., Holotype: ZUEC 7851. Paratypes: LBP 18387 (10), ZUEC 7852 (2, c&s). •Valid as Maratecoara gesmonei Nielsen, Martins & Britzke 2014. Current status: Valid as Maratecoara gesmonei Nielsen, Martins & Britzke 2014. Rivulidae: Rivulinae. Distribution: Rio Xingu system, Pará State, Brazil. Habitat: freshwater.

ghisolfii, Simpsonichthys Costa [W. J. E. M.], Cyrino [A. L. F.] & Nielsen [D. T. B.] 1996:18, Figs. 1-3 [Revue française d'Aquariologie Herpétologie v. 23 (no. 1/2); ref. 22219] Guanambí, 14°15'15.6"S, 42°46'55.6"W, Bahia, Brazil, elevation 555 meters. Holotype: MZUSP 49403. Paratypes: MZUSP 49404 (1); UFRJ 3526-27 (2, 2). •Valid as Simpsonichthys ghisolfii Costa, Cyrino & Nielsen 1996 -- (Costa 1998:75 [ref. 23792], Lazara 2001:297 [ref. 25711], Costa 2003:41 [ref. 26768], Costa in Reis et al. 2003:541 [ref. 27061], Costa 2006:26 [ref. 28771], Costa 2006:17 [ref. 28620], Costa 2007:104 [ref. 29445]). •Valid as Hypsolebias ghisolfii (Costa, Cyrino & Nielsen 1996) -- (Costa 2011:222 [ref. 31654], Costa et al. 2013:1 [ref. 32952], Nielsen et al. 2014:28 [ref. 33143] aas ghrisolfi, Britzke et al. 2016:134 [ref. 34461], Silva et al. 2020:14 [ref. 37809]). Current status: Valid as Hypsolebias ghisolfii (Costa, Cyrino & Nielsen 1996). Rivulidae: Cynolebiinae. Distribution: South America: Rio das Rãs drainage, São Francisco River basin (Bahia State, Brazil). Habitat: freshwater.

giarettai, Rivulus Costa [W. J. E. M.] 2008:92, Figs. 1-2 [Ichthyological Exploration of Freshwaters v. 19 (no. 1); ref. 29718] Stream ributary to Araguari River crossing road between Uberaba and Nova Ponte, Municápio de Nova Ponte, Paranaíba River drainage, upper Paraná River, 19°19'51"S, 47°44'07"W, Estado de Minas Gerais, Brazil, elevation 946 meters. Holotype: UFRJ 6488. Paratypes: UFRJ 6489 (2), 6490 (18), 6491 (4), 6492 (8), 6493 (4), 5402 (24). •Valid as Melanorivulus giarettai (Costa 2008) -- (Costa 2011:241 [ref. 31655], Nielsen et al. 2016:87 [ref. 34407], Volcan et al. 2017:92 [ref. 35156], Volcan et al. 2018:275 [ref. 35895]). Current status: Valid as Melanorivulus giarettai (Costa 2008). Rivulidae: Rivulinae. Distribution: Middle Araguari River drainage, upper Paraná River basin, Brazil. Habitat: freshwater.

gibberatus, Simpsonichthys Costa [W. J. E. M.] & Brasil [G. C.] 2006:50, Figs. 6-7 [Zootaxa No. 1244; ref. 28725] Temporary pool about 2 kilometers from right bank of rio Preto, rio Paracatu drainage, rio São Francisco basin, about 16°41'30"S, 46°30'00"W, Unaí, Estado de Minas Gerais, Brazil, elevation about 550 meters. Holotype: UFRJ 6373. Paratypes: MCP 39437 (4); UFRJ 6374 (11), 6375 (6, c&s). •Valid as Hypsolebias gibberatus (Costa & Brasil 2006) -- (Costa 2010:1999 [ref. 30858], misspelled as gibbus). •Valid as Simpsonichthys gibberatus Costa & Brasil 2006 -- (Costa 2007:72 [ref. 29445]). •Valid as Hypsolebias gibberatus (Costa & Brasil 2006) -- (based on generic placement in Costa 2011 [ref. 31654]). Current status: Valid as Hypsolebias gibberatus (Costa & Brasil 2006). Rivulidae: Cynolebiinae. Distribution: Middle Preto River drainage, São Francisco River basin, Unaí, Minas Gerais State, Brazil. Habitat: freshwater.

gibberosus, Cynolebias Berg [C.] 1897:294 [Anales del Museo Nacional de Historia Natural de Buenos Aires v. 5; ref. 14623] Cacharí, Partido de Azul, Buenos Aires Province, Argentina. Lectotype: MACN 5172. Paralectotypes: MACN 5177 (1). Type catalog: Braga & Piacentino 1994:100 [ref. 23697]. Costa in Reis et al. 2003:527 [ref. 27061] treat MACN 5172 as holotype. Lectotype selected by Costa 2006:108 [ref. 28708]. •Synonym of Cynolebias bellottii Steindachner 1881 -- (Costa 1995:71 [ref. 22097]). •Synonym of Austrolebias bellotti (Steindachner 1881) -- (Lazara 2001:60 [ref. 25711], Costa in Reis et al. 2003:527 [ref. 27061]). •Synonym of Austrolebias bellottii (Streindachner 1881) -- (Costa 2006:104 [ref. 28708], Mirande & Koerber 2015:51 [ref. 35117]). Current status: Synonym of Austrolebias bellottii (Steindachner 1881). Rivulidae: Cynolebiinae. Habitat: freshwater.

gibbus, Cynolebias Costa [W. J. E. M.] 2001:378, Figs. 31-32 [Ichthyological Exploration of Freshwaters v. 12 (no. 4); ref. 25719] Temporary pool, 9.5 kilometers north of Sítio do Mato, about 13°00'S, 43°25'W, Bahia, Brazil. Holotype: MZUSP 62568. Paratypes: UFRJ 4796-97 (5, 2), 5027 (1), 5133 (2, c&s), 5134 (1, c&s); MZUSP 62569 (3). •Valid as Cynolebias gibbus Costa 2001 -- (Costa in Reis et al. 2003:529 [ref. 27061], Costa 2009:146 [ref. 30511], Costa 2014:80 [ref. 33510], Silva et al. 2020:13 [ref. 37809]). Current status: Valid as Cynolebias gibbus Costa 2001. Rivulidae: Cynolebiinae. Distribution: South America middle São Francisco River basin (Brazil). Habitat: freshwater.

gilbertobrasili, Hypsolebias Costa [W. J. E. M.] in Costa, Amorim & Mattos 2012:81, Figs. 6, 13 [Systematics and Biodiversity v. 10 (no. 1); ref. 31845] Seasonal swamp about 35 km south of the town of Bom Jesus da Lapa, road BA-090, middle São Francisco River basin, 13°34'49"S, 43°22'39"W, Estado da Bahia, Brazil, elevation 442 meters. Holotype: UFRJ 8325. Paratypes: BMNH 2011.11.1.7-8 (2); UFRJ 2195 (19), 3160 (4, c&s), 6800 (1). •Valid as Hypsolebias gilbertobrasili Costa 2012 -- (Costa et al. 2013:1 [ref. 32952], Britzke et al. 2016:134 [ref. 34461], Silva et al. 2020:14 [ref. 37809]). Current status: Valid as Hypsolebias gilbertobrasili Costa 2012. Rivulidae: Cynolebiinae. Distribution: South America: São Francisco River basin (Bahia State, Brazil). Habitat: freshwater.

gilbertoi, Cynolebias Costa [W. J. E. M.] 1998:238, Fig. 1 [Cybium v. 22 (no. 3); ref. 23578] Temporary pond about 30 kilometers south of Bom Jesus da Lapa, near rio São Francisco, Estado da Bahia, Brazil. Holotype: MZUSP 52304. Paratypes: MZUSP 52305 (1); UFRJ 4470 (3), 4471 (2, c&s). •Valid as Cynolebias gilbertoi Costa 1998 -- (Costa 1998:76 [ref. 23792], Lazara 2001:77 [ref. 25711], Costa 2001:364 [ref. 25719], Costa in Reis et al. 2003:529 [ref. 27061], Costa 2009:146 [ref. 30511], Costa 2014:79 [ref. 33510], Silva et al. 2020:13 [ref. 37809]). Current status: Valid as Cynolebias gilbertoi Costa 1998. Rivulidae: Cynolebiinae. Distribution: South America: middle São Francisco River basin (Brazil). Habitat: freshwater.

gili, Laimosemion Valdesalici [S.] & Nielsen [D. T. B.] 2017:98, Figs. 1-2 [aqua, International Journal of Ichthyology v. 23 (no. 3); ref. 35496] Creek Garukana, tributary of Rio Preto, Rio Negro basin, Santa Isabel do Rio Negro, Amazonas, Brazil, 0°6'31"S, 64°7'18"W, elevation 38 meters. Holotype: ZUEC 14575. Paratypes: MSNG, ZUEC. •Valid as Rivulus gili (Valdesalici & Nielsen 2017) -- (Vermeulen 2023:109 [ref. 40177]). •Valid as Laimosemion gili Valdesalici & Nielsen 2017. Current status: Valid as Laimosemion gili Valdesalici & Nielsen 2017. Rivulidae: Rivulinae. Distribution: Rio Preto drainage, Rio Negro basin, Amazonas, Brazil. Habitat: freshwater.

glaucopterus, Cynolebias Costa [W. J. E. M.] & Lacerda [M. T. C.] 1988:16 [Revista Aquariofilia v. 5; ref. 19792] Temporary pool near Rio Paraguai, Município de Cáceres, Mato Grosso, Brazil. Holotype: MZUSP 38533. Paratypes: MNRJ, MZUSP. Also described as new in Costa & Lacerda 1989 [ref. 19793]. •Valid as Plesiolebias glaucopterus (Costa & Lacerda 1988) -- (Costa 1991:375 [ref. 13611], Costa 1995:28 [ref. 22097], Costa 1998:322 [ref. 23324], Costa 1998:81 [ref. 23792], Britski et al. 1999:139 [ref. 24147], Costa & Le Bail 1999:1028 [ref. 24187], Lazara 2001:257 [ref. 25711], Costa in Reis et al. 2003:533 [ref. 27061]). Current status: Valid as Plesiolebias glaucopterus (Costa & Lacerda 1988). Rivulidae: Rivulinae. Distribution: South America: Paraguay River basin, Mato Grosso, Brazil. Habitat: freshwater.

glaucus, Rivulus Bussing [W. A.] 1980:342, Figs. 2D, 5D, 6D [Brenesia No. 17; ref. 8732] Tributary of Río Pedregoso at southern edge of San Isidro de El General, San José Province, Costa Rica, elevation 680 meters. Holotype: LACM 38277-1. Paratypes: LACM 38277-2 (5); UCR 42-7 (4), 300-3 (5), 519-7 (2), 592-1 (10), 750-2 (2), 1198-1 (6). Type catalog: Angulo et al. 2015:372 [ref. 35212]. •Valid as Rivulus glaucus Bussing 1980 -- (Bussing 1987:120 [ref. 22927], Huber 1992:215 [ref. 20639], Bussing 1998:173 [ref. 24179], Lazara 2001:275 [ref. 25711], Costa in Reis et al. 2003:536 [ref. 27061], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys). •Valid as Cynodonichthys glaucus (Bussing 1980) -- (Costa 2011:242 [ref. 31655], Angulo et al. 2013:995 [ref. 33194], Angulo et al. 2020:6 [ref. 37425]). Current status: Valid as Cynodonichthys glaucus (Bussing 1980). Rivulidae: Rivulinae. Distribution: Central America: Pacific slope of Costa Rica. Habitat: freshwater.

godmani, Rivulus Regan [C. T.] 1907:65 [Annals and Magazine of Natural History (Series 7) v. 19 (no. 109) (art. 6); ref. 15174] Guatemala. Lectotype: BMNH 1885.5.24.39-40 (female). Paralectotypes: BMNH 1885.5.24.39-40 (1). Originally as godmanni with collector as Godman. Emended by Regan 1907:81-83, Pl. 10 (fig. 5) [ref. 3629] to godmani, also spelled godmani by Regan 1912:499 [ref. 3648]. Lectotype selected in Huber 1992:218 [ref. 20639]. •Synonym of Rivulus tenuis (Meek 1904) -- (Huber 1992:218 [ref. 20639], Lazara 2001:285 [ref. 25711], Costa in Reis et al. 2003:539 [ref. 27061], Miller 2006:208 [ref. 28615]). •Valid as Cynodonichthys godmani (Regan 1907) -- (Costa 2011:242 [ref. 31655]). •Valid as Rivulus godmani Regan 1907 -- (Collier 2016:42 [ref. 35018]). Current status: Valid as Cynodonichthys godmani (Regan 1907). Rivulidae: Rivulinae. Distribution: Middle America: Guatemala and Mexico. Habitat: freshwater.

gomesi, Rivulus Huber [J. H.], Mejía-Vargas [D. A.] & Vermeulen [F. B. M.] 2023:83, Figs. 6-8 [Killi-Data Series 2023; ref. 40176] Ruta 62, 11 km south of Chigorodó, Antioquia Department, northwest Colombia, 7.574N, 76.624W, elevation 47 meters. Holotype: CIUA 7704. Paratypes: CIUA 7705 (4), MNHN 2022-0256 (5). Genus tentative. •Valid as Cynodonichthys gomesi (Huber, Mejía-Vargas & Vermeulen, 2023). Current status: Valid as Cynodonichthys gomesi (Huber, Mejía-Vargas & Vermeulen, 2023). Rivulidae: Rivulinae. Distribution: South America: Antioquia Department, northwest Colombia. Habitat: freshwater.

gongobira, Hypsolebias Abrantes [Y. G.], Ramos [T. P. A.], Bento [D. M.] & Lima [S. M. Q.] 2023:549, Figs. 2-3, 8A [Zootaxa 5389 (no. 5); ref. 40706] Temporary pool near Rio Pacoti, Aquiraz Municipality, Ceará State, Brazil, 03°53'48"S, 38°24'17"W. Holotype: MNRJ 54900. Paratypes: MZUSP, UFRN. •Valid as Hypsolebias gongobira Abrantes, Ramos, Bento & Lima 2023. Current status: Valid as Hypsolebias gongobira Abrantes, Ramos, Bento & Lima 2023. Rivulidae: Cynolebiinae. Distribution: South America: floodplains of the Rio Pacoti, Ceará State, Brazil. Habitat: freshwater.

gorutuba, Cynolebias Costa [W. J. E. M.] 2017:336, Figs. 3-4 [Zoosystematics and Evolution v. 93 (no. 2); ref. 35623] Temporary pool near road MG-401, floodplains of Gorutuba River, Verde Grande River drainage, São Francisco River basin, Janaúba municipality, Minas Gerais State, Brazil, 15°47'57"S, 43°19'18"W, elevation about 525 meters. Holotype: UFRJ 6789. Paratypes: UFRJ. •Valid as Cynolebias gorutuba Costa 2017. Current status: Valid as Cynolebias gorutuba Costa 2017. Rivulidae: Cynolebiinae. Distribution: Gorutuba River drainage, São Francisco River basin, Minas Gerais, Brazil. Habitat: freshwater.

gracilis, Kryptolebias Costa [W. J. E. M.] 2007:8, Figs. 1-2 [aqua, International Journal of Ichthyology v. 13 (no. 1); ref. 29397] Small black water creek adjacent to Rio Meto Grosso, Lagoa de Saquarema basin, Rio de Janeiro State, Brazil, approximately 22°53'S, 42036'W. Holotype: UFRJ 6450. Paratypes: (29) MCP 42222 (2); UFRJ 1689 (6), 6297 (9), 6345 (1 + 1 c&s), 6451 (10). •Valid as Kryptolebias gracilis Costa 2007. Current status: Valid as Kryptolebias gracilis Costa 2007. Rivulidae: Kryptolebiatinae. Distribution: Southeastern Brazil. Habitat: freshwater.

gracilis, Spectrolebias Costa [W. J. E. M.] & Amorim [P. F.] 2018:363, Figs. 4-5 [Zoosystematics and Evolution v. 94 (no. 2); ref. 36019] Temporary lagoons close to the Canabrava River, a tributary of the Santa Teresa River, middle Tocantins River basin, road TO-373, Alvorada do Tocantins municipality, Tocantins State, Brazil, 12°29'46"S, 49°00'51"W, elevation about 290 meters. Holotype: UFRJ 6440. Paratypes: CICCAA, UFRJ. •Valid as Spectrolebias gracilis Costa & Amorim 2018. Current status: Valid as Spectrolebias gracilis Costa & Amorim 2018. Rivulidae: Cynolebiinae. Distribution: Middle Tocantins River basin, Tocantins State, central Brazil. Habitat: freshwater.

gransabanae, Rivulus Lasso [C. A.], Taphorn [D. C.] & Thomerson [J. E.] 1992:298, Figs. 2-3 [Ichthyological Exploration of Freshwaters v. 2 (no. 4); ref. 14222] Quebrada Pacheco, a small creek between Tuperere River II and San Ignacio Yuruaní, Gran Sabana, Estado Bolivar, Venezuela. Holotype: MHNLS 3883. Paratypes: CVULA 5614 (2); FMNH 101112 (10); MBUCV-V-13768 (4 not 1), V-17444 (15); MCNG 16293 (14), 18990 (24), 18993 (30), 19007 (29), 19008 (44), 21349 (12), 21351 (9), 21353 (21); MHNLS 4594 (1), 5182 (1), 5184 (4), 5812 (3). Type catalog: Lasso et al. 1997:48-49 [ref. 23639], Provenzano et al. 1998:16 [ref. 24196]. •Valid as Rivulus gransabanae Lasso, Taphorn & Thomerson 1992 -- (Huber 1992:221 [ref. 20639], Huber 1999:50 [ref. 23834], Verneulen & Isbrücker 2000:189 [ref. 25219] as cf. gransabanae, Lazara 2001:275 [ref. 25711], Costa in Reis et al. 2003:536 [ref. 27061], Radda 2004:21 [ref. 27638], Hrbek et al. 2004:573 [ref. 27910], Suijker & Collier 2006:10 [ref. 28729], Lasso-Alcalá et al. 2006:27 [ref. 28774], Costa 2006:153 [ref. 28875] in subgenus Laimosemion). •Valid as Laimosemion gransabanae (Lasso, Taphorn & Thomerson 1992) -- (Costa 2011:239 [ref. 31655], Vermeulen et al. 2012:187 [ref. 32253]). Current status: Valid as Laimosemion gransabanae (Lasso, Taphorn & Thomerson 1992). Rivulidae: Rivulinae. Distribution: Orinoco River basin, Venezuela. Habitat: freshwater.

griseus, Cynolebias Costa [W. J. E. M.], Lacerda [M. T. C.] & Brasil [G. C.] 1990:11, Figs. 9-10 [Revue française d'Aquariologie Herpétologie v. 17 (no. 1); ref. 16652] Temporary lagoon, Goiás, Munic. de Nova Roma, Brazil, 14°03'S, 44°57"W. Holotype: MZUSP 40119. Paratypes: MZUSP 40120 (3). •Valid as Cynolebias griseus Costa, Lacerda & Brasil 1990 -- (Costa 1995:79 [ref. 22097], Costa 1998:238 [ref. 23578], Costa 1998:76 [ref. 23792], Lazara 2001:77 [ref. 25711], Costa 2001:351 [ref. 25719], Costa 2002:917 [ref. 26505], Costa in Reis et al. 2003:529 [ref. 27061], Costa 2009:146 [ref. 30511], Costa 2014:79 [ref. 33910]). Current status: Valid as Cynolebias griseus Costa, Lacerda & Brasil 1990. Rivulidae: Cynolebiinae. Distribution: Upper Tocantins River basin, Brazil. Habitat: freshwater.

guajira, Austrofundulus Hrbek [T.], Taphorn [D. C.] & Thomerson [J. E.] 2005:28, Figs. 14-15 [Zootaxa No. 825; ref. 28063] Temporary pond 34 kilometers west of Maicao, on road to Río Hacha, Colombia. Holotype: FMNH 108223 [ex FMNH 85252]. Paratypes: FMNH 85251 (4), 85252 (5), 97709 (3); MCNG 17177 (53), 17180 (79); UMMZ 141917 (2). •Valid as Austrofundulus guajira Hrbek, Taphorn & Thomerson 2005 -- (DoNascimiento et al. 2017:101 [ref. 35633]). Current status: Valid as Austrofundulus guajira Hrbek, Taphorn & Thomerson 2005. Rivulidae: Rivulinae. Distribution: Northwestern Venezuela and northeastern Colombia. Habitat: freshwater.

guanabarensis, Atlantirivulus Costa [W. J. E. M.] 2014:13, Figs. 3-5 [Vertebrate Zoology v. 64 (no. 1); ref. 33307] Estado do Rio de Janeiro: Município de Magé: stream within dense forest, Roncador river basin, Citrolândia, Reserva Particular do Patrimônio Natural Campo Escoteiro Geraldo Hugo Nunes, 22° 35′ 31″S, 43°01′ 28″ W, Brazil. Holotype: UFRJ 9825. Paratypes: many at UFRJ. Plus non-type material. •Valid as Atlantirivulus guanabarensis Costa 2014. Current status: Valid as Atlantirivulus guanabarensis Costa 2014. Rivulidae: Rivulinae. Distribution: Rio de Janeira, Brazil. Habitat: freshwater.

guanambi, Hypsolebias Costa [W. J. E. M.] & Amorim [P. F.] 2011:101, Figs. 2-3 [Vertebrate Zoology v. 61 (no. 1); ref. 31380] Seasonal pool close to road BR-030, 14 km west of the city of Guanambi, upper Camaíba de Dentro River drainage, São Francisco River basin, 14°13'42"S, 42°55'12"W, Município de Guanambi, Estado da Bahia, Brazil. Holotype: UFRJ 6861. Paratypes: UFRJ 6072 (2), 6783 (2), 6862 (4, c&s), 6782 (8). In this paper, the author treated Hypsolebias as a species-complex, presumably in Simpsonichthys, but treated Hypsolebias as a valid genus. •Valid as Hypsolebias guanambi Costa & Amorim 2011 -- (Costa et al. 2012:72, 81 [ref. 31845], Costa et al. 2013:1 [ref. 32952], Britzke et al. 2016:134 [ref. 34461], Silva et al. 2020:14 [ref. 37809]). Current status: Valid as Hypsolebias guanambi Costa & Amorim 2011. Rivulidae: Cynolebiinae. Distribution: South America: São Francisco River basin (Bahia State, Brazil). Habitat: freshwater.

guaporensis, Neofundulus Costa [W. J. E. M.] 1988:110, Fig. 6 [Revista Brasileira de Biologia v. 48 (no. 2); ref. 14292] Forte Príncipe da Beira, Rondônia, Brazil. Holotype (unique): MZUSP 36621. •Valid as Neofundulus guaporensis Costa 1988 -- (Costa 1993:618 [ref. 21314], Costa 1998:78 [ref. 23792], Lazara 2001:215 [ref. 25711], Costa in Reis et al. 2003:532 [ref. 27061], Calviño 2005:15 [ref. 28325], Nielsen & Brousseau 2013:114 [ref. 32795], Sarmiento et al. 2014:187 [ref. 35004]). Current status: Valid as Neofundulus guaporensis Costa 1988. Rivulidae: Rivulinae. Distribution: Guaporé River basin, Brazil and Bolivia. Habitat: freshwater.

guarani, Argolebias Alonso [F.], Calviño [P.], Terán [G. E.], Serra [W. S.], Montes [M. M.], García [I. D.], Barneche [J. A.], Almirón [A.], Ciotek [L.], Giorgis [P.] & Casciotta [J.] in Alonso, Terán, Alanís, Calviño, Montes, García, et al. 2023:14, Figs. 4-11 [Zoological Journal of the Linnean Society v. 199 (no. 1); ref. 40292] Seasonal pond on the side of an internal road at Reserva Natural de la Defensa Puerto Península, middle Paraná River basin, Misiones Province, north-east Argentina, −25.677114, −54.578445, elevation 179 meters. Holotype: IBIGEO I473. Paratypes: CI-FML, IBIGEO, MACN. •Valid as Austrolebias guarani (Alonso, Calviño, Terán, Serra, Montes, García, Barneche, Almirón, Ciotek, Giorgis & Casciotta 2023). •Valid as Argolebias guarani Alonso, Calviño, Terán, Serra, Montes, García, Barneche, Almirón, Ciotek, Giorgis & Casciotta 2023 -- (Koerber et al. 2023:4 [ref. 40368], Alonso et al. 2024:304 [ref. 40863]). Current status: Valid as Argolebias guarani Alonso, Calviño, Terán, Serra, Montes, García, Barneche, Almirón et al. 2023. Rivulidae: Cynolebiinae. Distribution: South America: seasonal pond at Reserva Natural de la Defensa Puerto Península, middle Paraná River basin (Misiones, Argentina). Habitat: freshwater.

gymnoventris, Cynolebias Amato [L. H.] 1986:2, Pl. 1 (figs. 1-2) [Comunicaciones Zoologicas del Museo de Historia Natural de Montevideo v. 11 (no. 162); ref. 9170] Floodlands of India Muerta Creek, 150 meters from the bridge on route 13, near Velázquez, Rocha, Uruguay. Holotype: MHNM 2460. Paratypes: MHNM 2444 (7), 2461-63 (1, 7, 14), 2472 (2), 2475 (2); MZUSP 36450-51 (1, 1). Type catalog: Loureiro et al. 2016:412 [ref. 35150]. •Valid as Cynolebias gymnoventris Amato 1986 -- (Malabarba 1989:158 [ref. 14217], Costa 1995:68 [ref. 22097], Costa 1999:301 [ref. 24229], Costa 1999:93 [ref. 24131]). •Valid as Austrolebias gymnoventris (Amato 1986) -- (Costa 1998:75 [ref. 23792], Lazara 2001:61 [ref. 25711], Costa & Cheffe 2001:180 [ref. 25851], Costa & Cheffe 2002:86 [ref. 26518], Costa 2002:917 [ref. 26505], Costa in Reis et al. 2003:527 [ref. 27061], Costa 2006:21 [ref. 28708], Costa 2009:188 [ref. 30417], Costa 2011:100 [ref. 31504], Loureiro et al. 2011:341 [ref. 31392], Litz & Koerber 2014:30 [ref. 33622], Bertaco et al. 2016:424 [ref. 34561], Nión et al. 2016:42 [ref. 35565], Loureiro et al. 2018:11 [ref. 36240], Loureiro et al. 2023:169 [ref. 40506]). •Valid as Gymnolebias gymnoventris (Amato 1986) -- (Alonso et al. 2023:10 [ref. 40292], Koerber et al. 2023:10 [ref. 40355]). Current status: Valid as Gymnolebias gymnoventris (Amato 1986). Rivulidae: Cynolebiinae. Distribution: South America: Laguna dos Patos basin (Uruguay). Habitat: freshwater.

habluetzeli, Papiliolebias Valdesalici [S.], Nielsen [D. T. B.], Brousseau [R.] & Phunkner [J.] 2016:156, Figs. 1-5 [aqua, International Journal of Ichthyology v. 22 (no. 4); ref. 34860] Seasonal pool, about 30 km north of Trinidad, Rio Mamoré basin, Departamento Beni, northern Bolivia, 14°33'16'S, 64°52'04'W. Holotype: CIRA 3271. Paratypes: MSNG, ZSM, ZUEC. •Valid as Papiliolebias habluetzeli Valdesalici, Nielsen, Brousseau & Phunkner 2016 -- (Drawert 2023:28 [ref. 40730]). Current status: Valid as Papiliolebias habluetzeli Valdesalici, Nielsen, Brousseau & Phunkner 2016. Rivulidae: Rivulinae. Distribution: South America: Rio Mamoré basin (Beni, Bolivia). Habitat: freshwater.

haerteli, Cynolebias Schreitmüller [W.] 1937:13 [Das Aquarium: eine Zeitschrift mit Bildern für Liebhaber, Schulen und Naturfreunde, Berlin v. 11 (no. 1); ref. 36064] No types known. Provisional name, not published. •Nomen nudum (Lazara 2001:204 [ref. 25711]). •In the synonymy of Austrolebias wolterstorffi (Ahl 1924) -- (Litz & Koerber 2014:31 [ref. 33622]). •In the synonymy of Megalebias wolterstorffi (Ahl 1924) -- (Lazara 2001:204 [ref. 25711]). Nomen Nudum. Current status: Synonym of Megalebias wolterstorffi (Ahl 1924). Rivulidae: Cynolebiinae.

hamadryades, Hypsolebias Costa [W. J. E. M.], Amorim [P. F.] & Mattos [J. L. O.] 2018:149, Figs. 4, 5C [ZooKeys No. 777; ref. 36034] Temporary pool near road MG-401 at the town of Janaúba, floodplains of Gorutuba River, Verde Grande River drainage, São Francisco River basin, Janaúba municipality, Minas Gerais State, Brazil, 15°48'06"S, 43°19'19"W, elevation about 530 meters. Holotype: UFRJ 6893. Paratypes: UFRJ. •Valid as Hypsolebias hamadryades Costa, Amorim & Mattos 2018. Current status: Valid as Hypsolebias hamadryades Costa, Amorim & Mattos 2018. Rivulidae: Cynolebiinae. Distribution: Middle São Francisco River basin, Brazil. Habitat: freshwater.

haraldsiolii, Rivulus Berkenkamp [H. O.] 1984:430, Figs. 1-3 [Amazoniana v. 8 (no. 4); ref. 8249] Lower rio Itapocú, Estado de Santa Catarina, southeastern Brazil, 27°16'30"S, 48°43'00"W. Holotype: ZMH 6530. Paratypes: ZMH 6531 (3). Type catalog: Huber 1992 [ref. 20639], Wilkens & Dohse 1993:416 [ref. 21161]. •Status uncertain -- (Huber 1992:224 [ref. 20639]). •Valid as Rivulus haraldsiolii Berkenkamp 1984 -- (Costa 1991:582 [ref. 20033], Lazara 2001:275 [ref. 25711], Costa in Reis et al. 2003:536 [ref. 27061], Costa 2004:105 [ref. 27824], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys, Costa 2007:178 [ref. 29203], Costa 2008:47 [ref. 29622] in subgenus Atlantirivulus, Costa 2008:135 [ref. 29871], Costa 2008:199 [ref. 29962], Costa & Lanés 2009:94 [ref. 30256]). •Valid as Atlantirivulus haraldsiolii (Berkenkamp 1984) -- (Costa 2011:244 [ref. 31655], Costa 2014:19 [ref. 33307], Volcan et al. 2024:98 [ref. 41345] as haraldisiolii). Current status: Valid as Atlantirivulus haraldsiolii (Berkenkamp 1984). Rivulidae: Rivulinae. Distribution: South America: Atlantic coastal plain rivers, southeastern Brazil. Habitat: freshwater.

harmonicus, Simpsonichthys Costa [W. J. E. M.] 2010:74, Figs. 1-2 [Ichthyological Exploration of Freshwaters v. 21 (no. 1); ref. 30777] Seasonal pool close to road BR-349, ca. 12 kilometers of the left bank of São Francisco River, 13°15'42"S, 43°31'28"W, Município de Bom Jesus da Lapa, Estado de Bahia, Brazil. Holotype: UFRJ 6696. Paratypes: UFRJ 6697 (14), 6698 (4, c&s). •Valid as Simpsonichthys harmonicus Costa 2010. •Valid as Hypsolebias harmonicus (Costa 2010) -- (Costa 2011:221 [ref. 31654], Costa et al. 2012:73 [ref. 31845], Nielsen et al. 2014:28 [ref. 33143], Nielsen et al. 2014:132 [ref. 33451], Costa et al. 2018:155 [ref. 36034], Silva et al. 2020:14 [ref. 37809]). Current status: Valid as Hypsolebias harmonicus (Costa 2010). Rivulidae: Cynolebiinae. Distribution: South America: floodplains of São Francisco River (Bahia State, Brazil). Habitat: freshwater.

hartii, Haplochilus Boulenger [G. A.] 1890:170 [Annals and Magazine of Natural History (Series 6) v. 6 (no. 32) (art. 19); ref. 17026] Trinidad Island, West Indies. Lectotype: BMNH 1890.4.28.11. Paralectotypes: BMNH 1890.4.28.12-16 (5), 1890.6.12.11-18 (8); ?CAS (2, lost in 1906); MNHN 1890-0305 and 0306 (2); CAS-SU 1128 (1). Type catalog: Bertin & Estève 1950:19 [ref. 19576], Böhlke 1953:53 [ref. 12291], Huber 1992 [ref. 20639]. Lectotype selected by Huber 1992:227 [ref. 20639]. •Valid as Rivulus hartii/R. homiae complex -- (Ghedotti & Wiley 2003:1146 [ref. 27019]). •Valid as Rivulus hartii (Boulenger 1890) -- (Huber 1992:227 [ref. 20639], Huber 1999:49 [ref. 23834], Fuller et al. 1999:293 [ref. 25838], Lazara 2001:276 [ref. 25711], Radda 2004:21 [ref. 27638], Nelson et al. 2004:101 [ref. 27807], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys, Minckley & Marsh 2009:228 [ref. 31114] as harti, Costa & De Luca 2011:356 [ref. 31193], Page et al. 2013:103 [ref. 32708], Vermeulen 2020:45 [ref. 37941]). •Valid as Anablepsoides hartii (Boulenger 1890) -- (Costa 2011:243 [ref. 31655], Phillip et al. 2013:20 [ref. 32896], Valdesalici 2015:241 [ref. 34049], Page et al. 2023:140 [ref. 40505]). Current status: Valid as Anablepsoides hartii (Boulenger 1890). Rivulidae: Rivulinae. Distribution: Caribbean coastal river drainages: Netherland Antilles, Trinidad and Tobago, and Venezuela. Introduced in Mexico. Habitat: freshwater, brackish.

hatinne, Papiliolebias Azpelicueta [M. de las M.], Butí [C.] & García [G.] 2009:314, Figs, 1, 3, 5 [Revue Suisse de Zoologie v. 116 (no. 3-4); ref. 30672] Río Bermejo basin, temporary pond at side of Ruta Nacional 34, 5 killometers north of Embarcación, close to 23°15'S, 64°07'W, Salta Province, Agentina. Holotype: FML 4000. Paratypes: FML 2786 (4). 2963 (11), 4501(10), 4502 (3 c&s); MHNG 2704.014 (6). •Valid as Papiliolebias hatinne Azpelicueta, Butí & García 2009 -- (Koerber 2011:7 [ref. 31122], Nielsen & Brousseau 2014:58 [ref. 33146], Valdesalici & Brousseau 2014:118 [ref. 33449], Koerber 2014:12 [ref. 33621], Sarmiento et al. 2014:187 [ref. 35004], Mirande & Koerber 2015:52 [ref. 35117], Valdesalici et al. 2016:162 [ref. 34860]). •Synonym of Papiliolebias bitteri (Costa 1989) -- (Koerber et al. 2017:8 [ref. 35632]). Current status: Valid as Papiliolebias hatinne Azpelicueta, Butí & García 2009. Rivulidae: Rivulinae. Distribution: Río Bermejo basin, Argentina and Bolivia. Habitat: freshwater.

hellneri, Cynolebias Berkenkamp [H. O.] 1993:8, Figs. [Das Aquarium v. 27 (no. 290); ref. 21369] Pond by the road Manga to Itacarambi, about 10.5 kilometers before Itacarambi, Municipio (Bezirk) Manga, Minas Gerais State, Brazil. Holotype: MZUSP. Paratypes: MZUSP (1); SMF 18445-46 (11, 9). •Valid as Cynolebias hellneri Berkenkamp 1993 -- (Costa 1995:125 [ref. 22097]). •Valid as Simpsonichthys hellneri (Berkenkamp 1993) -- (Costa 1996:130 [ref. 25271], Costa 1998:75 [ref. 23792], Lazara 2001:297 [ref. 25711], Costa in Reis et al. 2003:541 [ref. 27061], Costa & Nielsen 2004:130 [ref. 27825], Costa 2006:17 [ref. 28620], Costa 2007:81 [ref. 29445]). •Valid as Hypsolebias hellneri (Berkenkamp 1993) -- (based on generic placement in Costa 2011 [ref. 31654], Costa et al. 2012:73 [ref. 31845], Nielsen et al. 2014:28 [ref. 33143], Loureiro et al. 2018:11 [ref. 36240], Costa et al. 2018:499 [ref. 36319]). Current status: Valid as Hypsolebias hellneri (Berkenkamp 1993). Rivulidae: Cynolebiinae. Distribution: Middle São Francisco River basin, Minas Gerais State, Brazil. Habitat: freshwater.

hellneri, Moema Costa [W. J. E. M.] 2003:3, Figs. 2-3A [Boletim do Museu Nacional do Rio de Janeiro, Zoologia, Nova Série No. 513; ref. 27634] Río Napo drainage, Amazonian basin, about 1°30'S, 75°30'W, Bellavista, Depto. Loreto, Peru. Holotype: MUSM 20158. Paratypes: UFRJ 4594 (2, 1 c&s), 5444 (4). •Valid as Moema hellneri Costa 2003 -- (Valdesalici et al. 2015:129 [ref. 33902], Valdesalici 2016:66 [ref. 34174], Meza-Vargas et al. 2021:27 [ref. 39298]). Current status: Valid as Moema hellneri Costa 2003. Rivulidae: Rivulinae. Distribution: South America: Amazon basin (Peru). Habitat: freshwater.

heloplites, Cynolebias Huber [J. H.] 1981:1, Fig. [Killi Revue v. 8 (no. 5) (Suppl.); ref. 8591] Lagoa at kilometer 76 from route Fortalaza-Russas, Ceará, Brazil. Holotype: MNHN 1981-1211. Paratypes: MNHN 1981-1212 (6). •Synonym of Cynolebias antenori Tulipano 1973 -- (Costa 1995:57 [ref. 22097], Costa 1996:130 [ref. 25271]). •Synonym of Simpsonichthys antenori (Tulipano 1973) -- (Lazara 2001:295 [ref. 25711], Costa 2003:38 [ref. 26768], Costa in Reis et al. 2003:540 [ref. 27061], Costa 2007:96 [ref. 29445]). •Synonym of Hypsolebias antenori (Tulipano 1973) -- (based on generic placement in Costa 2011 [ref. 31654]). Current status: Synonym of Hypsolebias antenori (Tulipano 1973). Rivulidae: Cynolebiinae. Habitat: freshwater.

hendrichsi, Rivulus Álvarez [J.] & Carranza [J.] 1952:281, Figs. 1-2 [Ciencia (Mexico City) v. 11 (nos 10-12) 1951; ref. 12633] Salto de Agua, Chiapas, southeastern Mexico. Holotype: IBUNAM (number unknown). Paratypes: (22) UMMZ 163237 (2), CAS-SU 17487 (2). Type catalog: Böhlke 1953:54 [ref. 12291], Huber 1992 [ref. 20639]. •Synonym of Rivulus tenuis (Meek 1904) -- (Huber 1992:233 [ref. 20639], Lazara 2001:285 [ref. 25711], Costa in Reis et al. 2003:539 [ref. 27061], Miller 2006:208 [ref. 28615]). •Valid as Cynodonichthys hendrichsi (Álvarez & Carranza 1952) -- (Costa 2011:242 [ref. 31655]). •Synonym of Cynodonichthys tenuis Meek 1904. Current status: Synonym of Cynodonichthys tenuis Meek 1904. Rivulidae: Rivulinae. Habitat: freshwater.

henschelae, Anablepsoides Costa [W. J. E. M.], Bragança [P. H. N.] & Amorim [P. F.] 2013:287, Figs. 3, 4a [Vertebrate Zoology v. 63 (no. 3); ref. 33108] Estado de Roraima: Município de Rorainópolis: stream about 35 km W of Jundiá, road BR-431, Jauaperi river drainage, itself a part of the lower section of the Negro river drainage, Amazonas river basin, 0°13’45"S 60°59’30"W, Brazil. Holotype: UFRJ 9608. Paratypes: UFRJ 9609 (4), 9610 (3 c&s). •Valid as Anablepsoides henschelae Costa, Bragança & Amorim 2013 -- (Nielsen & Veiga 2021:10 [ref. 38269]). Current status: Valid as Anablepsoides henschelae Costa, Bragança & Amorim 2013. Rivulidae: Rivulinae. Distribution: South America: Jauaperi River drainage, Negro River basin, Brazil. Habitat: freshwater.

hermaphroditus, Kryptolebias Costa [W. J. E. M.] 2011:187, Fig. 1 [Ichthyological Exploration of Freshwaters v. 22 (no. 2); ref. 31358] Canal near EMBRAPA, Piracão River basin, a tributary of Sepetiba Bay, Guaratiba, 23°00'18"S, 43°33'35"W, Município do Rio de Janeiro, Estado de Rio de Janeiro, Brazil. Holotype: UFRJ 6863. Paratypes: many at MNRJ and UFRJ. Plus non-type specimens. •Valid as Kryptolebias hermaphroditus Costa 2011 -- (Berbel-Filho et al. 2016:[1] [ref. 34830] on a male, Costa 2016:186 [ref. 34932], Costa et al. 2017:45 [ref. 35684], Silva et al. 2020:14 [ref. 37809], Carvalho-Filho 2023:94 [ref. 40480]). •Synonym of Kryptolebias ocellatus (Hensel 1868) -- (Huber 2017:11 [ref. 35719]). Current status: Synonym of Kryptolebias ocellatus (Hensel 1868). Rivulidae: Kryptolebiatinae. Habitat: freshwater, brackish.

heterostigma, Moema Costa [W. J. E. M.] 2003:291, Figs. 1-2 [Ichthyological Exploration of Freshwaters v. 14 (no. 4); ref. 27396] Seasonal swamp in Rio Cuiabá floodplains, Rio Paraguay basin, 16°30'44.5S, 56°22'40.5"W, Reserva Particular do Patrimônio Natural SESC-PantanalPorto Cercado, Mato Grosso, Brazil. Holotype: MCP 30564. Paratypes: MCP 30565 (1); UFRJ 4900 (1), 5517 (2), 5518 (3, 2 c&s), 5519 (1). •Valid as Moema heterostigma Costa 2003 -- (Valdesalici et al. 2015:129 [ref. 33902], Valdesalici 2016:66 [ref. 34174], Valdesalici 2019:109 [ref. 36959]). Current status: Valid as Moema heterostigma Costa 2003. Rivulidae: Rivulinae. Distribution: Cuiabá River floodplains, Paraguay River basin, Mato Grosso, Brazil. Habitat: freshwater.

heyei, Rivulus Nichols [J. T.] 1914:143 [Bulletin of the American Museum of Natural History v. 33 (art. 10); ref. 14159] Saona Island, Dominican Republic, West Indies. Holotype (unique): AMNH 5069. •Valid as Rivulus heyei Nichols 1914 -- (Lee et al. 1983:59 [ref. 22527]). •Synonym of Rivulus ocellatus Hensel 1868 -- (Huber 1992:236 [ref. 20639]). •Synonym of Rivulus marmoratus Poey 1880 -- (Lazara 2001:280 [ref. 25711], Costa in Reis et al. 2003:538 [ref. 27061]). •Possibly valid, in Cryptolebias -- (Costa 2004:115 [ref. 27763]). •Possilby valid in Kryptolebias -- (Costa 2004:107 [ref. 28584]). •Synonym of Kryptolebias marmoratus (Poey 1880) -- (Costa 2016:189 [ref. 34932], Faloh-Gandarilla et al. 2016:7 [ref. 35177]). Current status: Synonym of Kryptolebias marmoratus (Poey 1880). Rivulidae: Kryptolebiatinae. Habitat: freshwater, brackish.

hildebrandi, Rivulus Myers [G. S.] 1927:123 [Annals and Magazine of Natural History (Series 9) v. 19 (no. 109); ref. 3098] Boquete, Río Chiriquí basin, Panama, elevation 3800 feet. Holotype: UMMZ 56876. Paratypes: UMMZ 56877 (22), USNM 92958 (1). Type catalog: Huber 1992 [ref. 20639]. •Valid as Rivulus hildebrandi Myers 1927 -- (Bussing 1980:330 [ref. 8732], Bussing 1987:122 [ref. 22927], Huber 1992:239 [ref. 20639], Etzel & Berkenkamp 1992:30 [ref. 32437]. Bussing 1998:175 [ref. 24179], Lazara 2001:276 [ref. 25711], Costa in Reis et al. 2003:536 [ref. 27061], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys). •Valid as Cynodonichthys hildebrandi (Myers 1927) -- (Costa 2011:242 [ref. 31655], Angulo et al. 2013:995 [ref. 33194], Angulo et al. 2020:6 [ref. 37425]). Current status: Valid as Cynodonichthys hildebrandi (Myers 1927). Rivulidae: Rivulinae. Distribution: Central America: Pacific slope of Costa Rica and Panama. Habitat: freshwater.

hoetmeri, Anablepsoides Nielsen [D. T. B.], Baptista [A. C., Jr.] & van den Berg [L.] 2016:71, Figs. 1-2 [aqua, International Journal of Ichthyology v. 22 (no. 2); ref. 34406] Estado do Acre, Porto Acre, rio Acre, tributary of the rio Purus, Amazon drainage, Brazil, 9°36'58'S, 67°32'43"W. Holotype: ZUEC 12540. Paratypes: ZUEC. Third author incorrectly written on the article. •Valid as Anablepsoides hoetmeri Nielsen, Baptista & van den Berg 2016 -- (Nielsen 2016:166 [ref. 34861], Valdesalici & Gil 2019:152 [ref. 37074], Nielsen et al. 2022:36 [ref. 39105]). Current status: Valid as Anablepsoides hoetmeri Nielsen, Baptista & van den Berg 2016. Rivulidae: Rivulinae. Distribution: Rio Purus drainage, Amazon basin, Brazil. Habitat: freshwater.

hoignei, Pterolebias Thomerson [J. E.] 1974:31, Figs. 1-2 [Copeia 1974 (no. 1); ref. 7544] Temporary pond, about 1 kilometer north of Caño Benito, Estado Cojedes, Venezuela, 9°16'N, 68°09'W. Holotype: USNM 207402. Paratypes: CAS 27555 (4); FMNH 71665-66 (7, 2); ICNMNH 701 (4), MBUCV-V-7000 (6); SIUE (65, 12 c&s, retained for future distribution); UMMZ 193374 (4); USNM 207403 (9). Type catalog: Ibarra & Stewart 1987:71 [ref. 12367], Provenzano et al. 1998:15 [ref. 24196], Mojica & Agudelo-Zamora 2018:50 [ref. 36127]. •Valid as Pterolebias hoignei Thomerson 1974 -- (Schindler 2004:71 [ref. 28034]). •Valid as Gnatholebias hoignei (Thomerson 1974) -- (Costa 1998:77 [ref. 23792], Lazara 2001:167 [ref. 25711], Costa in Reis et al. 2003:530 [ref. 27061]). Current status: Valid as Gnatholebias hoignei (Thomerson 1974). Rivulidae: Rivulinae. Distribution: Orinoco River basin, Venezuela. Habitat: freshwater.

holmbergi, Cynolebias Berg [C.] 1897:296 [Anales del Museo Nacional de Historia Natural de Buenos Aires v. 5; ref. 14623] Buenos Aires Province, Argentina. Lectotype: MACN 5169. Paralectotypes: MACN 5169 (2) Arroyo Vivoratá, 3826 (1) Río de la Plata. Type catalog: Braga & Piacentino 1994:101 [ref. 23697]. Lectotype listed in Costa in Reis et al. 2003:531 [ref. 27061]; earlier selection not researched. Also designated by Costa 2006 [ref. 28708]. •Synonym of Cynolebias elongatus Steindachner 1881 -- (Costa 1995:78 [ref. 22097]). •Synonym of Megalebias elongatus (Steindachner 1881) -- (Lazara 2001:203 [ref. 25711], Costa in Reis et al. 2003:531 [ref. 27061]). •Synonym of Austrolebias elongatus (Steindachner 1881) -- (Costa 2006:57 [ref. 28708], Litz & Koerber 2014:30 [ref. 33622], Mirande & Koerber 2015:51 [ref. 35117]). •Synonym of Titanolebias elongatus (Steindachner 1881). Current status: Synonym of Titanolebias elongatus (Steindachner 1881). Rivulidae: Cynolebiinae. Habitat: freshwater.

holmiae, Rivulus Eigenmann [C. H.] 1909:50 [Annals of the Carnegie Museum v. 6 (no. 1); ref. 1222] Creek near Holmia, Guyana. Holotype: FMNH 53535 [ex CM 1076]. Paratypes: (17, CM and IU) BMNH 1911.10.31.532-533 (2); CAS 44217 [ex IU 12071] (4); FMNH 52711 (4) 7519 (1), 53535 (1); MCZ 29991 (1); NMW 75390 (1); CAS-SU 21777 (1); USNM 66302 (1); ZMB 18059 (1). Type catalog: Böhlke 1953:54 [ref. 12291], Paepke & Seegers 1986:169 [ref. 19981], Ibarra & Stewart 1987:76 [ref. 12367], Huber 1992:243 [ref. 20639]. •Valid as Rivulus hartii/R. homiae complex -- (Ghedotti & Wiley 2003:1146 [ref. 27019]). •Valid as Rivulus holmiae Eigenmann 1909 -- (Huber 1991:68 [ref. 19721], Huber 1992:243 [ref. 20639], Huber 1999:49 [ref. 23834], Lazara 2001:276 [ref. 25711], Costa in Reis et al. 2003:536 [ref. 27061], Keith et al. 2006:137 [ref. 28851], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys). •Valid as Anablepsoides holmiae (Eigenmann 1909) -- (Costa 2011:243 [ref. 31655], Valdesalici 2015:241 [ref. 34049], Taphorn et al. 2022:36 [ref. 41297]). Current status: Valid as Anablepsoides holmiae (Eigenmann 1909). Rivulidae: Rivulinae. Distribution: South America: upper Potaro River drainage (Guyana) endemic. Habitat: freshwater.

hummelincki, Rachovia de Beaufort [L. F.] 1940:110 [4], Pl. 10b [Freshwater fishes from the Leeward Group, Venezuela and eastern Colombia v. 2; ref. 13161] Poza de San Antonio, east of Carirubana, Paraguaná, Venezuela. Lectotype: ZMA 100401. Paralectotypes: AMNH 20835 [ex ZMA 104445] (1), ZMA 104445 (3), USNM 133088 (1). Type catalog: Nijssen et al. 1982:70 [ref. 19236]. On p. 4 of separate. Lectotype selected by Taphorn & Thomerson 1978:399 [ref. 4337]. •Valid as Rachovia hummelincki de beaufort 1940 -- (Taphorn & Thomerson 1978:399 [ref. 4337], Parenti 1981:486 [ref. 7066], Costa 1998:80 [ref. 23792], Lazara 2001:265 [ref. 25711], Schiwok & Bork 2002:32 [ref. 25833], Costa in Reis et al. 2003:533 [ref. 27061], DoNascimiento et al. 2017:101 [ref. 35633], Berkenkamp 2020:13 [ref. 37695]). Current status: Valid as Rachovia hummelincki de Beaufort 1940. Rivulidae: Rivulinae. Distribution: Magdalena River and Lake Maracaibo basins: north-east Colombia and northwest Venezuela. Habitat: freshwater.

ibicuiensis, Cynolebias Costa [W. J. E. M.] 1999:93, Figs. 1-2 [Revue française d'Aquariologie Herpétologie v. 25 (no. 3/4) [for 1998]; ref. 24131] Rio Ibicui-Mirim, rio Ibicui drainage, road BR-287 between São Pedro do Sul and Santa Maria, Rio Grande do Sul, Brazil. Holotype: MCP 10201. Paratypes: MCP 21171 (1). •Valid as Austrolebias ibicuiensis (Costa 1999) -- (Lazara 2001:61 [ref. 25711], Costa 2002:917 [ref. 26505], Costa in Reis et al. 2003:527 [ref. 27061], Costa 2006:64 [ref. 28708], Bertaco et al. 2016:424 [ref. 34561], Volcan et al. 2017:150 [ref. 35644], Loureiro et al. 2018:11 [ref. 36240]). •Valid as Matilebias ibicuiensis (Costa 1999) -- (Alonso et al. 2023:9 [ref. 40292]). Current status: Valid as Matilebias ibicuiensis (Costa 1999). Rivulidae: Cynolebiinae. Distribution: South America: upper Uruguay River basin, southern Brazil. Habitat: freshwater.

ignescens, Melanorivulus Costa [W. J. E. M.] 2017:53, Figs. 1-2 [ZooKeys No. 645; ref. 35046] Stream tributary to Rio Bandeira, Rio das Garças drainage, Rio Araguaia drainage, Guiratinga municipality, Mato Grosso state, Brazil, 16°21'54"S, 53°47'58"W, elevation approximately 520 meters. Holotype: UFRJ 6875. Paratypes: CICCAA, UFRJ. •Valid as Melanorivulus ignescens Costa 2017. Current status: Valid as Melanorivulus ignescens Costa 2017. Rivulidae: Rivulinae. Distribution: Upper Rio Araguaia basin, Mato Grosso, Brazil. Habitat: freshwater.

igneus, Rivulus Huber [J. H.] 1991:68, Figs. 3a, 3c [Revue française d'Aquariologie Herpétologie v. 18 (no. 3); ref. 19721] Montagne des Singes, 5°10'N, 52°70'W. Holotype: MNHN 1989-1643. Paratypes: MNHN 1979-0647 (31), 1981-0241 (1), 1992-0945 [ex MNHN 1989-1643] (42); ZMA 102249 (2), 102251 (11), 102253-55 (16, 2, 1). •Valid as Rivulus igneus Huber 1991 -- (Huber 1992:248 [ref. 20639], Huber 1999:49 [ref. 23834], Keith et al. 2000:42 [ref. 24547], Lazara 2001:277 [ref. 25711], Costa in Reis et al. 2003:536 [ref. 27061], Keith et al. 2006:137 [ref. 28851], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys). •Valid as Anablepsoides igneus (Huber 1991) -- (Costa 2011:243 [ref. 31655], Valdesalici & Schindler 2013:296 [ref. 33109], Valdesalici 2015:241 [ref. 34049]). Current status: Valid as Anablepsoides igneus (Huber 1991). Rivulidae: Rivulinae. Distribution: South America: Oyapock River basin and adjacent coastal basins, Brazil and French Guiana. Habitat: freshwater.

igneus, Simpsonichthys Costa [W. J. E. M.] 2000:10, Figs. 3-4 [Aquarium (Brasil) v. 3 (no. 25); ref. 25933] Temporary pool close to Igarité, 22 kilometers north of Igarité, 11°28'8.4"S, 43°17'13.4'W, São Francisco basin, Bahia, Brazil, elevation 433 meters. Holotype: MZUSP 56254. Paratypes: MCP 23669 (8); MZUSP 56255 (8); UFRJ 4857 (100), 4868-70 (18, 10, 62), 4872 (33), 4877 (14), 5190-93 (15, 6, 10, 10). •Valid as Simpsonichthys igneus Costa 2000 -- (Costa 2003:43 [ref. 26768], Costa in Reis et al. 2003:541 [ref. 27061], Costa 2006:26 [ref. 28771], Costa 2006:17 [ref. 28620], Costa 2007:106 [ref. 29445]). •Valid as Hypsolebias igneus (Costa 2000) -- (Costa 2011:222 [ref. 31654], Costa et al. 2012:73 [ref. 31845], Costa et al. 2013:1 [ref. 32952], Britzke et al. 2016:134 [ref. 34461], Silva et al. 2020:14 [ref. 37809], Abrantes et al. 2023:549 [ref. 40706]). Current status: Valid as Hypsolebias igneus (Costa 2000). Rivulidae: Cynolebiinae. Distribution: South America: floodplains of the São Francisco River basin (Bahia State, Brazil). Habitat: freshwater.

ilheusensis, Simpsonichthys Costa [W. J. E. M.] & Lima [S. M. Q.] 2010:206, Fig. 1 [Ichthyological Exploration of Freshwaters v. 21 (no. 3); ref. 31041] Temporary pools inside forest, near the road BA-001, 14°35'36"S, 39°03'40"W, Município de Ilhéus, Bahia State, Brazil. Holotype: UFRJ 6690. Paratypes: UFBA 5297 (4); UFRJ 6691 (6), 6692 (2, female c&s). •Valid as Ophthalmolebias ilheusensis (Costa & Lima 2010) -- (Costa 2011:301 [ref. 31187], Costa et al. 2012:73 [ref. 31845], Silva et al. 2020:15 [ref. 37809], Vieira-Guimarães et al. 2024:55 [ref. 41258]). Current status: Valid as Ophthalmolebias ilheusensis (Costa & Lima 2010). Rivulidae: Cynolebiinae. Distribution: South America: floodplains of small coastal river about 700 meter from the shore, Município de Ilhéus, Bahia State (Brazil). Habitat: freshwater.

illuminatus, Rivulus Costa [W. J. E. M.] 2007:194, Figs. 1-2 [Ichthyological Exploration of Freshwaters v. 18 (no. 3); ref. 29337] Near road GO-174, 23 kilometers north of Montividiu, 17°13'35.0"S, 51°09'19.9"W, rio dos Bois drainage, swampy floodplains of Córrego da Queixada, Estado de Goiás, Brazil, elevation 805 meters. Holotype: UFRJ 6463. Paratypes: UFRJ 6464 (2), 6465 (5), 6466 (4, c&s), 6472 (2). •Valid as Rivulus illuminatus Costa 2007 -- (Costa 2008:85 [ref. 29717]). •Valid as Melanorivulus illuminatus (Costa 2007) -- (Costa 2011:241 [ref. 31655], Costa 2012:217 [ref. 32292], Nielsen et al. 2016:87 [ref. 34407], Volcan et al. 2017:92 [ref. 35156]). Current status: Valid as Melanorivulus illuminatus (Costa 2007). Rivulidae: Rivulinae. Distribution: Dos Bois River drainage, Paraná River basin, Goiás, Brazil. Habitat: freshwater.

immaculatus, Rivulus Thomerson [J. E.], Nico [L. G.] & Taphorn [D. C.] 1991:323 [Copeia 1991 (no. 2); ref. 19013] La Mejicana, between Ed Dorado and Sta. Elena de Uairen, Bolivar, Venezuela. Holotype: MBUCV-V-19092. Paratypes: CAS 69412 (2); FMNH 99282 (2), 99283 (4, c&s); MBUCV-V-3983 (42, not 33), V-20290 (1); MCNG 18987 (1), 21355 (6); ?MHNLS (10); USNM 308411 (2).Ferraris 2007:163 [ref. 29155] Type catalog: Lasso et al. 1997:48 [ref. 23639], Provenzano et al. 1998:16 [ref. 24196]. •Valid as Rivulus immaculatus Thomerson, Nico & Taphorn 1991 -- (Huber 1992:252 [ref. 20639], Huber 1999:49 [ref. 23834], Verneulen & Isbrücker 2000:189 [ref. 25219], Lazara 2001:277 [ref. 25711], Costa in Reis et al. 2003:537 [ref. 27061], Radda 2004:21 [ref. 27638], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys, Costa & De Luca 2011:356 [ref. 31193]). •Valid as Anablepsoides immaculatus (Thomerson, Nico & Taphorn 1991) -- (Costa 2011:243 [ref. 31655], Valdesalici 2015:247 [ref. 34049], Taphorn et al. 2022:36 [ref. 41297]). Current status: Valid as Anablepsoides immaculatus (Thomerson, Nico & Taphorn 1991). Rivulidae: Rivulinae. Distribution: South America: Amazon River basin (Guyana and Venezuela). Habitat: freshwater.

imperatrizensis, Melanorivulus Nielsen [D. T. B.] & Pinto [C. S.] 2015:137, Figs. 1-2 [aqua, International Journal of Ichthyology v. 21 (no. 3); ref. 33903] Maranhão, Imperatriz, village of Bananal, rio Tocantins basin, Brazil, 5°39’00.2"S, 47°24’08.4"W, altitude 150 meters. Holotype: ZUEC 10506. Paratypes: ZUEC. •Valid as Melanorivulus imperatrizensis Nielsen & Pinto 2015 -- (Nielsen 2017:66 [ref. 35340], Nielsen & Britzke 2019:41 [ref. 36525], Koerber et al. 2022:75 [ref. 39235]). Current status: Valid as Melanorivulus imperatrizensis Nielsen & Pinto 2015. Rivulidae: Rivulinae. Distribution: South America: middle Rio Tocantins basin (northeastern Brazil). Habitat: freshwater.

inaequipinnatus, Simpsonichthys Costa [W. J. E. M.] & Brasil [G. C.] 2008:246, Figs. 1-2 [Ichthyological Exploration of Freshwaters v. 19 (no. 3); ref. 29968] Seasonal pool in the right bank floodplains of the Tocantins River, 5°20'12"S, 47°51'36"W, Município de Cidelândia, Estado do Maranhão, Brazil. Holotype: UFRJ 6617. Paratypes: UFRJ 6618 (7), 6619 (2, c&s). •Valid as Simpsonichthys inaequipinnatus Costa & Brasil 2008. •Valid as Spectrolebias inaequipinnatus (Costa & Brazil 2008) -- (Nielsen 2013:81 [ref. 32696], Nielsen & Brousseau 2013:116 [ref. 32794], Costa & Amorim 2018:365 [ref. 36019], Koerber et al. 2022:76 [ref. 39235]). Current status: Valid as Spectrolebias inaequipinnatus (Costa & Brasil 2008). Rivulidae: Cynolebiinae. Distribution: South America: Tocantins River basin (northeastern Brazil). Habitat: freshwater.

insulaepinorum, Rivulus de la Cruz [J.] & Dubitsky [A. M.] 1976:2 [Poeyana, Series A, Instituto de Biologia No. 155; ref. 7324] 3 kilometers north of Cayo Piedras, La Fe, Isle of Pines, Cuba. Holotype: IZAC uncat. Paratypes: (3) IZAC uncat. (2). Type catalog: Huber 1992 [ref. 20639]. •Status uncertain -- (Huber 1992:255 [ref. 20639]). •Valid as Rivulus insulaepinorum de la Cruz & Dubitsky 1976 -- (Lee et al. 1983:60 [ref. 22527], Lazara 2001:273 [ref. 25711], Costa in Reis et al. 2003:537 [ref. 27061], Costa 2006:139 [ref. 28875], Costa 2011:239 [ref. 31655]). •Synonym of Rivulus cylindraceus Poey 1860 -- (Ponce de León et al. 2014:404 [ref. 33593], Rodriguez-Silva 2015:295 [ref. 33779], Faloh-Gandarilla et al. 2016:7 [ref. 35177]). Current status: Synonym of Rivulus cylindraceus Poey 1860. Rivulidae: Rivulinae. Distribution: Coastal drainages of Isle of Pines, Cuba (if valid). Habitat: freshwater.

intermedius, Campellolebias Costa [W. J. E. M.] & De Luca [A. C.] in Costa 2006:41, Figs. 5-6 [Zootaxa No. 1227; ref. 28724] Temporary pool in road about 6 kilometers west of Jaquiá, rio Juquiá drainage, rio Ribeira de Iguapé basin, about 24°20'S, 47°35'W, Estado de São Paulo, Brazil. Holotype: UFRJ 6312. Paratypes: UFRJ 6313 (1), 6314 (2), 6315 (4). Plus non-type material. Second author is A. C. De Luca. •Valid as Campellolebias intermedius Costa & De Luca 2006 -- (Ferrer et al. 2014:847 [ref. 33589], Costa 2016:129 [ref. 34776]). Current status: Valid as Campellolebias intermedius Costa & De Luca 2006. Rivulidae: Cynolebiinae. Distribution: Juquiá River drainage, Ribeira de Iguapé River basin, Estado de São Paulo, Brazil. Habitat: freshwater.

intermittens, Rivulus Fels [J. F.] & de Rham [P.] 1981:66, Fig. [Revue française d'Aquariologie Herpétologie v. 8 (no. 3); ref. 8607] "Vivero Forestal El Varillal", 4°04'N, 73°27'W, 34 kilometers from Iquitos on Iquitos-Nauta Road, Peru. Holotype: MHNG 2079.33. Paratypes: MHNG 2079.34 to .45 (12), MNHN 1981-1265 to 1266 (1, 3). Type catalog: Weber 1998:11 [ref. 32707]. •Valid as Rivulus intermittens Fels & de Rham 1981 -- (Ortega & Vari 1986:19 [ref. 9708], Huber 1992:258 [ref. 20639], Lazara 2001:277 [ref. 25711], Costa in Reis et al. 2003:537 [ref. 27061], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys, Valdesalici & Schindler 2011:313 [ref. 31673] in subgenus Cynodonichthys). •Valid as Anablepsoides intermittens (Fels & de Rhamn 1981) -- (Costa 2011:243 [ref. 31655], Valdesalici & Gil 2019:152 [ref. 37074], Meza-Vargas et al. 2021:27 [ref. 39298]). Current status: Valid as Anablepsoides intermittens (Fels & de Rham 1981). Rivulidae: Rivulinae. Distribution: South America: upper Amazon basin (Peru). Habitat: freshwater.

interruptus, Melanorivulus Volcan [M. V.], Severo-Neto [F.] & Lanés [L. E. K.] 2018:264, Figs. 1-2 [Zoosystematics and Evolution v. 94 (no. 2); ref. 35895] First order stream, in the headwaters of Rio Pardo, municipality of Campo Grande, Mato Grosso do Sul state, Brazil, 20°28'11"S, 54°29'25"W, elevation 589 meters. Holotype: MCP 53145. Paratypes: MCP, ZUFMS. •Valid as Melanorivulus interruptus Volcan, Severo-Neto & Lanés 2018 -- (Volcan et al. 2024:1499 [ref. 41484]). Current status: Valid as Melanorivulus interruptus Volcan, Severo-Neto & Lanés 2018. Rivulidae: Rivulinae. Distribution: South America: Rio Pardo drainage, Rio Paraná basin, Mato Grosso do Sul state, Brazil. Habitat: freshwater.

intimus, Cynopoecilus Costa [W. J. E. M.] 2002:18, Fig. 4 [Ichthyological Exploration of Freshwaters v. 13 (no. 1); ref. 26061] Temporary swamp close to a stream tributary to rio Vacacaí, rio Jacuí basin, road BR-392, 6 kilometers northwest of Vila Block, about 29°55'S, 53°50'W, Rio Grande do Sul, Brazil. Holotype: MCP 20816. Paratypes: MCP 20817 (8); MZUSP 52911 (8); NRM 42501 (6); UFRJ 4489 (13), 4490 (6, 2 c&s); UMMZ 234239 (10); USNM 349455 (6). •Valid as Cynopoecilus intimus Costa 2002 -- (Costa in Reis et al. 2003:530 [ref. 27061], Ferrer et al. 2014:847 [ref. 33589], Bertaco et al. 2016:424 [ref. 34561], Costa 2016:130 [ref. 34776], Garcez et al. 2020:[3] [ref. 37602]). Current status: Valid as Cynopoecilus intimus Costa 2002. Rivulidae: Cynolebiinae. Distribution: South America: Atlantic coastal plains adjacent to eastern margin of Laguna dos Patos (Brazil). Habitat: freshwater.

iridescens, Rivulus Fels [J. F.] & de Rham [P.] 1981:66, Fig. [Revue française d'Aquariologie Herpétologie v. 8 (no. 3); ref. 8607] "Arboretum", 3 kilometers from Jenaro Herrera, on the way to Colonia Angamos, 4°53'S, 73°47'W, Peru. Holotype: MHNG 2079.57. Paratypes: MHNG 2079.58 to .62 (5), MNHN 1981-1269 (3). Type catalog: Weber 1998:12 [ref. 32707]. •Status uncertain -- (Huber 1992:261 [ref. 20639]). •Valid as Rivulus iridescens Fels & de Rham 1981 -- (Ortega & Vari 1986:19 [ref. 9708], Lazara 2001:277 [ref. 25711], Costa in Reis et al. 2003:537 [ref. 27061], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys, Valdesalici & Schindler 2011:313 [ref. 31673] in subgenus Cynodonichthys). •Valid as Anablepsoides iridescens (Fels & de Rham 1981) -- (Costa 2011:243 [ref. 31655], Costa 2013:346 [ref. 32528], Nielsen 2016:166 [ref. 34861], Valdesalici & Gil 2019:152 [ref. 37074]). Current status: Valid as Anablepsoides iridescens (Fels & de Rham 1981). Rivulidae: Rivulinae. Distribution: Upper Amazon basin, Peru. Habitat: freshwater.

irregularis, Cynolebias Ahl [E.] 1938:57 [Zoologischer Anzeiger v. 124 (no. 3-4); ref. 17128] Probably Argentina. Holotype (unique): ZMB 21145. Type catalog: Paepke & Seegers 1986:156 [ref. 19981]. Types mentioned: Paepke 1995:94 [ref. 21847]. •Synonym of Cynolebias bellottii Steindachner 1881 -- (Costa 1995:71 [ref. 22097]). •Synonym of Austrolebias bellotti (Steindachner 1881) -- (Lazara 2001:60 [ref. 25711], Costa in Reis et al. 2003:527 [ref. 27061]). •Synonym of Austrolebias bellottii (Streindachner 1881) -- (Costa 2006:104 [ref. 28708], Mirande & Koerber 2015:51 [ref. 35117]). Current status: Synonym of Austrolebias bellottii (Steindachner 1881). Rivulidae: Cynolebiinae. Habitat: freshwater.

isthmensis, Rivulus Garman [S.] 1895:140 [Memoirs of the Museum of Comparative Zoology v. 19 (pt 1); ref. 1538] Río San José, Costa Rica. Holotype (unique): MCZ 27475. •Valid as Rivulus isthmensis Garman 1895 -- (Bussing 1980:332 [ref. 8732], Villa 1982:143 [ref. 36708], Bussing 1987:123 [ref. 22927], Huber 1992:265 [ref. 20639], Bussing 1998:176 [ref. 24179]). •Valid as Rivulus isthmensis Garman 1895, subspecies isthmensis Garman 1895 -- (Lazara 2001:277 [ref. 25711], Costa in Reis et al. 2003:537 [ref. 27061], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys). •Valid as Cynodonichthys isthmensis (Garman 1895) -- (Costa 2011:242 [ref. 31655], Angulo et al. 2013:995 [ref. 33194], Angulo et al. 2023:58 [ref. 40676]). Current status: Valid as Cynodonichthys isthmensis (Garman 1895). Rivulidae: Rivulinae. Distribution: Central America: Costa Rica and Nicaragua. Habitat: freshwater.

itanhaensis, Leptolebias Costa [W. J. E. M.] 2008:153, Figs. 8-10 [Zoological Journal of the Linnean Society v. 153 (no. 1); ref. 29596] Temporary channels within forest, 2.8 kilometers from the road BR-101, Itanhaém, 24°13'08.9"S, 46°55'24.7"W, São Paulo State, Brazil, elevation 14 meters. Holotype: UFRJ 6453. Paratypes: UFRJ 5219 (8, c&s), 6323 (4), 6324 (4). •Valid as Leptolebias itanhaensis Costa 2008 -- (Ferrer et al. 2014:847 [ref. 33589]). •Valid as Leptopanchax itanhaensis (Costa 2008) -- (Costa 2016:128 [ref. 34776], Costa 2019:82 [ref. 36869]). Current status: Valid as Leptopanchax itanhaensis (Costa 2008). Rivulidae: Cynolebiinae. Distribution: Itanhaém, Brazil. Habitat: freshwater.

itapicuruensis, Cynolebias Costa [W. J. E. M.] 2001:362, Fig. 20 [Ichthyological Exploration of Freshwaters v. 12 (no. 4); ref. 25719] Temporary pool in Capim Grosso, rio Itapicurú basin, about 11°20'S, 40°00'W, Bahia, Brazil. Holotype: MZUSP 62562. Paratypes: MZUSP 62563 (6); UFRJ 1766-67 (9, 8), 4514 (1, c&s), 5087 (9), 5115 (3, c&s), 5120 (3, c&s). •Valid as Cynolebias itapicuruensis Costa 2001 -- (Costa in Reis et al. 2003:529 [ref. 27061], Costa 2009:146 [ref. 30511], Costa 2014:80 [ref. 33510], Loureiro et al. 2018:11 [ref. 36240], Silva et al. 2020:13 [ref. 37809], Vieira-Guimarães et al. 2024:54 [ref. 41258]). Current status: Valid as Cynolebias itapicuruensis Costa 2001. Rivulidae: Cynolebiinae. Distribution: South America: Itapicurú River basin, Bahia State (Brazil). Habitat: freshwater.

ivinhemensis, Melanorivulus Volcan [M. V.], Severo-Neto [F.] & Lanés [L. E. K.] 2018:268, Figs. 5-6 [Zoosystematics and Evolution v. 94 (no. 2); ref. 35895] First order stream of Rio Ivinhema, municipality of Nova Andradina, Mato Grosso do Sul state, Brazil, 22°11'53"S, 53°20'12"W, elevation 300 meters. Holotype: MCP 53147. Paratypes: MCP, ZUFMS. •Valid as Melanorivulus ivinhemensis Volcan, Severo-Neto & Lanés 2018. Current status: Valid as Melanorivulus ivinhemensis Volcan, Severo-Neto & Lanés 2018. Rivulidae: Rivulinae. Distribution: South America: Rio Ivinhema drainage, Rio Paraná basin, Mato Grosso do Sul state, Brazil. Habitat: freshwater.

izecksohni, Cynolebias Da Cruz [C. A. G.] 1983:74, Figs. 1-3 [Papéis Avulsos de Zoologia, Museu de Zoologia da Universidade de São Paulo v. 35 (no. 6); ref. 8339] Reserva Florestal da Companhia Vale do Rio Doce [= Reserva Natural Vale, Gávea road, Nativo do Canto Grande], Município de Linhares, Espírito Santo State, Brazil, 19°12'54"S, 39°57'57"W. Holotype: MNRJ 10613. Paratypes: MHNM; MNRJ 10614 (1), 10615 (2); MZUSP 14721-22 (2), 14723-24 (2); USNM 221169 (4); author coll. CAGC 108.1/33 (33), 110.1/33 (33). Type catalog: Loureiro et al. 2016:412 [ref. 35150]. •Synonym of Nematolebias myersi (Carvalho 1971) -- (Lazara 2001:213 [ref. 25711]). •Valid as Simpsonichthys izecksohni (Da Cruz 1983) -- (Costa in Reis et al. 2003:541 [ref. 27061], Costa 2006:16 [ref. 28620]). •Synonym of Cynolebias myersi Carvalho 1971 -- (Costa 1995:44 [ref. 22097], Costa 1996:130 [ref. 25271], Costa 2007:7 [ref. 29445] with author as Cruz). •Valid as Xenurolebias izecksohni (Da Cruz 1983) -- (Costa & Amorim 2014:359 [ref. 33343] with author as Cruz, Vieira-Guimarães et al. 2024:55 [ref. 41258]). Current status: Valid as Xenurolebias izecksohni (Da Cruz 1983). Rivulidae: Cynolebiinae. Distribution: South America: Barra Seca River basin, northern Espírito Santo State (Brazil). Habitat: freshwater.

jaegari, Austrolebias Costa [W. J. E. M.] & Cheffe [M. M.] 2002:84, Figs. 1-2 [aqua, Journal of Ichthyology and Aquatic Biology v. 6 (no. 2); ref. 26518] Swamp at Banhado do Timba, Corredor das Tropas, about 31°30'S, 52°20'W, Pelotas, Rio Grande do Sul, Brazil. Holotype: MCP 28574. Paratypes: MCP 28575 (5); MUCP 2518 (5), 2538 (4), 2583 (5); UFRJ 5429 (7), 5430 (6, 3 c&s). •Valid as Austrolebias jaegari Costa & Cheffe 2002 -- (Costa in Reis et al. 2003:527 [ref. 27061], Costa 2006:25 [ref. 28708], Costa 2011:100 [ref. 31504], Bertaco et al. 2016:424 [ref. 34561], Loureiro et al. 2018:11 [ref. 36240]). •Valid as Gymnolebias jaegari (Costa & Cheffe 2002) -- (Alonso et al. 2023:10 [ref. 40292]). Current status: Valid as Gymnolebias jaegari (Costa & Cheffe 2002). Rivulidae: Cynolebiinae. Distribution: South America: Do Timba Swamp, Rio Grande do Sul State, Laguna dos Patos system, Brazil. Habitat: freshwater.

jalapensis, Rivulus Costa [W. J. E. M.] 2010:194, Figs. 1-2 [Ichthyological Exploration of Freshwaters v. 21 (no. 3); ref. 31043] Stream tributary to Novo River, itself a tributary of the Sono River, Tocantins River drainage, Amazon River basin, 10°18'26"S, 46°57'07"W, Parque Estadual do Jalapão, Estado do Tocantins, Brazil, elevation 382 meters. Holotype: UFRJ 6713. Paratypes: UFRJ 6714 (9), 6715 (2 males, 2 females c&s) •Valid as Melanorivulus jalapensis (Costa 2010) -- (Costa 2011:241 [ref. 31655], Costa 2012:58 [ref. 32069], Costa et al. 2015:32 [ref. 33784], Nielsen & Pinto 2015:137 [ref. 33903], Costa et al. 2016:270 [ref. 35405], Costa 2017:64 [ref. 35046]). Current status: Valid as Melanorivulus jalapensis (Costa 2010). Rivulidae: Rivulinae. Distribution: Sono River drainage, Tocantins River basin, central Brazil. Habitat: freshwater.

janaubensis, Simpsonichthys Costa [W. J. E. M.] 2006:27, Figs. 1-2 [Zootaxa No. 1306; ref. 28771] Rio Gorutuba floodplains, rio Verde Grande drainage, middle rio São Francisco basin, Janaúba, 15°48'05.9"S, 43°19'13.5", western Minas Gerais State Brazil, elevation 556 meters. Holotype: UFRJ 5409 (male). Paratypes: MCP 40138 (5); UFRJ 5409 (2 females), 5410 (6, c&s), 5411 (24), 6076 (10). •Valid as Simpsonichthys janaubensis Costa 2006 -- (Costa 2007:113 [ref. 29445]). •Valid as Hypsolebias janaubensis (Costa 2006) -- (Costa & Amorim 2011:99 [ref. 31380], Costa 2011:222 [ref. 31654], Costa et al. 2012:72, 84 [ref. 31845], Costa et al. 2013:1 [ref. 32952], Britzke et al. 2016:134 [ref. 34461], Loureiro et al. 2018:11 [ref. 36240]). Current status: Valid as Hypsolebias janaubensis (Costa 2006). Rivulidae: Cynolebiinae. Distribution: Gorutuba River floodplains, Verde Grande River drainage, São Francisco River basin, Minas Gerais State, Brazil. Habitat: freshwater.

janeiroensis, Rivulus Costa [W. J. E. M.] 1991:583, Fig. 1 [Revue Suisse de Zoologie v. 98 (no. 3); ref. 20033] Forest stream, near Silva Jardim, Rio São Joao basin, Rio de Janeiro state, Brazil. Holotype: MZUSP 41383. Paratypes: MHNG 2512.85 (2); MZUSP 41384 (6); UFRJ 129 (2), 130 (2, 1 c&s). Type catalog: Huber 1992 [ref. 20639]. •Status uncertain -- (Huber 1992:270 [ref. 20639]). •Valid as Rivulus janeiroensis Costa 1991 -- (Lazara 2001:278 [ref. 25711], Costa in Reis et al. 2003:537 [ref. 27061], Costa 2004:105 [ref. 27824], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys, Costa 2008:47 [ref. 29622] in subgenus Atlantirivulus, Costa 2008:135 [ref. 29871], Costa & Lanés 2009:94 [ref. 30256]). •Valid as Atlantirivulus janeiroensis (Costa 1991) -- (Costa 2011:244 [ref. 31655], Costa 2014:19 [ref. 33307]). Current status: Valid as Atlantirivulus janeiroensis (Costa 1991). Rivulidae: Rivulinae. Distribution: Atlantic coastal river basins, Brazil. Habitat: freshwater.

jari, Anablepsoides Costa [W. J. E. M.], Bragança [P. H. N.] & Amorim [P. F.] 2013:284, Fig. 1 [Vertebrate Zoology v. 63 (no. 3); ref. 33108] Estado do Amapá, Município de Laranjal do Jari, stream tributary of Jari river, lower Amazonas river basin, 0°45′55″S, 52°31′17″W, Brazil. Holotype: UFRJ 9569. Paratypes: UFRJ 8839 (1), 9570 (3); INPA 2244 (20). •Valid as Anablepsoides jari Costa, Bragança & Amorim 2013 -- (Nielsen 2016:166 [ref. 34861]). Current status: Valid as Anablepsoides jari Costa, Bragança & Amorim 2013. Rivulidae: Rivulinae. Distribution: Lower Jari River basin, Amapá, Brazil. Habitat: freshwater.

jauaperi, Laimosemion (Owiyeye) Costa [W. J. E. M.] & Bragança [P. H. N.] 2013:94, Figs. 1-2 [Ichthyological Exploration of Freshwaters v. 24 (no. 1); ref. 32797] Pool adjacent to stream about 35 km West of Jundiá, road BR-431, Jauaperi River drainage, Roraima, Brazil, 0°13'45"S, 60°59'30"W, Holotype: UFRJ 9277. Paratype: UFRJ. •Valid as Rivulus jauaperi (Costa & Bragança 2013) -- (Vermeulen 2023:109 [ref. 40177]). •Valid as Laimosemion jauaperi Costa & Bragança 2013 -- (Costa & Lazzarotto 2014:372 [ref. 33247], Valdesalici 2016:279 [ref. 34270], Valdesalici & Nielsen 2017:102 [ref. 35496]). Current status: Valid as Laimosemion jauaperi Costa & Bragança 2013. Rivulidae: Rivulinae. Distribution: Jauaperi River drainage, Roraima, Brazil. Habitat: freshwater.

javahe, Rivulus Costa [W. J. E. M.] 2007:63, Figs. 8-9 [aqua, International Journal of Ichthyology v. 13 (no. 2); ref. 29394] Stream tributary to Rio Verde, Rio Araguaia Basin, at road GO-16 crossing, ca. 30 kilometers north of São Miguel do Araguaia, Goiás States, Brazil, 13°04'05.3"S, 49°57'20,0"W, altitude 323 meters. Holotype: UFRJ 8386. Paratypes:( 27) UFRJ 1482 (18), 2108 (4), 6387 (3), 6388 (2). Plus non-types. •Valid as Rivulus javahe Costa 2007 -- (Costa 2010:369 [ref. 30690]). •Valid as Melanorivulus javahe (Costa 2007) -- (Costa 2011:241 [ref. 31655], Costa 2016:141 [ref. 34900] as javaeh, Nielsen 2017:66 [ref. 35340], Nielsen & Britzke 2019:42 [ref. 36525]). Current status: Valid as Melanorivulus javahe (Costa 2007). Rivulidae: Rivulinae. Distribution: Middle Araguaia River basin, central Brazil. Habitat: freshwater.

juanderibaensis, Moema Drawert [H. A.] 2022:4, Figs. 1-5 [Neotropical Ichthyology v. 20 (no. 4): e220067; ref. 39805] Temporary pool within forest ca. 5 km southeast of Santa Rosa del Sara, Juan Deriba ranch, municipality of Santa Rosa del Sara, Piraí watershed, upper Madeira drainage, Amazon basin, Santa Cruz, Bolivia, 17°07'17.6"S, 63°33'23.3"W. Holotype: MNKP 16539. Paratypes: MNKP. Plus additional non-type material. •Valid as Moema juanderibaensis Drawert 2022 -- (Drawert 2023:32 [ref. 40730]). Current status: Valid as Moema juanderibaensis Drawert 2022. Rivulidae: Rivulinae. Distribution: South America: Piraí watershed, upper Madeira drainage, Amazon basin, Santa Cruz (Bolivia). Habitat: freshwater.

juanlangi, Austrolebias Costa [W. J. E. M.], Cheffe [M. M.], Salvia [H.] & Litz [T.] in Costa 2006:86, Fig. 34 [Zootaxa No. 1213; ref. 28708] Temporary swamp near banhado do Minuano, road BR-153, Rio Jaguão basin, a tributary of lagoa Mirim, laguna dos Patos System, 31°40'48"S, 54°08'45"W, Jaguarão, Rio Grande do Sul, Brazil. Holotype: UFRJ 6199. Paratypes: Many lots at CIMC, MCP, MUNH [MUNHIN], UFRJ. Plus non-type material. •Valid as Austrolebias juanlangi Costa, Cheffe, Salvia & Litz 2006 -- (Costa 2009:188 [ref. 30417], Litz & Koerber 2014:30 [ref. 33622], Bertaco et al. 2016:424 [ref. 34561], Nión et al. 2016:42 [ref. 35565], Volcan et al. 2017:150 [ref. 35644], Loureiro et al. 2018:11 [ref. 36240], Loureiro et al. 2023:166 [ref. 40506]). •Valid as Matilebias juanlangi (Costa, Cheffe, Salvia & Litz 2006) -- (Alonso et al. 2023:9 [ref. 40292], Koerber et al. 2023:11 [ref. 40355]). Current status: Valid as Matilebias juanlangi (Costa, Cheffe, Salvia & Litz 2006). Rivulidae: Cynolebiinae. Distribution: South America: Lake Mirim basin and upper Negro River basin (Brazil and Uruguay). Habitat: freshwater.

jucundus, Rivulus Huber [J. H.] 1992:273, Pl. 37 (figs. b-c) [Review of Rivulus: Ecobiogeography -- Relationships; ref. 20639] Río Pastaza, near Puyo, Pastaza dept., Ecuador, elevation 900-1000 meters. Holotype: MHNG 2532.90. Paratypes: UMMZ 203874 (3). •Valid as Rivulus jucundus Huber 1992 -- (Lazara 2001:278 [ref. 25711], Costa in Reis et al. 2003:537 [ref. 27061], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys, Barriga Salazar 2014:117 [ref. 35745]). •Valid as Anablepsoides jucundus (Huber 1992) -- (Costa 2011:243 [ref. 31655]). Current status: Valid as Anablepsoides jucundus (Huber 1992). Rivulidae: Rivulinae. Distribution: Amazon River basin, Ecuador. Habitat: freshwater.

jurubatibensis, Rivulus Costa [W. J. E. M.] 2008:136, Figs. 1-2 [Ichthyological Exploration of Freshwaters v. 19 (no. 2); ref. 29871] Município de Quissamã, swamp close to Lagoa do Pires, Parque Nacional de Jurubatiba, 22°10'50"S, 41°23'41"W, Estado do Rio de Janeiro, Brazil. Holotype: UFRJ 6611. Paratypes: UFRJ 6242 (8), 6612 (8), 6613 (4, c&s). •Valid as Rivulus jurubatibensis Costa 2008 -- (Costa & Lanés 2009:94 [ref. 30256]). •Valid as Atlantirivulus jurubatibensis (Costa 2008) -- (Costa 2011:244 [ref. 31655], Di Dario et al. 2013:263 [ref. 37503], Costa 2014:19 [ref. 33307]). Current status: Valid as Atlantirivulus jurubatibensis (Costa 2008). Rivulidae: Rivulinae. Distribution: South America: Lagoa do Pires, southern Brazil. Habitat: freshwater.

karaja, Rivulus Costa [W. J. E. M.] 2007:65, Figs. 10-11 [aqua, International Journal of Ichthyology v. 13 (no. 2); ref. 29394] Strean tributary to Rio Dueré, Rio Formosa drainage, Rio Araguaia Basin, near road BR-153, 10 kilometers south of Rio Dueré Municipality, Tocantins State, Brazil, 11°12'36.9"S, 48°55'52.6"W, elevation 270 meters. Holotype: UFRJ 6485. Paratypes: (2) UFRJ 6486 (1), 6487 (1 c&s). •Valid as Rivulus karaja Costa 2007 -- (Costa 2010:369 [ref. 30690]). •Valid as Melanorivulus karaja (Costa 2007) -- (Costa 2011:241 [ref. 31655], Costa 2016:136 [ref. 34900], Costa et al. 2016:270 [ref. 35405], Nielsen 2017:66 [ref. 35340], Nielsen & Britzke 2019:42 [ref. 36525]). Current status: Valid as Melanorivulus karaja (Costa 2007). Rivulidae: Rivulinae. Distribution: Middle Rio Tocantins drainage, central Brazil. Habitat: freshwater.

katukina, Anablepsoides Nielsen [D. T. B.], Hoetmer [J. W.] & Vandenkerkhove [E.] 2023:298 [Zootaxa 5323 (no. 2); ref. 40342] Stream tributary of Igarapé Canela Fina, Rio Juruá drainage, Amazon basin, Acre State, Brazil, 07°30'51.8"S, 72°42'43.2"W. Holotype: ZUEC 17360. Paratypes: ZUEC 5583 (13), 13043 (11), 13044 (93), 17361 (8). Appeared first in an unavailable publication, ref. 39105, p. 29, Figs. 1-2. •Valid as Anablepsoides katukina Nielsen, Hoetmer & Vandenkerkhove 2023. Current status: Valid as Anablepsoides katukina Nielsen, Hoetmer & Vandenkerkhove 2023. Rivulidae: Rivulinae. Distribution: South America: Rio Juruá drainage, Amazon basin, Brazil. Habitat: freshwater.

kayabi, Rivulus Costa [W. J. E. M.] 2008:346, Figs. 1-2 [Ichthyological Exploration of Freshwaters v. 18 (no. 4) [for 2007]; ref. 29385] Stream crossing road between Alta Floresta and Porto de Areia, 12 kilometers from the later, Teles Pires River drainage, Tapajós River basin, 9°44'09"S, 56°01'24"W, Munic. de Alta Floresta, Est. de Mato Grosso, Brazil, elevation 261m. Holotype: UFRJ 6523. Paratypes: Many lots at UFRJ. Plus non-type specimens. •Valid as Melanorivulus kayabi (Costa 2008) -- (Costa 2016:124 [ref. 34900], Costa et al. 2016:270 [ref. 35405], Nielsen 2017:65 [ref. 35340], Nielsen & Britzke 2019:41 [ref. 36525]). Current status: Valid as Melanorivulus kayabi (Costa 2008). Rivulidae: Rivulinae. Distribution: Tapajós River and Xingu River basins, southern Brazil. Habitat: freshwater.

kayapo, Rivulus Costa [W. J. E. M.] 2006:50, Figs. 1-2 [Zootaxa No. 1368; ref. 28876] Stream near kilometer 52 of road GO-221, Rio Bonito drainage, upper Rio Caiapó basin (itself part of araguaia basin), Estado de Goiás, Brazil, 16°41'52.4"S, 51°25'13.6"W, elevation 685 meters. Holotype: UFRJ 6380. Paratypes: MCP 40140 (3); UFRJ 6381 (12), 6382 (5, c&s). •Valid as Rivulus kayapo Costa 2006 -- (Costa 2008:85 [ref. 29717]). •Valid as Melanorivulus kayapo (Costa 2006) -- (Costa 2011:241 [ref. 31655], Costa 2012:217 [ref. 32292], Nielsen et al. 2016:87 [ref. 34407], Costa et al. 2016:270 [ref. 35405]). Current status: Valid as Melanorivulus kayapo (Costa 2006). Rivulidae: Rivulinae. Distribution: Upper Araguaia River basin, Goiás, Brazil. Habitat: freshwater.

kenwoodi, Moema Valdesalici [S.] 2016:68, Figs. 1-2 [Journal of the American Killifish Association v. 48 (no. 3) (May/June 2015); ref. 34174] Departmento Madre de Dios: Tambopata, temporary pool within forest, Manuripe river system, Madre de Dios river drainage, Amazonian basin, Peru, 12°4'28"S, 69°5'30"W. Holotype: MUSM 47553. Paratypes: MSNG. •Valid as Moema kenwoodi Valdesalici 2016. Current status: Valid as Moema kenwoodi Valdesalici 2016. Rivulidae: Rivulinae. Distribution: Manuripe river system, Peru. Habitat: freshwater.

kirovskyi, Rivulus Costa [W. J. E. M.] 2004:10, Fig. 1 [Neotropical Ichthyology v. 2 (no. 1); ref. 27656] Temporary pools near igarapé Acará, lower rio Negro drainage, rio Amazonas basin, about 3°00'S, 60°30'W, Reserva Ducke, Manaus, Estado do Amazonas, Brazil, elevation 90 meters. Holotype: UFRJ 5935. Paratypes: INPA 1850 (2); UFRJ 5936 (1, c&s), 5937 (1, c&s), 5938-39 (1, 2). •Valid as Rivulus kirovskyi Costa 2004 -- (Costa 2004:2 [ref. 27923], Costa 2006:157 [ref. 28875] in subgenus Owiyeye, Schindler & Valdesalici 2011:109 [ref. 31382], Vermeulen 2023:109 [ref. 40177]). •Valid as Laimosemion kirovskyi (Costa 2004) -- (Costa 2011:239 [ref. 31655], Costa & Bragança 2013:95 [ref. 32797], Costa & Lazzarotto 2014:372 [ref. 33247], Valdesalici 2016:279 [ref. 34270]). Current status: Valid as Laimosemion kirovskyi (Costa 2004). Rivulidae: Rivulinae. Distribution: Floodplains of igarapé Acará, Amazon River basin, northern Brazil. Habitat: freshwater.

kuelpmanni, Rivulus Berkenkamp [H. O.] & Etzel [V.] 1993:17 [Deutsche Killifisch Gemeinschaft Journal v. 25 (no. 2); ref. 20600] Provinz Bocas del Toro, at foot of Cordilera Central, 20 kilometers from Punta Peña, Panama, 8°70'N, 88°15'W, elevation 200 meters. Holotype: SMF 18439. Paratypes: SMF 18440 (8). •Valid as Rivulus kuelpmanni Berkenkamp & Etzel 1993 -- (Berkenkamp & Etzel 1999:64 [ref. 23985], Lazara 2001:278 [ref. 25711], Costa in Reis et al. 2003:537 [ref. 27061], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys). •Valid as Cynodonichthys kuelpmanni (Berkenkamp & Etzel 1993) -- (Costa 2011:242 [ref. 31655]). Current status: Valid as Cynodonichthys kuelpmanni (Berkenkamp & Etzel 1993). Rivulidae: Rivulinae. Distribution: Caribbean river drainages, Panama. Habitat: freshwater.

kunzei, Melanorivulus Costa [W. J. E. M.] 2012:214, Figs. 3-4 [Ichthyological Exploration of Freshwaters v. 23 (no. 3); ref. 32292] Road BR-158, about 64 km north of Jataí town, in a small stream tributary to upper Caiapó River, an upper tributary to Araguaia River, Município de Jataí, Estado de Goiás, Brazil, 17°01'55"S, 51°51'03"W, altitude 729 meters. Holotype: UFRJ 8423. Paratypes: UFRJ 8421 (8), 8422 (11). •Valid as Melanorivulus kunzei Costa 2012. Current status: Valid as Melanorivulus kunzei Costa 2012. Rivulidae: Rivulinae. Distribution: Araguaia river basin, Brazil. Habitat: freshwater.

lacerdai, Plesiolebias Costa [W. J. E. M.] 1989:196, Fig. 2 [Comunicações do Museu de Ciências da PUCRS, Série Zoologia v. 2 (no. 10); ref. 14436] Near Rio das Mortes, close to road to Cocalinhos, Mato Grosso, Brazil. Holotype: MNRJ 11556. Paratypes: MCP 12799 (2), MNRJ 11557 (3). •Valid as Plesiolebias lacerdai Costa 1989 -- (Costa 1991:377 [ref. 13611], Costa 1995:30 [ref. 22097], Costa 1995:73 [ref. 21612], Costa 1998:328 [ref. 23324], Costa 1998:81 [ref. 23792], Costa & Le Bail 1999:1028 [ref. 24187], Lazara 2001:257 [ref. 25711], Costa et al. 2003:144 [ref. 26946], Costa in Reis et al. 2003:533 [ref. 27061]). Current status: Valid as Plesiolebias lacerdai Costa 1989. Rivulidae: Rivulinae. Distribution: Araguaia River basin, Brazil. Habitat: freshwater.

lacortei, Cynolebias Lazara [K. J.] 1991:141, Figs. 2, 5 [Journal of the American Killifish Association v. 23 (no. 5); ref. 20508] Temporary pool, Aruana, Goiás, Estado de Goiás, Brazil, 14°57'00"S, 51°01'23.7"W, elevation 243 meters. Holotype: MZUSP 38805. Paratypes: AMNH 59189 (2, 1 c&s), 59197 (3); MZUSP 38806-07 (2). •Valid as Maratecoara lacortei (Lazara 1991) -- (Costa 1995:22 [ref. 22097], Costa 1995:70 [ref. 21612], Costa 1998:82 [ref. 23792], Lazara 2001:201 [ref. 25711], Costa et al. 2003:144 [ref. 26946], Costa in Reis et al. 2003:531 [ref. 27061], Costa 2007:32 [ref. 28993], Nielsen et al. 2014:90 [ref. 33275]). Current status: Valid as Maratecoara lacortei (Lazara 1991). Rivulidae: Rivulinae. Distribution: Araguaia-das Mortes river basin, Estado do Goiás, Brazil. Habitat: freshwater.

lacustris, Rivulus beniensis Myers [G. S.] 1927:133 [Bulletin of the Museum of Comparative Zoology v. 68 (no. 3); ref. 3096] Lagoons along shores of Lake Rogoagua, Bolivia. Lectotype: UMMZ 66396. Paralectotypes: CAS 76351 (36) [=IU 17258, in part], MCZ 31581 (5), UMMZ 66396b (9), USNM 86812 (5). Type information: Huber 1992 [ref. 20639]. Lectotype selected in Fels & Huber 1985: [ref. 8162]. •Doubtfully valid -- (Huber 1992:277 [ref. 20639]). •Synonym of Rivulus beniensis Myers 1927, but a valid subspecies as described -- (Lazara 2001:270 [ref. 25711]). •Synonym of Rivulus beniensis Myers 1927 -- (Costa in Reis et al. 2003:534 [ref. 27061], Costa 2006:150 [ref. 28875]). •Synonym of Anablepsoides beniensis (Myers 1927). Current status: Synonym of Anablepsoides beniensis (Myers 1927). Rivulidae: Rivulinae. Habitat: freshwater.

ladigesi, Cynolebias Foersch [W.] (ex Myers) 1958:257, Figs. [Die Aquarien- und Terrarienzeitschrift (DATZ) v. 11 (no. 9); ref. 20290] Unknown locality, Brazil. Paratypes: ZSM 15481 (1), 15482-83 (2). Non-types [Myers specimens]: CAS-SU 50192 (1), 50193 (1). Type catalog: Neumann 2011:276 [ref. 31652]. Authors use Foersch instead of Myers •Synonym of Cynolebias minimus Myers 1942 -- (Costa 1988:558 [ref. 14540]). •Synonym of Leptolebias minimus (Myers 1942) -- (Costa 1995:89 [ref. 22097], Lazara 2001:194 [ref. 25711], Costa in Reis et al. 2003:531 [ref. 27061]). •Synonym of Notholebias minimus (Myers 1942) -- (Costa 2008:157 [ref. 29596]). Current status: Synonym of Notholebias minimus (Myers 1942). Rivulidae: Cynolebiinae. Habitat: freshwater.

lanceolatus, Rivulus Eigenmann [C. H.] 1909:51 [Annals of the Carnegie Museum v. 6 (no. 1); ref. 1222] Rockstone, Guyana. Holotype (unique): FMNH 53537 [ex CM 1084]. Type catalog: Henn 1928:86 [ref. 12305], Ibarra & Stewart 1987:76 [ref. 12367]. Name available from features presented in key on p. 49. •Status uncertain -- (Huber 1992:279 [ref. 20639]). •Valid as Rivulus lanceolatus Eigenmann 1909 -- (Lazara 2001:278 [ref. 25711], Costa in Reis et al. 2003:537 [ref. 27061], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys). •Valid as Anablepsoides lanceolatus (Eigenmann 1909) -- (Costa 2011:243 [ref. 31655], Taphorn et al. 2022:36 [ref. 41297]). Current status: Valid as Anablepsoides lanceolatus (Eigenmann 1909). Rivulidae: Rivulinae. Distribution: South America: Atlantic coastal river basins (Guyana) endemic. Habitat: freshwater.

larissae, Melanorivulus Ywamoto [E. V.], Nielsen [D. T. B.] & Oliveira [C.] 2020:126, Figs. 1-2 [Zootaxa 4852 (no. 1); ref. 37763] Ribeirão Santa Rita, tributary of Rio Grande, Rio Paraná basin, Ouroeste, São Paulo state, Brazil, 19°59'56"S, 50°22'55"W, elevation 494 meters. Holotype: ZUEC 17154. Paratypes: LBP 29539 (2), MZUSP 123086 (2), ZUEC 17155 (10). •Valid as Melanorivulus larissae Ywamoto, Nielsen & Oliveira 2020. Current status: Valid as Melanorivulus larissae Ywamoto, Nielsen & Oliveira 2020. Rivulidae: Rivulinae. Distribution: Rio Grande drainage, Rio Paraná basin, northwestern São Paulo state, Brazil. Habitat: freshwater.

lazzarotoi, Rivulus Costa [W. J. E. M.] 2007:124, Figs. 1-2 [aqua, International Journal of Ichthyology v. 12 (no. 3); ref. 29225] Município de Angra dos Reis, stream close to road RJ-155, rio Jurumirim basin, 22°55'24.7"S, 44°18'51.4"W, Estado do Rio de Janeiro, Brazil, elevation 9 meters. Holotype: UFRJ 6435. Paratypes: UFRJ 6436 (6), 7211 (9), 7213 (4, c&s). •Valid as Rivulus lazzarotoi Costa 2007 -- (Costa 2008:47 [ref. 29622] in subgenus Atlantirivulus Costa 2008:135 [ref. 29871]). •Valid as Atlantirivulus lazzarotoi (Costa 2007) -- (Costa 2011:244 [ref. 31655]). Current status: Valid as Atlantirivulus lazzarotoi (Costa 2007). Rivulidae: Rivulinae. Distribution: Jurumirim River basin, Brazil. Habitat: freshwater.

leali, Melanorivulus Costa [W. J. E. M.] 2013:278, Figs. 1-2 [Vertebrate Zoology v. 63 (no. 3); ref. 33107] Estado de São Paulo: Município de Serra Azul: stream tributary of Tamanduazinho river, Pardo river drainage, itself part of Grande river drainage, upper Paraná river basin, 21°20‘00"S, 47°34‘20"E, Brazil, altitude about 700 meters. Holotype: UFRJ 6866. Paratypes: UFRJ 6359 (19), 6540 (4). •Valid as Melanorivulus leali Costa 2013 -- (Nielsen et al. 2016:88 [ref. 34407], Volcan et al. 2017:92 [ref. 35156], Volcan et al. 2018:275 [ref. 35895], Ywamoto et al. 2020:128 [ref. 37763]). Current status: Valid as Melanorivulus leali Costa 2013. Rivulidae: Rivulinae. Distribution: Rio Pardo drainage, Paraná river basin, Mato Grosso do Sul state, Brazil. Habitat: freshwater.

leitaoi, Cynolebias Da Cruz [C. A. G.] & Peixoto [O. L.] 1992:638, Figs. 2-4 [Revista Brasileira de Zoologia v. 7 (no. 4) (for 15 Dec. 1991); ref. 22098] Swamp near Mucuri, southern Bahia State, Brazil. Holotype: MNRJ 11646. Paratypes: CAGC 130.1/20 (20), 131.1/9 (9); MNRJ 11647-48 (2, 5). •Valid as Leptolebias leitaoi (Da Cruz & Peixoto 1992) -- (Costa 1995:92 [ref. 22097], Da Cruz & Peixoto 1992, Costa 1998:73 [ref. 23792], Lazara 2001:193 [ref. 25711], Costa in Reis et al. 2003:530 [ref. 27061], Costa 2008:148 [ref. 29596], Ferrer et al. 2014:847 [ref. 33589]). •Valid as Mucurilebias leitaoi (Da Cruz & Peixoto 1992) -- (Costa 2014:26 [ref. 33309], Costa 2016:127 [ref. 34776], Silva et al. 2020:15 [ref. 37809], Vieira-Guimarães et al. 2024:55 [ref. 41258]). Current status: Valid as Mucurilebias leitaoi (Da Cruz & Peixoto 1992). Rivulidae: Cynolebiinae. Distribution: South America: Mucurí River basin, Bahia State (Brazil). Habitat: freshwater.

leohoignei, Austrofundulus Hrbek [T.], Taphorn [D. C.] & Thomerson [J. E.] 2005:19, Figs. 9-10 [Zootaxa No. 825; ref. 28063] Temporary pond 4 kilometers north of Sanare on road to San Juan de Los Cayos, Río Aroa drainage, Falcón state, Venezuela. Holotype: FMNH 108224 [ex FMNH 85266]. Paratypes: FMNH 85226 (9), 92574 (33); MCNG 32100 (1) •Valid as Austrofundulus leohoignei Hrbek, Taphorn & Thomerson 2005. Current status: Valid as Austrofundulus leohoignei Hrbek, Taphorn & Thomerson 2005. Rivulidae: Rivulinae. Distribution: Aroa River drainage, Venezuela. Habitat: freshwater.

leoni, Austrofundulus Hrbek [T.], Taphorn [D. C.] & Thomerson [J. E.] 2005:25, Figs. 12-13 [Zootaxa No. 825; ref. 28063] Temorary pond about 5 kilometers from the junction of the road to Machiques between Macoa and Río Yasa, Lake Maracaibo basin, Venezuela. Holotype: FMNH 108225 [ex FMNH 85268]. Paratypes: FMNH 85268 (10), 85724 (26); MCNG 33448 (6), 39145-47 (1, 6, 4). •Valid as Austrofundulus leoni Hrbek, Taphorn & Thomerson 2005. Current status: Valid as Austrofundulus leoni Hrbek, Taphorn & Thomerson 2005. Rivulidae: Rivulinae. Distribution: Lowlands of Lake Maracaibo basin, Venezuela. Habitat: freshwater.

leptocephalus, Cynolebias Costa [W. J. E. M.] & Brasil [G. C.] 1993:196, Figs. 4-5 [Ichthyological Exploration of Freshwaters v. 4 (no. 3); ref. 21101] Swamp near Guanambí, 14°20'S, 42°51'W, rio São Francisco basin, Bahia State, Brazil. Holotype: MZUSP 43676. Paratypes: MZUSP 43677 (1); UFRJ 687 (2), 688 (1). •Valid as Cynolebias leptocephalus Costa & Brasil 1993 -- (Costa 1995:126 [ref. 22097], Costa 1998:238 [ref. 23578], Costa 1998:76 [ref. 23792], Lazara 2001:77 [ref. 25711], Costa 2001:372 [ref. 25719], Costa in Reis et al. 2003:529 [ref. 27061], Costa 2009:147 [ref. 30511], Costa 2014:80 [ref. 33510], Silva et al. 2020:14 [ref. 37809]). Current status: Valid as Cynolebias leptocephalus Costa & Brasil 1993. Rivulidae: Cynolebiinae. Distribution: South America: middle São Francisco River basin (Brazil). Habitat: freshwater.

leticia, Laimosemion Valdesalici [S.] 2016:280, Figs. 1-2 [Zootaxa 4085 (no. 2); ref. 34270] Swamp area near Leticia at km 13-14, Rio Tacana drainage, Rio Amazonas basin, Department of Amazonas, Colombia, 4°07'02"S, 69°57'6.4"W [correction received from the author], elevation 85 meters. Holotype: IAvH-P 12943. Paratypes: MSNG. Type catalog: DoNascimiento et al. 2016:427 [ref. 34787]. •Valid as Rivulus leticia (Valdesalici 2016) -- (Vermeulen 2023:109 [ref. 40177]). •Valid as Laimosemion leticia Valdesalici 2016 -- (DoNascimiento et al. 2017:101 [ref. 35633], Nielsen et al. 2022:42 [ref. 39106]). Current status: Valid as Laimosemion leticia Valdesalici 2016. Rivulidae: Rivulinae. Distribution: Upper Amazon River basin, Colombia. Habitat: freshwater.

leucurus, Rivulus Fowler [H. W.] 1944:244, Figs. 21-23 [Proceedings of the Academy of Natural Sciences of Philadelphia v. 96; ref. 1452] Río Juradó, Colombia, elevation 600 feet. Holotype: ANSP 71436. Paratypes: ANSP 71437-50 (14). Type catalog: Böhlke 1984:96 [ref. 13621]. •Status uncertain -- (Huber 1992:283 [ref. 20639]). •Valid as Rivulus leucurus Fowler 1944 -- (Lazara 2001:278 [ref. 25711], Costa in Reis et al. 2003:537 [ref. 27061], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys). •Valid as Cynodonichthys leucurus (Fowler 1944) -- (Costa 2011:242 [ref. 31655], DoNascimiento et al. 2017:101 [ref. 35633]). Current status: Valid as Cynodonichthys leucurus (Fowler 1944). Rivulidae: Rivulinae. Distribution: Pacific coastal basins, Colombia. Habitat: freshwater.

limnaeus, Austrofundulus transilis Schultz [L. P.] 1949:85, Fig. 10 [Proceedings of the United States National Museum v. 99 (no. 3235); ref. 3967] Lower Río Cocuiza, 15 kilometers west of San Félix, at western border of Falcón state, Venezuela. Holotype: UMMZ 141916. Paratypes: UMMZ 141917 (32, now 26, 8 c&s), USNM 122005 (6). Additional material: (2). •Valid as Austrofundulus limnaeus Schultz 1949 -- (Taphorn & Thomerson 1978:413 [ref. 4337], Parenti 1981:488 [ref. 7066], Murphy & Collier 1997:797 [ref. 25585], Costa 1998:80 [ref. 23792], Lazara 2001:57 [ref. 25711], Costa in Reis et al. 2003:527 [ref. 27061], Hrbek et al. 2005:22 [ref. 28063] with types from the Amazon basin not this species). Current status: Valid as Austrofundulus limnaeus Schultz 1949. Rivulidae: Rivulinae. Distribution: Lake Maracaibo basin Venezuela. Habitat: freshwater.

limoncochae, Rivulus Hoedeman [J. J.] 1962:146, Fig. 2 [Beaufortia v. 9 (no. 103); ref. 5929] Limoncocha, Río Napo tributary, rivulet emptying into lagoon, Ecuador. Holotype: ZMA 100339a. Paratypes: ZMA 100339b (2), 101504 (22). Type catalog: Nijssen et al. 1982:71 [ref. 19236]. •Valid as Rivulus limoncochae Hoedeman 1962 -- (Ovchynnyk 1967:40 [ref. 37559], Huber 1992:286 [ref. 20639], Lazara 2001:278 [ref. 25711], Costa in Reis et al. 2003:537 [ref. 27061], Costa 2006:139, 165 [ref. 28875] in subgenus Cynodonichthys, Valdesalici & Schindler 2011:313 [ref. 31673] subgenus Cynodonichthys, Barriga Salazar 2014:117 [ref. 35745]). •Valid as Anablepsoides limoncochae (Hoedeman 1962) -- (Costa 2011:243 [ref. 31655], Costa 2013:346 [ref. 32528], Valdesalici & Schindler 2013:296 [ref. 33109], Nielsen et al. 2016:76 [ref. 34406], Nielsen 2016:166 [ref. 34861], Valdesalici & Gil 2017:16 [ref. 35110], see DoNascimiento et al. 2017:[30] [ref. 35679], Valdesalici & Gil 2019:152 [ref. 37074], Nielsen et al. 2022:36 [ref. 39105]). Current status: Valid as Anablepsoides limoncochae (Hoedeman 1962). Rivulidae: Rivulinae. Distribution: South America: upper Amazon basin (Ecuador) endemic. Habitat: freshwater.

linearis, Melanorivulus Costa [W. J. E. M.] 2018:23, Figs. 6-7 [Zoosystematics and Evolution v. 94 (no. 1); ref. 35717] Córrego Água Limpa, upper Rio Pardo drainage, Rio Paraná basin, Bandeirantes municipality, Mato Grosso do Sul State, Brazil, 19°40'01"S, 54°18'13"W, elevation about 620 meters. Holotype: UFRJ 11678. Paratypes: CICCAA, UFRJ. •Valid as Melanorivulus linearis Costa 2018 -- (Volcan et al. 2018:275 [ref. 35895]). Current status: Valid as Melanorivulus linearis Costa 2018. Rivulidae: Rivulinae. Distribution: South America: middle Rio Paraná basin, central Brazilian Cerrado, Mato Grosso do Sul state, Brazil. Habitat: freshwater.

lineasoppilatae, Anablepsoides Valdesalici [S.] & Schindler [I.] 2013:296, Figs. 1-2 [Vertebrate Zoology v. 63 (no. 3); ref. 33109] Departamento Puno, Rio San Gaban drainage (13°27′21.4″S, 70°24′36.5″W), Peru. Holotype: MUSM 46995. Paratypes: MTD F 33003 (1), MSNG 57426 (5). Plus non-type specimens. •Valid as Anablepsoides lineasoppilatae Valdesalici & Schindler 2013 -- (Nielsen et al. 2016:76 [ref. 34406], Nielsen 2016:166 [ref. 34861], Valdesalici & Gil 2019:152 [ref. 37074]). Current status: Valid as Anablepsoides lineasoppilatae Valdesalici & Schindler 2013. Rivulidae: Rivulinae. Distribution: Rio San Gaban and Rio Araza drainages, upper Amazon basin, Peru. Habitat: freshwater.

litteratus, Rivulus Costa [W. J. E. M.] 2005:75, Figs. 6-7 [Neotropical Ichthyology v. 3 (no. 1); ref. 28192] Município de Alto córrego do Sapo, upper rio Araguaia basin, road MT-100, 31 kilometers south of Alto Araguaia, 17°33'38.5"S, 53°18'33"W, Estado de Mato grosso, Brazil, elevation 750 meters. Holotype: UFRJ 5956. Paratypes: MCP 36123 (10); MZUSP 73303 (15); UFRJ 5837 (41), 5957 (7), 5958 (6, c&s). •Valid as Rivulus litteratus Costa 2005 -- (Costa 2006:162 [ref. 28875] in subgenus Melanorivulus, Costa 2006:55 [ref. 28876], Costa 2008:85 [ref. 29717]). •Valid as Melanorivulus litteratus (Costa 2005) -- (Costa 2011:241 [ref. 31655], Costa 2012:217 [ref. 32292], Nielsen et al. 2016:87 [ref. 34407], Costa et al. 2016:270 [ref. 35405], Volcan et al. 2018:275 [ref. 35895]). Current status: Valid as Melanorivulus litteratus (Costa 2005). Rivulidae: Rivulinae. Distribution: Upper Araguaia River drainage, Brazil. Habitat: freshwater.

litzi, Austrolebias Costa [W. J. E. M.] 2006:80, Fig. 32 [Zootaxa No. 1213; ref. 28708] 2.5 kilometers from arroio Arenal, about 12 kilometers from Santa Maria, road BR-392, Rio Grande do Sul, Brazil. Holotype: UFRJ 6233. Paratypes: UFRJ 4488 (11), 4987 (191), 5017 (4, c&s), 5028 (36), 5029 (6, c&s). •Valid as Austrolebias litzi Costa 2006 -- (Bertaco et al. 2016:424 [ref. 34561], Volcan et al. 2017:151 [ref. 35644], Loureiro et al. 2018:11 [ref. 36240]). •Valid as Matilebias litzi (Costa 2006) -- (Alonso et al. 2023:9 [ref. 40292]). Current status: Valid as Matilebias litzi (Costa 2006). Rivulidae: Cynolebiinae. Distribution: South America: upper Jacuí River drainage, Laguna dos Patos system, Río Grande do Sul, Brazil. Habitat: freshwater.

longignatus, Simpsonichthys Costa [W. J. E. M.] 2008:156, Figs. 1-2 [Ichthyological Exploration of Freshwaters v. 19 (no. 2); ref. 29874] Seasonal swamp in the Pacoti River floodplains, road CE-040, about 25 kilometers from Fortaleza, 3°53'51"S, 38°24'13"W, Municépio de Aquiraz, Estado do Ceará, Brazil. Holotype: UFRJ 6614. Paratypes: UFRJ 6615 (9), 6616 (4, c&s). •Valid as Hypsolebias longignatus Costa 2008 -- (Costa 2011:221 [ref. 31654], Abrantes et al. 2020:306 [ref. 37698], Abrantes et al. 2023:558 [ref. 40706]). Current status: Valid as Hypsolebias longignatus (Costa 2008). Rivulidae: Cynolebiinae. Distribution: South America: swamp next to Rio Pacoti, an isolated coastal basin, Ceará (Brazil). Habitat: freshwater.

longipinnis, Pterolebias Garman [S.] 1895:142, Pl. 3 (fig. 14) [Memoirs of the Museum of Comparative Zoology v. 19 (pt 1); ref. 1538] Santarém, Amazon River basin, Pará, Brazil. Lectotype: USNM 120429 [ex MCZ 6829]. Paralectotypes: MCZ 6829 (5), 6831 (2); USNM 120429 [ex MCZ 6829] (1). Lectotype selected by Thomerson 1984:528 [ref. 20604]. •Valid as Pterolebias longipinnis Garman 1895 -- (Thomerson 1984:528 [ref. 20604], Huber 1995:19 [ref. 22880] as aff. longipinnis, Fernández & Butí 1996:255 [ref. 22775], Costa 1998:77 [ref. 23792], Britski et al. 1999:139 [ref. 24147], Lazara 2001:263 [ref. 25711], Costa in Reis et al. 2003:533 [ref. 27061], López et al. 2003:70 [ref. 27366], Schindler 2004:71 [ref. 28034], Menni 2004:86 [ref. 28131], Costa 2005:13 [ref. 28393], Koerber 2011:7 [ref. 31122], Koerber 2014:12 [ref. 33621], Sarmiento et al. 2014:187 [ref. 35004], Mirande & Koerber 2015:52 [ref. 35117], Calviño et al. 2016:11 [ref. 34699], Koerber et al. 2017:71 [ref. 35267], Loureiro et al. 2018:11 [ref. 36240], Drawert 2023:38 [ref. 40730]). Current status: Valid as Pterolebias longipinnis Garman 1895. Rivulidae: Rivulinae. Distribution: South America: Amazon River basin (Argentina, Bolivia, Brazil and Paraguay). Habitat: freshwater.

lopesi, Simpsonichthys Nielsen [D. T. B.], Shibatta [O. A.], Suzart [R. dos R.] & Martín [A. F.] 2010:52, Figs. 1-3 [Zootaxa No. 2452; ref. 30828] Locality of Javi, temporary pool near the riacho de Santana, rio São Francisco basin, 12°12'04.6"S, 43°39'27.8'W, City of Muquém de São Francisco, northeastern Brazil. Holotype: MZUSP 103102. Paratypes: MZUEL 5177 (13, 4 c&s); MZUSP 103103 (5). •Valid as Simpsonichthys lopesi Nielsen, Shibatta, Suzart & Martín 2010. •Valid as Hypsolebias lopesi Nielsen, Shibatta, Suzart & Martín 2010 -- (Costa 2011:221 [ref. 31654], Costa 2013:142 [ref. 33008], Nielsen et al. 2014:28 [ref. 33143], Nielsen et al. 2014:132 [ref. 33451], Silva et al. 2020:14 [ref. 37809]). Current status: Valid as Hypsolebias lopesi (Nielsen, Shibatta, Suzart & Martín 2010). Rivulidae: Cynolebiinae. Distribution: South America: Rio São Francisco basin (Brazil). Habitat: freshwater.

lourenciano, Austrolebias Volcan [M. V.], Barbosa [C.], Robe [L. J.] & Lanés [L. E. K.] 2021:95, Figs. 5-7 [Zootaxa 4965 (no. 1); ref. 38292] Temporary pool in the floodplain of Arroio Pinto, tributary of Arroio São Lourenço, close to the BR-116 highway, São Lourenço do Sul municipality, Laguna dos Patos system, Rio Grande do Sul State, Brazil, 31°20'50"S, 52°03'53"W. Holotype: MCP 5440. Paratypes: MCP. •Valid as Austrolebias lourenciano Volcan, Barbosa, Robe & Lanés 2021. •Valid as Garcialebias lourenciano (Volcan, Barbosa, Robe & Lanés 2021) -- (Alonso et al. 2023:13 [ref. 40292]). Current status: Valid as Garcialebias lourenciano (Volcan, Barbosa, Robe & Lanés 2021). Rivulidae: Cynolebiinae. Distribution: South America: temporary pools in the floodplain of the Arroio São Lourenço basin, Laguna dos Patos system, southeastern Brazil. Habitat: freshwater.

luelingi, Rivulichthys Meinken [H.] 1969:423, Fig. 4 [Bonner Zoologische Beiträge v. 20 (no. 4); ref. 7832] Río Chaparé, about 4 kilometers from village of Todos Santos, Rio Mamoré drainage, Depto. Cochabamba, eastern Bolivia. Holotype: ZFMK 2091. Paratypes: ZFMK 2092-95 and 2108-2144 (11). Type catalog: Busse 1984:221 [ref. 28342] (with holotype on Meinken 1966), Herder et al. 2010:125 [ref. 31087]. •Valid as Pterolebias luelingi (Meinken 1969) -- (Schindler 2004:71 [ref. 28034]). •Synonym of Pterolebias longipinnis Garman 1895 -- (Thomerson 1984:528 [ref. 20604], Lazara 2001:263 [ref. 25711], Costa in Reis et al. 2003:533 [ref. 27061], Costa 2005:13 [ref. 28393], Mirande & Koerber 2015:52 [ref. 35117], Koerber et al. 2017:71 [ref. 35267]). Current status: Synonym of Pterolebias longipinnis Garman 1895. Rivulidae: Rivulinae. Habitat: freshwater.

luelingi, Rivulus Seegers [L.] 1984:273, Fig. 1 [Zoologische Beiträge v. 28 (no. 2); ref. 17455] Rio Piraí near Joinville, Estado de Santa Catarina, about 26°30'S, 48°45'W, southeastern Brazil. Holotype: ZFMK 11671. Paratypes: BMNH 1983.6.9:14-15 (2); SMF 17585 (5); ZFMK 11672 (1), 11673-11682 (10); ZMB 31347 (3). Type catalog: Paepke & Seegers 1986:169 [ref. 19981], Herder et al. 2010:126 [ref. 31087]. •Valid as Rivulus luelingi Seegers 1984 -- (Costa 1991:582 [ref. 20033], Huber 1992:291 [ref. 20639], Lazara 2001:278 [ref. 25711], Costa in Reis et al. 2003:537 [ref. 27061], Costa 2004:105 [ref. 27824], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys, Costa 2007:176 [ref. 29203], Costa 2008:47 [ref. 29622] in subgenus Atlantirivulus, Costa 2008:135 [ref. 29871], Costa & Lanés 2009:94 [ref. 30256]). •Valid as Atlantirivulus luelingi (Seegers 1984) -- (Costa 2011:244 [ref. 31655], Reis et al. 2020:473 [ref. 38364], Volcan et al. 2024:97 [ref. 41345]). Current status: Valid as Atlantirivulus luelingi (Seegers 1984). Rivulidae: Rivulinae. Distribution: South America: Atlantic coastal plain rivers, southeastern Mata Atlantica (Brazil). Habitat: freshwater.

luitalimae, Anablepsoides Nielsen [D. T. B.] 2016:167, Figs. 1-2 [aqua, International Journal of Ichthyology v. 22 (no. 4); ref. 34861] Stream tributary to rio Madeira, near Porto Velho airport, Porto Velho, Rondônia, Brazil, 8°43'31.40"S, 63°54'33.44"W, elevation 84 meters. Holotype: ZUEC 13006. Paratypes: ZUEC. •Valid as Anablepsoides luitalimae Nielsen 2016 -- (Valdesalici & Gil 2017:17 [ref. 35110], Valdesalici & Gil 2019:152 [ref. 37074]). Current status: Valid as Anablepsoides luitalimae Nielsen 2016. Rivulidae: Rivulinae. Distribution: Rio Madeira basin, Rondônia, Brazil. Habitat: freshwater.

lulai, Hypsolebias Ramos [T. P. A.], Nielsen [D. T. B.], Abrantes [Y. G.], Lira [F. O.] & Lustosa-Costa [S. Y.] 2023:4, Figs. 1-2, 6 [Neotropical Ichthyology v. 21 (no. 3): e230068; ref. 40546] Capim Grosso Lagoon, Recanto II settlement, Trairi River basin, Lagoa Salgada Municipality, Rio Grande do Norte State, Brazil, 06°10'S, 35°31'W. Holotype: UFPB 14713. Paratypes: UFPB, UFRN. •Valid as Hypsolebias lulai Ramos, Nielsen, Abrantes, Lira & Lustosa-Costa 2023. Current status: Valid as Hypsolebias lulai Ramos, Nielsen, Abrantes, Lira & Lustosa-Costa 2023. Rivulidae: Cynolebiinae. Distribution: South America: pools in Lagoa Salgada Municipality, Trairi River drainage, Rio Grande do Norte State, Brazil. Habitat: freshwater.

lungi, Rivulus Berkenkamp [H. O.] 1984:14, Figs. 1-2 [Sondermitteilung Aquarienfreunde, Wilhelmshaven; ref. 19939] Southwest of Matoury, French Guiana, 4°54'N, 52°19'W. Holotype: SMF 18426. Paratypes: SMF 18428 (3). •Mention as Rivulus lungi Berkenkamp 1984 -- (Huber 1991:65 [ref. 19721]). •Doubtfully valid as Rivulus lungi Berkekamp 1984 -- (Huber 1992:294 [ref. 20639]). •Valid as Rivulus lungi Berkenkamp 1984 -- (Keith et al. 2000:28 [ref. 24547], Lazara 2001:279 [ref. 25711], Costa in Reis et al. 2003:537 [ref. 27061], Keith et al. 2006:137 [ref. 28851], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys, Costa 2010:84 [ref. 30788]). •Valid as Anablepsoides lungi (Berkenkamp 1984) -- (Costa 2011:243 [ref. 31655], Costa et al. 2013:292 [ref. 33108], Nielsen 2016:166 [ref. 34861]). Current status: Valid as Anablepsoides lungi (Berkenkamp 1984). Rivulidae: Rivulinae. Distribution: Atlantic coastal drainages, French Guiana. Habitat: freshwater, brackish.

luteoflammulatus, Cynolebias Vaz-Ferreira [R.], Sierra de Soriano [B.] & Scaglia de Paulete [S.] 1965:25, Pls. 5-6 [Comunicaciones Zoologicas del Museo de Historia Natural de Montevideo v. 8 (no. 102) (for 25 June 1964); ref. 9087] Temporary pool near Arroyo Valizas, 34°26'S, 53°46'W, Dept. of Rocha, Uruguay. Holotype: ZVC P.527. Paratypes: MHNM CI 1440 [ex ZVC P.784] (2), ZVC P.811 (1). Type catalog: Loureiro et al. 2016:413, 414 [ref. 35150]. •Valid as Cynolebias luteoflammulatus Vaz-Ferreira, Sierra de Soriano & Scaglia de Paulete 1965 -- (Malabarba 1989:159 [ref. 14217], Costa 1995:63 [ref. 22097], Costa 1999:301 [ref. 24229], Costa 1999:93 [ref. 24131]). •Valid as Austrolebias luteoflammulatus (Vaz-Ferreira, Sierra de Soriano & Scaglia de Paulete 1965) -- (Costa 1998:75 [ref. 23792], Lazara 2001:61 [ref. 25711], Costa & Cheffe 2001:180 [ref. 25851], Costa 2002:917 [ref. 26505], Costa in Reis et al. 2003:528 [ref. 27061], Costa 2009:188 [ref. 30417], Loureiro et al. 2011:341 [ref. 31392], Litz & Koerber 2014:30 [ref. 33622], Bertaco et al. 2016:424 [ref. 34561], Nión et al. 2016:42 [ref. 35565], Loureiro et al. 2018:11 [ref. 36240], Loureiro et al. 2023:169 [ref. 40506]). •Valid as Acantholebias luteoflammulatus (Vaz-Ferreira, Sierra de Soriano & Scaglia de Paulete 1965) -- (Alonso et al. 2023:11 [ref. 40292], Koerber et al. 2023:10 [ref. 40355]). Current status: Valid as Acantholebias luteoflammulatus (Vaz-Ferreira, Sierra de Soriano & Scaglia de Paulete 1965). Rivulidae: Cynolebiinae. Distribution: South America: Laguna dos Patos basin and adjacent southern coastal plains (Brazil and Uruguay). Habitat: freshwater.

luzardoi, Austrolebias Perujo [E.], Calviño [P. A.], Salvia [H.] & Prieto [F.] 2005:3, Figs. 1-6, 8 [Revista del Museo de La Plata Zool. v. 17 (no. 171); ref. 28452] Temporary swamp, 30°25'00"S, 56°27'03"W, near río Cuareim, tributary of río Uruguay, near Artigas, Uruguay. Holotype: MHNM 3200. Paratypes: MACN 8671 (2), 8672 (2); MHNM 3201 (14). Type catalog: Loureiro et al. 2016:412 [ref. 35150] •Synonym of Austrolebias periodicus (Costa 1999) -- (Costa 2006:83 [ref. 28708], Litz & Koerber 2014:30 [ref. 33622]). •Synonym of Matilebias periodicus (Costa 1999). Current status: Synonym of Matilebias periodicus (Costa 1999). Rivulidae: Cynolebiinae. Habitat: freshwater.

lyricauda, Rivulus Thomerson [J. E.], Berkenkamp [H. O.] & Taphorn [D. C.] 1991:290, Figs. 1-3 [Ichthyological Exploration of Freshwaters v. 1 (no. 4); ref. 19014] Small stream at Campamiento Canaima, tributary to Río Carrao, Río Caroni basin, Estado Bolivar, Venezuela, 6°15'N, 62°48'W. Holotype: MCNG 21715 (corrected by Huber from 21714). Paratypes: FMNH 99512 (5, 2 c&s); MBUCV-V-20275 (4, not 3), V-20280 (5, not 5); MCNG 21703 (1, c&s), 21715-16 (1, 5), 22120 (5), 23709-10 (2, 9), 27305 (20); MHNLS 282 (1), 286 (2); SMF 18435 (1), 18437 (1); ZSM 27957 (2). Type catalog: Huber 1992 [ref. 20639], Lasso et al. 1997:48 [ref. 23639], Provenzano et al. 1998:17 [ref. 24196], Neumann 2011:276 [ref. 31652]. Corrected in errata to SAM and ZSM types [Anonymous [ref. 33997]]. •Status uncertain -- (Huber 1992:298 [ref. 20639]). •Valid as Rivulus lyricauda Tomerson, Berkenkamp & Taphorn 1991 -- (Vermneulen & Isbrücker 2000:190 [ref. 25219], Lazara 2001:279 [ref. 25711], Costa in Reis et al. 2003:537 [ref. 27061], Radda 2004:21 [ref. 27638], Hrbek et al. 2004:570 [ref. 27910], Suijker & Collier 2006:10 [ref. 28729], Lasso-Alcalá et al. 2006:27 [ref. 28774], Costa 2006:153 [ref. 28875] in subgenus Laimosemion). •Valid as Laimosemion lyricauda (Thomerson, Berkenkamp & Taphorn 1991) -- (Costa 2011:239 [ref. 31655], Vermeulen et al. 2012:188 [ref. 32253]). Current status: Valid as Laimosemion lyricauda (Thomerson, Berkenkamp & Taphorn 1991). Rivulidae: Rivulinae. Distribution: Orinoco River basin, Venezuela. Habitat: freshwater.

mabelis, Cynolebias Hoetmer [J. W.] 1987:23 [Killi Nieuws v. 17 (no. 2); ref. 32544] •Appeared as nomen nudum -- (Lazara 2001:64 [ref. 25711] on Skillcorn 1988 [ref. 21419]). •As a synonym of Cynolebias affinis Amato 1986 -- (Reichert 1993:25 [ref. 33499]). •In the synonymy of Austrolebias affinis (Amato 1986) -- (Litz & Koerber 2014:29 [ref. 33622]). •In the synonymy of Matilebias affinis (Amato 1986). Nomen Nudum. Current status: Synonym of Matilebias affinis (Amato 1986). Rivulidae: Cynolebiinae.

mabura, Laimosemion Valdesalici [S.] & García Gil [J. R.] 2015:167, Fig. 1 [aqua, International Journal of Ichthyology v. 21 (no. 4); ref. 34010] Stream on the main track to Mahdia at the 10 miles point from Mabura Hill, Essequibo River drainage, central Guiana, 5°19.367'N, 58°48.951'W. Holotype: CSBD F1700. Paratypes: MSNG. •Valid as Laimosemion mabura Valdesalici & García Gil 2015 -- (Taphorn et al. 2022:37 [ref. 41297]). Current status: Valid as Laimosemion mabura Valdesalici & García Gil 2015. Rivulidae: Rivulinae. Distribution: South America: central Guyana endemic. Habitat: freshwater.

macaubensis, Simpsonichthys Costa [W. J. E. M.] & Suzart [R. dos R.] in Costa 2006:34, Figs. 7-8 [Zootaxa No. 1306; ref. 28771] Temporary pool near Macaúbas, rio Paramirim drainage, rio São Francisco basin, about 13°00'S, 42°30'W, Estado da Bahia, Brazil, elevation 680 meters. Holotype: UFRJ 6385. Paratypes: UFRJ 6105 (1), 6106 (12, c&s). •Valid as Simpsonichthys macaubensis Costa & Suzart 2006 -- (Costa 2007:100 [ref. 29445]). •Valid as Hypsolebias macaubensis (Costa & Suzart 2006) -- (Costa 2011:222 [ref. 31654], Costa et al. 2013:1 [ref. 32952], Britzke et al. 2016:134 [ref. 34461]). Current status: Valid as Hypsolebias macaubensis (Costa & Suzart 2006). Rivulidae: Cynolebiinae. Distribution: Paramirim River drainage, São Francico River basin, Bahia, Brazil. Habitat: freshwater.

macrophthalmus, Trigonectes Costa [W. J. E. M.] 1990:141, Fig. 11 [Ichthyological Exploration of Freshwaters v. 1 (no. 2); ref. 14542] Forte Príncipe da Beira, Rondônia, Brazil. Holotype: MNRJ 11308. Paratypes: MNRJ 9804 (35), 11309 (1); MZUSP 37190-91 (3, 9), 38453 (1, c&s), 38454 (1, c&s). •Valid as Trigonectes macrophthalmus Costa 1990 -- (Costa 1998:78 [ref. 23792], Lazara 2001:309 [ref. 25711], Costa in Reis et al. 2003:543 [ref. 27061]). Current status: Valid as Trigonectes macrophthalmus Costa 1990. Rivulidae: Rivulinae. Distribution: Guaporé River basin, Brazil. Habitat: freshwater.

maculatus, Cynolebias Steindachner [F.] 1881:98 [Anzeiger der Akademie der Wissenschaften in Wien, Mathematisch-Naturwissenschaftliche Klasse v. 18 (no. 11) (for 5 May 1881); ref. 20484] La Plata, Argentina. Holotype (unique): NMW 59613. Species illustrated and described in more detail in Steindachner 1881:10, Pl. 5 (figs. 3-3a) [ref. 14299]. •Synonym of Cynolebias bellottii Steindachner 1881 -- (Costa 1995:71 [ref. 22097]). •Synonym of Austrolebias bellotti (Steindachner 1881) -- (Lazara 2001:60 [ref. 25711], Costa in Reis et al. 2003:527 [ref. 27061], Costa 2006:104 [ref. 28708]). •Synonym of Austrolebias bellottii (Steindachner 1881) -- (Costa 2006:104 [ref. 28708], Mirande & Koerber 2015:51 [ref. 35117]). Current status: Synonym of Austrolebias bellottii (Steindachner 1881). Rivulidae: Cynolebiinae. Habitat: freshwater.

maculipinnis, Pterolebias Radda [A. C.] (ex Weibezahn) 1964:41, Fig. [Die Aquarien- und Terrarienzeitschrift (DATZ) v. 17 (no. 2); ref. 19907] Roadside pool in Rio Pao drainage, 9°16'15"N, 68°09'00"W, on road from Tinaco to el Baul, Cojedes, Venezuela. Neotype: FMNH 85267. Type catalog: Ibarra & Stewart 1987:72 [ref. 12367], Provenzano et al. 1998:19 [ref. 24196]. Neotype designated by Taphorn & Thomerson 1978:395 [ref. 4337]; Provenzano et al. 1998:19 [ref. 24196] indicate Weibezahn material is at MBUCV. See Taphorn & Thomerson 1978:395 [ref. 4337] for suggested authorship as Weibezahn, but the correct author is Radda [Weibezahn's manuscript not published]. •Valid as Rachovia maculipinnis (Radda 1964) -- (Taphorn & Thomerson 1978:394 [ref. 4337], Parenti 1981:486 [ref. 7066], Costa 1998:80 [ref. 23792], Lazara 2001:265 [ref. 25711], Costa in Reis et al. 2003:533 [ref. 27061], DoNascimiento et al. 2017:101 [ref. 35633], Loureiro et al. 2018:3 [ref. 36240], Urbano-Bonilla et al. 2018:73 [ref. 35773], Berkenkamp 2020:13 [ref. 37695]). Current status: Valid as Rachovia maculipinnis (Radda 1964). Rivulidae: Rivulinae. Distribution: Orinoco River basin, northwest Venezuela. Habitat: freshwater.

magdalenae, Rivulus Eigenmann [C. H.] & Henn [A. W.] in Henn 1916:109 [Annals of the Carnegie Museum v. 10 (nos 1-2) (art. 9); ref. 2093] Ibagué, Tolima Department, central Colombia, elevation 4250 feet [about 1300 meters]. Holotype: FMNH 56997 [ex CM 5813]. Paratypes and non-types: CAS 44227 (12) [ex CM 5814a-m; IU 13603]; FMNH 56998-99 (12, 8), 57000-02 (2, 8, 1); CAS 52234 [ex IU 13606] (6), 52235 [ex IU 13605] (2), 78377 [ex IU 13606] (6). Type catalog: Henn 1928:86 [ref. 12305], Ibarra & Stewart 1987:76 [ref. 12367] but non-types wrongly as types, Huber 1992 [ref. 20639]. •Valid as Rivulus magdalenae Eigenmann & Henn 1916 -- (Huber 1992:301 [ref. 20639], Lazara 2001:279 [ref. 25711], Costa in Reis et al. 2003:537 [ref. 27061], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys, Gomes 2023:9 [ref. 40174]). •Valid as Cynodonichthys magdalenae (Eigenmann & Henn 1916) -- (Costa 2011:242 [ref. 31655], DoNascimiento et al. 2017:101 [ref. 35633]). Current status: Valid as Cynodonichthys magdalenae (Eigenmann & Henn 1916). Rivulidae: Rivulinae. Distribution: South America: Magdalena and Cauca River basins, central Colombia; occurence in the Cauca River could be artificial. Habitat: freshwater.

magnificus, Cynolebias Costa [W. J. E. M.] & Brasil [G. C.] 1991:59, Figs. 5-6 [Ichthyological Exploration of Freshwaters v. 2 (no. 1); ref. 16651] Right bank plain of the Rio São Francisco, about 1 kilometer from the river channel, County of Manga, Minas Gerais State, Brazil. Holotype: MZUSP 41374. Paratypes: MZUSP 41375 (9). •Valid as Cynolebias magnificus Costa & Brasil 1991 -- (Costa 1995:53 [ref. 22097]). •Valid as Simpsonichthys magnificus (Costa & Brasil 1991) -- (Costa 1996:130 [ref. 25271], Costa 1998:75 [ref. 23792], Lazara 2001:297 [ref. 25711], Costa in Reis et al. 2003:541 [ref. 27061], Costa & Nielsen 2004:126 [ref. 27825], Costa 2006:17 [ref. 28620], Costa 2007:91 [ref. 29445], Costa 2010:77 [ref. 30777]). •Valid as Hypsolebias magnificus (Costa & Brasil 1991) -- (based on generic placement in Costa 2011 [ref. 31654], Costa 2013;141 [ref. 33008], Nielsen et al. 2014:28 [ref. 33143], Nielsen et al. 2014:132 [ref. 33451], Costa et al. 2018:155 [ref. 36034]). Current status: Valid as Hypsolebias magnificus (Costa & Brasil 1991). Rivulidae: Cynolebiinae. Distribution: Middle São Francisco River basin, Bahia and Minas Gerais states, Brazil. Habitat: freshwater.

mahdiaensis, Rivulus Suijker [W. H.] & Collier [G. E.] 2006:3, Figs. 1-3 [Zootaxa No. 1246; ref. 28729] Blackwater creek, tributary of Potaro River, on 5 miles from Mahdia crossing the road from Mahdia to Garroway Stream, 5°21'11'N, 59°08'48"W, Mazaruni-Potaro District, Guyana. Holotype: ZMA 123720. Paratypes: FMNH 113582-84 (1, 1, 1); ZMA 123721 (1), 123722 (1), 123853-55 (1, 1, 1). Combined with a neuter genus, the adjective should be mahdianense. •Valid as Rivulus mahdiaensis Suijker & Collier 2006 -- (Costa & Souza 2009:64 [ref. 30289], Schindler & Valdesalici 2011:109 [ref. 31382]). •Valid as Laimosemion mahdiaense (Suijker & Collier 2006) -- (Costa 2011:239 [ref. 31655] as mahdianensis, Vermeulen et al. 2012:188 [ref. 32253] as mahdianensis, Costa & Lazzarotto 2014:372 [ref. 33247] as mahdianensis, Valdesalici 2016:279 [ref. 34270] as mahdianensis, Taphorn et al. 2022:37 [ref. 41297]). Current status: Valid as Laimosemion mahdiaense (Suijker & Collier 2006). Rivulidae: Rivulinae. Distribution: South America: Mazaruni-Potaro District (Guyana) endemic. Habitat: freshwater.

manaensis, Rivulus Hoedeman [J. J.] 1961:61 [Bulletin of Aquatic Biology v. 2 (no. 17); ref. 19257] Creek to St. Patawa, Mana River, French Guiana. Holotype: ZMA 102252a. Paratypes: ZMA 102252b (3). Type catalog: Nijssen et al. 1982:71 [ref. 19236]. Combined with a neuter genus, the adjective should be manaense. •Synonym of Rivulus agilae Hoedeman 1954 -- (Huber 1992:87, 305 [ref. 20639], Huber 1999:50 [ref. 23834], Lazara 2001:270 [ref. 25711], Costa in Reis et al. 2003:534 [ref. 27061]). •Valid as Laimosemion manaense (Hoedeman 1961) -- (Costa 2011:239 [ref. 31655] as manaensis). •Synonym of Laimosemion agilae (Hoedeman 1954). Current status: Synonym of Laimosemion agilae (Hoedeman 1954). Rivulidae: Rivulinae. Habitat: freshwater.

manuensis, Aphyolebias Costa [W. J. E. M.] 2003:161, Fig. 2C [Comunicações do Museu de Ciências e Tecnologia da PUCRS, Sér. Zoologia. v. 16 (no. 2); ref. 27616] Cocha Cashu, Parque Nacional Manu, Río Madre de Dios basin, about 12°10'S, 71°45'W, Depart. Madre de Dios, Peru. Holotype: MUSM 20295. Paratypes: MUSM 3116 (3); UFRJ 5545 (2, c&s). •Valid as Aphyolebias manuensis Costa 2003 -- (Valdesalici et al. 2015:129 [ref. 33902]). •Valid as Moema manuensis (Costa 2003) -- (Valdesalici 2016:70 [ref. 34174]). Current status: Valid as Moema manuensis (Costa 2003). Rivulidae: Rivulinae. Distribution: Río Madre de Dios basin, Peru. Habitat: freshwater.

margaritatus, Simpsonichthys Costa [W. J. E. M.] 2012:314, Figs. 1-2 [Ichthyological Exploration of Freshwaters v. 22 (no. 4); ref. 31750] Floodplains of Verde River, a tributary of Paranaíba River, upper Paraná River basin, Municipío de Serranópolis, Estado de Goiás, Brazil. Holotype: UFRJ 8339. Paratypes: UFRJ 8340 (1), 8341 (1). •Valid as Simpsonichthys margaritatus Costa 2012 -- (Nielsen et al. 2017:166 [ref. 35304]). Current status: Valid as Simpsonichthys margaritatus Costa 2012. Rivulidae: Cynolebiinae. Distribution: Floodplains of the Verde River, upper Paraná River basin, central Brazil. Habitat: freshwater.

marginatus, Simpsonichthys Costa [W. J. E. M.] & Brasil [G. C.] 1996:94, Figs. 1-2 [Revue française d'Aquariologie Herpétologie v. 23 (no. 3/4); ref. 22917] Temporary pool near Rio dos Patos, tributary of Rio Maranhao, Rio Tocantins basin, Barro Alto, Goiás State, Brazil [ca. 15°00'S, 49°00'W]. Holotype: MNRJ 12440. Paratypes: MNRJ 12441 (1); MZUSP 50163 (2); UFRJ 3536 (7), 3537 (4, c&s). •Valid as Simpsonichthys marginatus Costa & Brasil 1996 -- (Costa 1998:75 [ref. 23792], Lazara 2001:298 [ref. 25711], Costa in Reis et al. 2003:541 [ref. 27061], Costa 2006:17 [ref. 28620], Costa 2007:116 [ref. 29445], Costa 2008:156 [ref. 29874], Costa 2008:156 [ref. 29874]). •Valid as Hypsolebias marginatus (Costa & Brasil 1996) -- (based on generic placement in Costa 2011 [ref. 31654]). Current status: Valid as Hypsolebias marginatus (Costa & Brasil 1996). Rivulidae: Cynolebiinae. Distribution: Rio dos Patos floodplain, Tocantins River basin, Goiás, central Brazil. Habitat: freshwater.

maricensis, Atlantirivulus Costa [W. J. E. M.] 2014:10, Figs. 1-2 [Vertebrate Zoology v. 64 (no. 1); ref. 33307] Estado do Rio de Janeiro, Município de Maricá: stream crossing the road to Ponta Negra, near the village of Bananal, Carangueijo river drainage, Maricá lagoon system, 22° 54′ 51″ S, 42° 43′ 17″ W, Brazil. Holotype: UFRJ 9822. Paratypes: UFRJ 6202 (23), 6303 (3), 8792 (17), 8793 (4), 8794 (3). Plus non-type specimens. •Valid as Atlantirivulus maricensis Costa 2014 Current status: Valid as Atlantirivulus maricensis Costa 2014. Rivulidae: Rivulinae. Distribution: Maricá lagoon system, Brazil. Habitat: freshwater.

marmoratus, Cynopoecilus Ladiges [W.] 1934:74, Fig. p. 73 [Das Aquarium: eine Zeitschrift mit Bildern für Liebhaber, Schulen und Naturfreunde, Berlin 1934 (no. 4); ref. 18445] Temporary pool in forest, rio Iguaçú basin, Vila de Cava, Rio de Janeiro State, Brazil, 22°39'30.0"S, 43°25'45.7"W. Neotype: MCP 28604. Also in Ladiges 1934:104 [ref. 20522], earliest not researched. Holotype not preserved, see Ladiges 1943:275 [ref. 36156]. Redescription and neotype designation by Costa 2002:380 [ref. 26544]. •Valid as Leptolebias marmoratus (Ladiges 1934) -- (Costa 1995:92 [ref. 22097], Costa 1998:73 [ref. 23792], Lazara 2001:193 [ref. 25711], Costa 2002:380 [ref. 26544], Costa in Reis et al. 2003:530 [ref. 27061], Costa 2008:156 [ref. 29596], Ferrer et al. 2014:847 [ref. 33589], Costa 2016:129 [ref. 34776]). Current status: Valid as Leptolebias marmoratus (Ladiges 1934). Rivulidae: Cynolebiinae. Distribution: Atlantic coastal river basins, southeastern Brazil. Habitat: freshwater.

marmoratus, Rivulus Poey [F.] 1880:248 [Anales de la Sociedad Española de Historia Natural, Madrid v. 9 (for 7 July 1880); ref. 6524] Cuba, if not from the USA. Neotype: USNM 37429. Non-types: USNM 123000 (1). Type catalog: Huber 1992 [ref. 20639], Faloh-Gandarilla et al. 2016:7 [ref. 35177]. Opinion 1798 (Case 2722) gives precedence to marmoratus over the specific name ocellatus Hensel 1868 when the 2 names are considered synonyms. Lectotype selected by Rivas 1945:45 [ref. 20642], but syntype status disputed in Smith & Lazara 1990:191 [ref. 20643]. Rivas lectotype established as neotype in Opinion 1798. •Synonym of Rivulus ocellatus Hensel 1868 -- (Huber 1992:308 [ref. 20639]). •Valid as Rivulus marmoratus Poey 1880 -- (Lee et al. 1980:536 [ref. 22416], Robins & Ray 1986:110 [ref. 23100], Page & Burr 1991:215 [ref. 18983], Cervigón 1991:209 [ref. 24472], Greenfield & Thomerson 1997:99 [ref. 22947], McEachran & Fechhelm 1998:892 [ref. 23897], Musick et al. 2000:13 [ref. 24959], Lazara 2001:279 [ref. 25711], Ghedotti & Wiley 2003:1146 [ref. 27019], Costa in Reis et al. 2003:537 [ref. 27061], Smith et al. 2003:15 [ref. 27621], Nelson et al. 2004:101 [ref. 27807], Miller 2006:207 [ref. 28615]). •Possibly valid in Cryptolebias -- (Costa 2004:115 [ref. 27763]). •Possibly valid in Kryptolebias -- (Costa 2004:107 [ref. 28584]). •Valid as Kryptolebias marmoratus (Poey 1880) -- (Costa 2006:6 [ref. 28624], Scharpf 2007:10 [ref. 30398], Matamoros et al. 2009:12 [ref. 31241], Page & Burr 2011:424 [ref. 31215], Costa 2011:186 [ref. 31358], Page et al. 2013:103 [ref. 32708], Phillip et al. 2013:21 [ref. 32896], Berbel-Filho et al. 2016:[1] [ref. 34830], Costa 2016:189 [ref. 34932], Faloh-Gandarilla et al. 2016:7 [ref. 35177], Lozano-Vilano & De la Maza-Benignos 2016:4 [ref. 35401], Loureiro et al. 2018:11 [ref. 36240], Robins et al. 2018:193 [ref. 35886], Carvalho-Filho 2023:94 [ref. 40480], Page et al. 2023:140 [ref. 40505]). Current status: Valid as Kryptolebias marmoratus (Poey 1880). Rivulidae: Kryptolebiatinae. Distribution: Antilles, southern North America, eastern coast of Central America and northern coast of South America; introduced elsewhere. Habitat: freshwater, brackish.

martinsi, Hypsolebias Britzke [R.], Nielsen [D. T. B.] & Oliveira [C.] 2016:129, Fig. 4 [Zootaxa 4114 (no. 2); ref. 34461] Ceará, Amontada, temporary pool near Rio Icaraizinho, Brazil, 3°11'4.72"S, 39°44'58.3"W, altitude 42 meters. Holotype: ZUEC 10791. Paratypes: LBP, ZUEC. •Valid as Hypsolebias martinsi Britzke, Nielsen & Oliveira 2016 -- (Abrantes et al. 2020:306 [ref. 37698], Abrantes et al. 2023:560 [ref. 40706]). Current status: Valid as Hypsolebias martinsi Britzke, Nielsen & Oliveira 2016. Rivulidae: Cynolebiinae. Distribution: South America: Rio Icaraizinho, Rio Mundaú and Rio Aracatiaçu drainages, Ceará (Brazil). Habitat: freshwater.

mazaruni, Rivulus Myers [G. S.] 1924:1 [American Museum Novitates No. 129; ref. 15457] Mutusi Hole, Mazaruni River, Guyana. Holotype: AMNH 8346. Paratypes: AMNH 8347 (5). •Status uncertain -- (Huber 1992:314 [ref. 20639]). •Valid as Rivulus mazaruni Myers 1924 -- (Lazara 2001:280 [ref. 25711], Costa in Reis et al. 2003:538 [ref. 27061], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys, Costa 2010:84 [ref. 30788], Vermeulen 2022:15 [ref. 39817]). •Valid as Anablepsoides mazaruni (Myers 1924) -- (Costa 2011:243 [ref. 31655], Costa et al. 2013:292 [ref. 33108], Nielsen 2016:166 [ref. 34861], Taphorn et al. 2022:36 [ref. 41297]). Current status: Valid as Anablepsoides mazaruni (Myers 1924). Rivulidae: Rivulinae. Distribution: South America: Essequibo River basin (Guyana) endemic. Habitat: freshwater.

mediopapillatus, Simpsonichthys Costa [W. J. E. M.] 2006:30, Figs. 4-6 [Zootaxa No. 1306; ref. 28771] Temporary pool, 8 kilometers south of Pindaí, rio São Domingos drainage, tributary to Rio Verde Pequeno, itself a trib to rio Verde Grande, rio São Francisco basin, 14°33'36.7"S. 42°42'09.8:W, Estado da Bahia, Brazil, elevation 628 meters. Holotype: UFRJ 5406. Paratypes: MCP 40139 (3); UFRJ 5407 (3, c&s), 5408 (9), 6064 (12), 6074 (4). •Valid as Simpsonichthys mediopapillatus Costa 2006 -- (Costa 2007:100 [ref. 29445]). •Valid as Hypsolebias mediopapillatus (Costa 2006) -- (Costa 2011:222 [ref. 31654], Costa et al. 2012:73 [ref. 31845], Costa et al. 2013:1 [ref. 32952], Nielsen et al. 2014:29 [ref. 33143], Britzke et al. 2016:134 [ref. 34461], Silva et al. 2020:14 [ref. 37809]). Current status: Valid as Hypsolebias mediopapillatus (Costa 2006). Rivulidae: Cynolebiinae. Distribution: South America: Rio Verde Grande drainage, São Francisco River basin (Bahia State, Brazil). Habitat: freshwater.

megaroni, Rivulus Costa [W. J. E. M.] 2010:366, Fig. 1 [Ichthyological Exploration of Freshwaters v. 20 (no. 4) [Dec. 2009]; ref. 30690] Stream crossing road BR-080, 7 kilometers east of the right bank of the Xingu River,about 10°43'S, 53°00'W, Parque Indígena do Xingu, Municipío de São José, Estado de Mato Grosso, Brazil. Holotype: UFRJ 6693. Paratypes: many at UFRJ. Plus non-type specimens. •Valid as Melanorivulus megaroni (Costa 2010) -- (Costa 2011:241 [ref. 31655], Costa et al. 2014:196 [ref. 33400], Costa 2016:135 [ref. 34900] dated 2009, Costa et al. 2016:270 [ref. 35405], Nielsen 2017:66 [ref. 35340], Nielsen & Britzke 2019:42 [ref. 36525]). Current status: Valid as Melanorivulus megaroni (Costa 2010). Rivulidae: Rivulinae. Distribution: Upper and middle Xingu River drainage, southern Amazon River basin, central Brazil. Habitat: freshwater.

mejiai, Rivulus Vermeulen [F. B. M.] 2020:39, Figs. 2-3, 5-6 [Killi-Data Series 2020; ref. 37941] Steep mountain creek, affluent to Rio Unete, westerly from the town Aguazul, Meta River basin, Departamento Casanare, Colombia, 5°12'28"N, 72°37'40"W, elevation 556 meters. Holotype: IAVHP 13654. Paratypes: IAVHP 13655 (9). Genus tentative. •Valid as Anablepsoides mejiai (Vermeulen 2020). Current status: Valid as Anablepsoides mejiai (Vermeulen 2020). Rivulidae: Rivulinae. Distribution: South America: Rio Unete drainage, Meta River basin, eastern Cordillera slopes of the Colombian Andes, Departamento Casanare, Colombia. Habitat: freshwater.

melanoorus, Cynolebias Amato [L. H.] 1986:4, Pl. 2 (figs. 3-4) [Comunicaciones Zoologicas del Museo de Historia Natural de Montevideo v. 11 (no. 162); ref. 9170] Floodlands of Tres Cruces Creek, route 5, kilometers 399.5, Tacuarembó, Uruguay, 31°39.11'S, 55°54.01'W. Holotype: MHNM 2545. Paratypes: MHNM 2546-48 (24, 1, 33). Type catalog: Loureiro et al. 2016:413 [ref. 35150]. •Valid as Cynolebias melanoorus Amato 1986 -- (Costa 1995:73 [ref. 22097]). •Valid as Austrolebias melanoorus (Amato 1986) -- (Costa 1998:75 [ref. 23792], Lazara 2001:62 [ref. 25711], Costa 2002:917 [ref. 26505], Calviño 2003:11 [ref. 26595], Costa in Reis et al. 2003:528 [ref. 27061], Loureiro et al. 2004:27 [ref. 27658], Costa 2006:97 [ref. 28708], Costa 2009:188 [ref. 30417], Loureiro et al. 2011:340 [ref. 31392], Lanés et al. 2014:17 [ref. 33234], Litz & Koerber 2014:30 [ref. 33622], Bertaco et al. 2016:424 [ref. 34561], Nión et al. 2016:43 [ref. 35565], Loureiro et al. 2018:11 [ref. 36240], Serra & Loureiro 2018:554 [ref. 36329], Volcan & Severo-Neto 2019:550 [ref. 36539], Alonso et al. 2023:10 [ref. 40292], Loureiro et al. 2023:168 [ref. 40506]). Current status: Valid as Austrolebias melanoorus (Amato 1986). Rivulidae: Cynolebiinae. Distribution: South America: Uruguay River basin (Uruguay) and Rio Grande do Sul (Brazil). Habitat: freshwater.

melanopterus, Melanorivulus Nielsen [D. T. B.] & Ohara [W. M.] 2024:333, Figs. 1-2 [Zootaxa 5496 (no. 3); ref. 41421] Conquista do Oeste, headwaters of rio Galera, tributary of the right bank of the upper rio Guaporé, Mato Grosso, Brazil, 14°30'4.98"S, 59°25'26.03"W, elevation 643 meters. Holotype: INPA 60664. Paratypes: CPUFMT 8596 (6), INPA 60665 (4), ZUEC 18282 (21). •Valid as Melanorivulus melanopterus Nielsen & Ohara 2024. Current status: Valid as Melanorivulus melanopterus Nielsen & Ohara 2024. Rivulidae: Rivulinae. Distribution: South America: upper rio Galera drainage, rio Guaporé basin, Mato Grosso State, Brazil. Habitat: freshwater.

melanotaenia, Cynolebias Regan [C. T.] 1912:506 [Annals and Magazine of Natural History (Series 8) v. 10 (no. 59); ref. 3648] Vila da Quinta, about 32°10'S, 52°20'W, Munic. de Rio Grande, Estado do Rio Grande do Sul, Brazil. Syntypes: BMNH 1909.9.5.15-22 (9). For information on type locality see Buckup & Malabarba 1990:103 [ref. 16740]. •Valid as Cynolebias melanotaenia Regan 1912 -- (Malabarba 1989:159 [ref. 14217]). •Valid as Cynopoecilus melanotaenia (Regan 1912) -- (Costa 1995:102 [ref. 22097], Costa 1998:74 [ref. 23792], Lazara 2001:79 [ref. 25711], Costa 2002:13 [ref. 26061], Costa in Reis et al. 2003:530 [ref. 27061], Ferrer et al. 2014:847 [ref. 33589], Litz & Koerber 2014:31 [ref. 33622], Costa et al. 2016:3 [ref. 34354], Bertaco et al. 2016:424 [ref. 34561], Costa 2016:130 [ref. 34776], Nión et al. 2016:43 [ref. 35565] with author as Regan 1912, Loureiro et al. 2018:11 [ref. 36240], Garcez et al. 2020:[3] [ref. 37602], Loureiro et al. 2023:172 [ref. 40506]). Current status: Valid as Cynopoecilus melanotaenia (Regan 1912). Rivulidae: Cynolebiinae. Distribution: South America: Atlantic coastal drainages (southern Brazil and Uruguay). Habitat: freshwater.

microphthalmus, Cynolebias Costa [W. J. E. M.] & Brasil [G. C.] in Costa 1995:81, Fig. 97 [Pearl killifishes. The Cynolebiatinae. Systematics and biogeography of the neotropical annual fish subfamily (Cyprinodontiformes: Rivulidae). 1995; ref. 22097] Mossoró, about 5°15'S, 37°20'W, Rio Grande do Norte, Brazil. Holotype: MZUSP 42312. Paratypes: MZUSP 38343 (3). Second author is G. C. Brasil. •Valid as Cynolebias microphthalmus Costa & Brasil 1995 -- (Costa 1998:238 [ref. 23578], Costa 1998:76 [ref. 23792], Lazara 2001:77 [ref. 25711], Costa 2001:354 [ref. 25719], Costa 2002:917 [ref. 26505], Costa in Reis et al. 2003:529 [ref. 27061], Costa 2009:147 [ref. 30511], Costa 2014:80 [ref. 33510], Abrantes et al. 2020:306 [ref. 37698]). Current status: Valid as Cynolebias microphthalmus Costa & Brasil 1995. Rivulidae: Cynolebiinae. Distribution: South America: Jaguaribe and Mossoró River basins, Rio Grande do Norte (Brazil). Habitat: freshwater.

micropus, Fundulus Steindachner [F.] 1863:184 [23] [Sitzungsberichte der Mathematisch-Naturwissenschaftlichen Classe der Kaiserlichen Akademie der Wissenschaften v. 48 (1. Abth.); ref. 4208] Rio Negro, Brazil. Holotype: NMW 77672. Paratypes if any: (none found). Type catalog: Huber 1992 [ref. 20639]. On p. 23 of separate. •Probably a synonym of Rivulus compressus Henn 1916 -- (Hrbek et al. 2004:569 [ref. 27910]). •Valid as Rivulus micropus (Steindachner 1863) -- (Ortega & Vari 1986:19 [ref. 9708], Huber 1991:67 [ref. 19721], Huber 1992:317 [ref. 20639], Lazara 2001:281 [ref. 25711], Costa in Reis et al. 2003:538 [ref. 27061], Costa 2006:145 [ref. 28875], Costa 2006:139, 145 [ref. 28875] in subgenus Cynodonichthys). •Valid as Anablepsoides micropus (Steindachner 1863) -- (Costa 2011:243 [ref. 31655]). Current status: Valid as Anablepsoides micropus (Steindachner 1863). Rivulidae: Rivulinae. Distribution: Middle Amazon River basin, Brazil. Habitat: freshwater.

milesi, Rivulus Fowler [H. W.] 1941:9, Figs. 10-11 [Notulae Naturae (Philadelphia) No. 73; ref. 13236] Honda, Colombia. Holotype: ANSP 69337 (with paratypes). Paratypes: ANSP 69338-42 (5). Type catalog: Böhlke 1984:96 [ref. 13621]. •Synonym of Rivulus magdalenae Eigenmann & Henn 1916 -- (Huber 1992:321 [ref. 20639], Lazara 2001:279 [ref. 25711], Costa in Reis et al. 2003:537 [ref. 27061], Gomes 2023:17 [ref. 40174]). •Synonym of Cynodonichthys magdalenae (Eigenmann & Henn 1916). Current status: Synonym of Cynodonichthys magdalenae (Eigenmann & Henn 1916). Rivulidae: Rivulinae. Habitat: freshwater.

minimus, Cynolebias Myers [G. S.] 1942:109 [Stanford Ichthyological Bulletin v. 2 (no. 4); ref. 3121] Cane brake along the road to Rio, 1 mile east of Itaquahy [Itaguaí], Rio de Janeiro State, Brazil. Holotype: CAS-SU 36525. Paratypes: CAS-SU 36526 (4). Type catalog: Böhlke 1953:52 [ref. 12291]. •Valid as Cynolebias minimus Myers 1942 -- (Costa 1988:558 [ref. 14540]). •Valid as Leptolebias minimus (Myers 1942) -- (Costa 1995:88 [ref. 22097], Costa 1998:73 [ref. 23792], Lazara 2001:194 [ref. 25711], Costa in Reis et al. 2003:531 [ref. 27061]). •Valid as Notholebias minimus (Myers 1942) -- (Costa 2008:157 [ref. 29596], Costa & Amorim 2013:67 [ref. 32799], Ferrer et al. 2014:847 [ref. 33589], Costa 2016:128 [ref. 34776], Guedes et al. 2023:6 [ref. 40380]). Current status: Valid as Notholebias minimus (Myers 1942). Rivulidae: Cynolebiinae. Distribution: South America: Atlantic coastal river basins (Rio de Janeiro, Brazil). Habitat: freshwater.

minuano, Austrolebias Costa [W. J. E. M.] & Cheffe [M. M.] 2001:185, Figs. 4-5 [Comunicações do Museu de Ciências da PUCRS, Série Zoologia v. 14 (no. 2); ref. 25851] Temporary lagoon about 4.5 kilometers north of Quinta, Rio Grande do Sul, Brazil. Holotype: MCP 28028. Paratypes: MCP 28029 (8); MUCP 3622 (21), UFRJ 5032 (8), 5036 (33), 5037 (4, 2 c&s). •Valid as Austrolebias minuano Costa & Cheffe 2001 -- (Costa in Reis et al. 2003:528 [ref. 27061], Loureiro et al. 2004:27 [ref. 27658], Costa 2006:124 [ref. 28708], Volcan et al. 2014:170 [ref. 33543], Bertaco et al. 2016:424 [ref. 34561], Costa et al. 2017:142 [ref. 35626], Loureiro et al. 2018:11 [ref. 36240], Fernandes et al. 2020:[3] 3 [ref. 38700], Volcan et al. 2021:104 [ref. 38292]). •Valid as Garcialebias minuano (Costa & Cheffe 2001) -- (Alonso et al. 2023:13 [ref. 40292]). Current status: Valid as Garcialebias minuano (Costa & Cheffe 2001). Rivulidae: Cynolebiinae. Distribution: South America: Laguna dos Patos system, southeastern Brazil. Habitat: freshwater.

modestus, Rivulus Costa [W. J. E. M.] 1991:329, Figs. 1 A-B [Revista Brasileira de Biologia v. 51 (no. 2); ref. 20644] Rio Mutum, lower Rio Tapajós basin, Municipio Comodoro, Mato Grosso, Brazil. Holotype: MNRJ 11670. Paratypes: MNRJ 11671 (5). •Valid as Melanorivulus modestus (Costa 1991) -- (Costa 2016:128 [ref. 34900], Nielsen 2017:65 [ref. 35340], Nielsen & Britzke 2019:41 [ref. 36525], Nielsen & Ohara 2024:339 [ref. 41421]). Current status: Valid as Melanorivulus modestus (Costa 1991). Rivulidae: Rivulinae. Distribution: South America: upper Juruena River drainage, Tapajós River basin, Mato Grosso, Brazil. Habitat: freshwater.

monikae, Rivulus Berkenkamp [H. O.] & Etzel [V.] 1995:1, Figs. [Deutsche Killifisch Gemeinschaft Journal v. 27 (no. 1); ref. 22656] Coclé Province, 15 kilometers north of La Pintada, central Panama, 8°40'N, 80°40'W. Holotype: SMF 18451. Paratypes: SMF 18452 (3), 18456 (2). •Valid as Rivulus monikae Berkenkamp & Etzel 1995 -- (Lazara 2001:281 [ref. 25711], Costa in Reis et al. 2003:538 [ref. 27061], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys). •Valid as Cynodonichthys monikae (Berkenkamp & Etzel 1995) -- (Costa 2011:242 [ref. 31655]). Current status: Valid as Cynodonichthys monikae (Berkenkamp & Etzel 1995). Rivulidae: Rivulinae. Distribution: Caribbean river drainages, Panama. Habitat: freshwater.

monstrosus, Cynolebias Huber [J. H.] 1995:9, Fig. 4, col. pl. (middle fig.) [Killi-Contact - Périodique bimestriel Spec. publ.; ref. 22880] Near La Serena, Boqueron Dept., 21.94°S, 56.97°W, Paraguay. Holotype: MNHN 1994-1110. Paratypes: ANSP 169973 (2), 169974 (orig. 2, now 1), 169975 (orig. 2, now 1); MNHN 1993-3619 [ex ANSP 169975] (1), 1994-1111 (1); MNHNP [ex ANSP 169974] (1); NMW 92899 (1); ZMA 121281 (3), 121284-85 (4, 2). Appeared as above first, then in Huber 1995 (Nov.):110, Figs. 9-12 [ref. 22204]. •Valid as Megalebias monstrosus (Huber 1995) -- (Costa 1998:76 [ref. 23792], Lazara 2001:204 [ref. 25711], Costa 2002:917 [ref. 26505], Costa in Reis et al. 2003:531 [ref. 27061], López et al. 2003:70 [ref. 27366], Menni 2004:86 [ref. 28131]). •Valid as Austrolebias monstrosus (Huber 1995) -- (Costa 2006:54 [ref. 28708], Koerber 2011:7 [ref. 31122], Lanés et al. 2014:17 [ref. 33234], Koerber 2014:11 [ref. 33621], Sarmiento et al. 2014:187 [ref. 35004], Mirande & Koerber 2015:51 [ref. 35117], Alonso et al. 2016:6 [ref. 34643], Koerber et al. 2017:70 [ref. 35267], Loureiro et al. 2018:11 [ref. 36240]). •Valid as Titanolebias monstrosus (Huber 1995) -- (Alonso et al. 2023:12 [ref. 40292], Koerber et al. 2023:4 [ref. 40368], Drawert 2023:17 [ref. 40730], Koerber 2024:6 [ref. 41228]). Current status: Valid as Titanolebias monstrosus (Huber 1995). Rivulidae: Cynolebiinae. Distribution: South America: semi-arid Chaco Region (Argentina, Paraguay and Bolivia). Habitat: freshwater.

monticola, Rivulus Staeck [W.] & Schindler [I.] 1997:372, Figs. 1-3 [Ichthyological Exploration of Freshwaters v. 7 (no. 4); ref. 22749] Small brook on eastern slopes of the Cordilleria de Allcuquiro, 2°39'N, 78°13'W, Moreno-Santiago Province, Ecuador. Holotype: ZMB 32681. Paratypes: ZMB 32682-83 (11, 1). •Valid as Rivulus monticola Staeck & Schindler 1997 -- (Lazara 2001:281 [ref. 25711], Costa in Reis et al. 2003:538 [ref. 27061], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys, Barriga Salazar 2014:117 [ref. 35745]). •Valid as Anablepsoides monticola (Staeck & Schindler 1997) -- (Costa 2011:243 [ref. 31655]). Current status: Valid as Anablepsoides monticola (Staeck & Schindler 1997). Rivulidae: Rivulinae. Distribution: Amazon River basin, Ecuador. Habitat: freshwater.

montium, Rivulus Hildebrand [S. F.] 1938:319, Fig. 9 [Field Museum of Natural History, Publications, Zoölogical Series v. 22 (no. 4); ref. 12363] Hillside trickle between Río Boquerón and Río Pequeni, Chagres basin, Panama. Holotype: MCZ 34880. Paratypes: FMNH 36661-62 (2), MCZ 61984 [ex MCZ 34880] (2), USNM 109119 (2). Additional material: (22) MCZ 34656 (6 or 8), USNM 78871 (9). Type catalog: Ibarra & Stewart 1987:76 [ref. 12367], Huber 1992 [ref. 20639]. •Possible synonym of Rivulus brunneus Meek & Hildebrand 1913 -- (Huber 1992:136 [ref. 20639], Etzel & Berkenkamp 1992:30 [ref. 32437]). •Valid as Rivulus montium Hildebrand 1938 -- (Berkenkamp & Etzel 1997:125 [ref. 23735], Lazara 2001:281 [ref. 25711], Costa in Reis et al. 2003:538 [ref. 27061], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys). •Valid as Cynodonichthys montium (Hildebrand 1938) -- (Costa 2011:242 [ref. 31655]). Current status: Valid as Cynodonichthys montium (Hildebrand 1938). Rivulidae: Rivulinae. Distribution: Central America: Atlantic river basins (Panama). Habitat: freshwater.

multipapillatus, Cynopoecilus Costa [W. J. E. M.] 2002:22, Fig. 6 [Ichthyological Exploration of Freshwaters v. 13 (no. 1); ref. 26061] Temporary pool between road RS-787 and lagoa da Fortaleza, about 30°10'S, 50°15'W, Rio Grande do Sul, Brazil. Holotype: MCP 26933. Paratypes: MCP 26934 (10), UFRJ 5232 (40), 5233 (8, 4 c&s). •Valid as Cynopoecilus multipapillatus Costa 2002 -- (Costa in Reis et al. 2003:530 [ref. 27061], Ferrer et al. 2014:847 [ref. 33589], Bertaco et al. 2016:424 [ref. 34561]). •Synonym of Cynopoecilus fulgens Costa 2002 -- (Costa 2016:130 [ref. 34776]). Current status: Synonym of Cynopoecilus fulgens Costa 2002. Rivulidae: Cynolebiinae. Habitat: freshwater.

multiradiatus, Cynolebias Costa [W. J. E. M.] & Brasil [G. C.] 1994:1, Figs. 1-2 [Revue française d'Aquariologie Herpétologie v. 21 (no. 1/2); ref. 21597] Temporary pool at Brejinho de Nazar, Tocantins, Brazil, about 10°59'S, 48°38'W, elevation 247 meters. Holotype: MNRJ 12519. Paratypes: MNRJ 12520 (9); MZUSP 46080 (8); UFRJ 2074-76 (7, 6, 8). •Valid as Simpsonichthys multiradiatus (Costa & Brasil 1994) -- (Costa 1996:130 [ref. 25271], Costa 1998:75 [ref. 23792], Lazara 2001:298 [ref. 25711], Costa 2003:52 [ref. 26768], Costa in Reis et al. 2003:541 [ref. 27061], Costa 2006:17 [ref. 28620], Costa 2007:126 [ref. 29445], Costa 2008:156 [ref. 29874], Nielsen et al. 2010:57 [ref. 30828]). •Valid as Hypsolebias multiradiatus (Costa & Brasil 1994) -- (based on generic placement in Costa 2011 [ref. 31654], Nielsen et al. 2012:69 [ref. 32283]). Current status: Valid as Hypsolebias multiradiatus (Costa & Brasil 1994). Rivulidae: Cynolebiinae. Distribution: Middle Tocantins River floodplians, Tocantins, Brazil. Habitat: freshwater.

myersi, Austrofundulus Dahl [G.] 1958:42 [Stanford Ichthyological Bulletin v. 7 (no. 3); ref. 12064] Semi-permanent pond at Sincelejo, northern Colombia. Holotype: CAS-SU 49513. Paratypes: (many, plus allotype) CAS-SU 49513 (orig. 10, now 7), 68324 (1, c&s), DZVU [ex CAS-SU 49513] (1). Appeared first in Dahl 1958:30 [ref. 19187] if date of 18 June is correct for ref. 19187. •Synonym of Austrofundulus limnaeus Schultz 1949 -- (Taphorn & Thomerson 1978:414 [ref. 4337], Costa in Reis et al. 2003:527 [ref. 27061]). •Valid as Austrofundulus myersi Dahl 1958 -- (Lazara 2001:57 [ref. 25711], Hrbek et al. 2005:31 [ref. 28063], DoNascimiento et al. 2017:101 [ref. 35633]). Current status: Valid as Austrofundulus myersi Dahl 1958. Rivulidae: Rivulinae. Distribution: Lower Magdalena River, Colombia. Habitat: freshwater.

myersi, Cynolebias Carvalho [A. L. de] 1971:401, Figs. 1-3 [Revista Brasileira de Biologia v. 31 (no. 3); ref. 7669] Temporary pool, northeast coastal plain of Espírito Santo State, 18 kilometers from Conceiçao da Barra, Brazil, 18°25'34"S, 39°43'00"W [floodplains of the Velha Antônia creek, near the west entrance to the village of Itaúnas]. Holotype: MNRJ 9849. Paratypes: MNRJ 9850-51 (1, 53). •Valid as Cynolebias myersi Carvalho 1971 -- (Costa 1995:44 [ref. 22097]). •Valid as Nematolebias myersi (Carvalho 1971) -- (Costa 1998:75 [ref. 23792], Lazara 2001:213 [ref. 25711]). •Valid as Simpsonichthys myersi (Carvalho 1971) -- (Costa 1996:130 [ref. 25271], Costa 2002:41 [ref. 26064], Costa in Reis et al. 2003:541 [ref. 27061], Costa 2006:16 [ref. 28620], Costa 2007:8 [ref. 29445]). •Valid as Xenurolebias myersi (Carvalho 1971) -- (Costa & Amorim 2014:355 [ref. 33343], Silva et al. 2020:15 [ref. 37809], Vieira-Guimarães et al. 2024:55 [ref. 41258]). Current status: Valid as Xenurolebias myersi (Carvalho 1971). Rivulidae: Cynolebiinae. Distribution: South America: seasonal pools between Doce creek and Velha Antônia creek, Espiritu Santo and Bahia (Brazil). Habitat: freshwater.

myersi, Rivulus Hubbs [C. L.] 1936:210, Pl. 2 (figs. 1-2) [Carnegie Institution of Washington Publications No. 457 (art. 17); ref. 2247] 3 kilometers south of Progreso, Yucatán, Mexico. Holotype: UMMZ 102140. Paratypes: UMMZ 102141 (1). Type catalog: Huber 1992 [ref. 20639]. •Valid as Rivulus myersi Hubbs 1936 -- (Castro-Aguirre et al. 1999:216 [ref. 24550]). •Synonym of Rivulus tenuis (Meek 1904) -- (Huber 1992:330 [ref. 20639], Lazara 2001:285 [ref. 25711], Costa in Reis et al. 2003:539 [ref. 27061]). •Valid as Cynodonichthys myersi (Hubbs 1936) -- (Costa 2011:242 [ref. 31655]). •Synonym of Cynodonichthys tenuis Meek 1904. Current status: Synonym of Cynodonichthys tenuis Meek 1904. Rivulidae: Rivulinae. Habitat: freshwater.

nachtigalli, Austrolebias Costa [W. J. E. M.] & Cheffe [M. M.] in Costa 2006:133, Fig. 50 [Zootaxa No. 1213; ref. 28708] Arroio Grande, road BR-116, about 32°15'S, 53°05'W, Rio Grande do Sul, Brazil. Holotype: UFRJ 6183. Paratypes: Many lots at CIMC and UFRJ. Plus non-type material. •Valid as Austrolebias nachtigalli Costa & Cheffe 2006 -- (Loureiro & García 2008:10 [ref. 30099] with question, Volcan et al. 2014:169 [ref. 33543], Bertaco et al. 2016:424 [ref. 34561], Costa et al. 2017:142 [ref. 35626] as natchigalli, Loureiro et al. 2018:11 [ref. 36240], Volcan et al. 2021:104 [ref. 38292]). •Valid as Garcialebias nachtigalli (Costa & Cheffe 2006) -- (Alonso et al. 2023:13 [ref. 40292]). Current status: Valid as Garcialebias nachtigalli (Costa & Cheffe 2006). Rivulidae: Cynolebiinae. Distribution: South America: Laguna dos Patos system, southeastern Brazil. Habitat: freshwater.

nanus, Cynolebias Da Cruz [C. A. G.] & Peixoto [O. L.] 1983:90, Figs. 1-3 [Arquivos da Universidade Federal Rural do Rio de Janeiro v. 6 (no. 1); ref. 8235] Between villages of Cava and Tinguá, Nova Iguaçú, 22°38'S, 43°25'W, Rio de Janeiro, Brazil. Holotype: MNRJ 10621. Paratypes: (12) MNRJ uncat. [ex CAGC 114.1/7] (7), uncat. [ex CAGC 115.1/2] (2), MNRJ 10622 (1); MZUSP 25229/30 (2). Original not seen. •Synonym of Leptolebias fluminensis (Faria & Muller 1937) -- (Costa 1995:91 [ref. 22097]). •Synonym of Leptolebias opalescens (Myers 1942) -- (Lazara 2001:194 [ref. 25711], Costa in Reis et al. 2003:531 [ref. 27061], Costa 2008:155 [ref. 29596]). •Synonym of Leptopanchax opalescens (Myers 1942). Current status: Synonym of Leptopanchax opalescens (Myers 1942). Rivulidae: Cynolebiinae. Habitat: freshwater.

nelsoni, Melanorivulus Deprá [G. C.], Pains da Silva [H.] & da Graça [W. J.] 2017:113, Figs. 1-2 [Zootaxa 4300 (no. 1); ref. 35503] Unnamed creek tributary to the córrego Beleza, tributary to the rio São Lourenço (rio Paraguai basin), municipality of Juscimeira, Mato Grosso, Brazil, 16°10'57"S, 55°0'40"W. Holotype: MCP 50981. Paratypes: NUP. Type catalog: Oliveira et al. 2022:34 [ref. 39255]. •Valid as Melanorivulus nelsoni Deprá, Pains da Silva & da Graça 2017. Current status: Valid as Melanorivulus nelsoni Deprá, Pains da Silva & da Graça 2017. Rivulidae: Rivulinae. Distribution: South America: Rio São Lourenço drainage, upper Rio Paraguai basin (Mato Grosso, Brazil). Habitat: freshwater.

nicoi, Rivulus Thomerson [J. E.] & Taphorn [D. C.] 1992:380, Fig. 4 [Ichthyological Exploration of Freshwaters v. 3 (no. 4); ref. 20003] Small forest pools about 500 meters from right bank of Río Ventuari, 4°16'N, 66°23'W, Orinoco drainage, Venezuela. Holotype: MCNG 23891. Paratypes: FMNH 100958 (2); MCNG 23892-93 (1, 1). •Valid as Rivulus nicoi Thomerson & Taphorn 1992 -- (Huber 1999:50 [ref. 23834], Lazara 2001:281 [ref. 25711], Costa in Reis et al. 2003:538 [ref. 27061], Costa 2006:153 [ref. 28875] in subgenus Laimosemion, Schindler & Valdesalici 2011:109 [ref. 31382] in subgenus Owiyeye). •Valid as Laimosemion nicoi (Thomerson & Taphorn 1992) -- (Costa 2011:239 [ref. 31655]). Current status: Valid as Laimosemion nicoi (Thomerson & Taphorn 1992). Rivulidae: Rivulinae. Distribution: Orinoco River basin, Venezuela. Habitat: freshwater.

nielseni, Simpsonichthys Costa [W. J. E. M.] 2005:58, Figs. 1-2 [Zootaxa No. 1039; ref. 28575] Temporary pool in Pirapora, São Francisco Rver floodplains, 17°21'59.6"S, 44°56'32.3"W, Estado de Minas Gerais, Brazil, elevation 500 meters. Holotype: UFRJ 6060. Paratypes: MCP 37306 (2); UFRJ 6061 (7), 6062 (5, c&s). •Valid as Simpsonichthys nielseni Costa 2005 -- (Costa 2006:17 [ref. 28620], Costa 2007:64 [ref. 29445]). •Valid as Hypsolebias nielseni (Costa 2005) -- (based on generic placement in Costa 2011 [ref. 31654]). Current status: Valid as Hypsolebias nielseni (Costa 2005). Rivulidae: Cynolebiinae. Distribution: Middle São Francisco River floodplains, Minas Gerais State, Brazil. Habitat: freshwater.

nigripinnis, Cynolebias Regan [C. T.] 1912:508 [Annals and Magazine of Natural History (Series 8) v. 10 (no. 59); ref. 3648] Río de la Plata, Argentina. Holotype (unique): BMNH 1909.4.2.29. •Valid as Cynolebias nigripinnis Regan 1912 -- (Costa 1995:67 [ref. 22097], Costa 1999:301 [ref. 24229], Fuller et al. 1999:292 [ref. 25838]). •Valid as Austrolebias nigripinnis (Regan 1912) -- (Costa 1998:75 [ref. 23792], Lazara 2001:62 [ref. 25711], Costa 2002:917 [ref. 26505], López et al. 2003:69 [ref. 27366], Menni 2004:86 [ref. 28131], Calviño 2005:15 [ref. 28325], Calviño 2006:183 [ref. 28679], Costa 2006:67 [ref. 28708], Calviño 2007:22 [ref. 29117], Costa 2009:188 [ref. 30417], Litz & Koerber 2014:30 [ref. 33622], Mirande & Koerber 2015:51 [ref. 35117], Alonso et al. 2016:5 [ref. 34643], Calviño et al. 2016:10 [ref. 34699], Nión et al. 2016:43 [ref. 35565], Volcan et al. 2017:387 [ref. 35260], Koerber et al. 2017:70 [ref. 35267], Volcan et al. 2017:151 [ref. 35644], Loureiro et al. 2018:11 [ref. 36240], Jamandre 2023:166 [ref. 40455], Loureiro et al. 2023:165 [ref. 40506]). •Valid as Argolebias nigripinnis (Regan 1912) -- (Alonso et al. 2023:7 [ref. 40292], Koerber et al. 2023:10 [ref. 40355], Koerber et al. 2023:4 [ref. 40368], Alonso et al. 2024:304 [ref. 40863], Koerber 2024:6 [ref. 41228]). Current status: Valid as Argolebias nigripinnis (Regan 1912). Rivulidae: Cynolebiinae. Distribution: South America: lower Paraná and Uruguay River basins (Argentina, Paraguay, Uruguay and Brazil). Introduced in the Philippines. Habitat: freshwater.

nigrofasciatus, Austrolebias Costa [W. J. E. M.] & Cheffe [M. M.] 2001:187, Figs. 6-7 [Comunicações do Museu de Ciências da PUCRS, Série Zoologia v. 14 (no. 2); ref. 25851] Temporary pool in Pontal da Barra, praia de Laranjal, Pelotas, Rio Grande do Sul, Brazil. Holotype: MCP 21172. Paratypes: MCP 21173 (6); MUCP 2561 (5); UFRJ 4014 (7 c&s), 4015 (26), 4016 (9), 4218 (11), 4219 (19), 4259 (13), 5343 (15). •Valid as Austrolebias nigrofasciatus Costa & Cheffe 2001 -- (Costa in Reis et al. 2003:528 [ref. 27061], Lourerio et al. 2004:27 [ref. 27658], Costa 2006:129 [ref. 28708], Loureiro & García 2008:6 [ref. 30099], Volcan et al. 2014:169 [ref. 33543], Bertaco et al. 2016:424 [ref. 34561], Costa et al. 2017:142 [ref. 35626], Loureiro et al. 2018:11 [ref. 36240], Volcan et al. 2021:104 [ref. 38292]). •Valid as Garcialebias nigrofasciatus (Costa & Cheffe 2001) -- (Alonso et al. 2023:13 [ref. 40292]). Current status: Valid as Garcialebias nigrofasciatus (Costa & Cheffe 2001). Rivulidae: Cynolebiinae. Distribution: South America: Laguna dos Patos system, southeastern Brazil. Habitat: freshwater.

nigromaculatus, Simpsonichthys Costa [W. J. E. M.] 2007:200, Figs. 1-2 [Ichthyological Exploration of Freshwaters v. 18 (no. 3); ref. 29338] Temporary swamp, near the road GO-050, Chapadão do Céu, 18°33'02.0"S, 52°37'43.1"W, Floodplains of rio da Prata, rio Aporé drainage, upper rio Paraná basin, Estado de Goiás, Brazil, elevation 778 meters. Holotype: UFRJ 6467. Paratypes: UFRJ 6468 (5), 6469 (3, c&s), 6473 (2). •Valid as Simpsonichthys nigromaculatus Costa 2007 -- (Costa 2007:31 [ref. 29445], Costa 2012:314 [ref. 31750], Nielsen et al. 2017:166 [ref. 35304], Nielsen et al. 2017:166 [ref. 35304]). Current status: Valid as Simpsonichthys nigromaculatus Costa 2007. Rivulidae: Cynolebiinae. Distribution: Prata River floodplains, Aporé River drainage, upper Paraná River basin, Goiás, Brazil. Habitat: freshwater.

nigromarginatus, Melanorivulus Costa [W. J. E. M.] 2018:21, Figs. 4-5 [Zoosystematics and Evolution v. 94 (no. 1); ref. 35717] Córrego Lajeado, Rio Corrente drainage, upper Rio Paraná basin, road GO-178, Itarumã municipality, Goiás State, Brazil, 18°49'45"S, 51°22'55"W, elevation about 470 meters. Holotype: UFRJ 8434. Paratypes: CICCAA, UFRJ. •Valid as Melanorivulus nigromarginatus Costa 2018 -- (Volcan et al. 2018:275 [ref. 35895]). Current status: Valid as Melanorivulus nigromarginatus Costa 2018. Rivulidae: Rivulinae. Distribution: South America: upper Rio Paraná basin, central Brazilian Cerrado, Brazil. Habitat: freshwater.

nigropunctatus, Melanorivulus Volcan [M. V.], Klotzel [B.] & Lanés [L. E. K.] 2017:83, Figs. 1-3 [Zootaxa 4236 (no. 1); ref. 35156] Municipality of Aqua Clara, stream tributary of left margin of Rio Verde, Mato Grosso do Sul State, Brazil, 20°02'29"S, 53°9'42"W, altitude 361 meters. Holotype: MCP 50017. Paratypes: MCP. •Valid as Melanorivulus nigropunctatus Volcan, Klotzel & Lanés 2017 -- (Volcan et al. 2018:275 [ref. 35895]). Current status: Valid as Melanorivulus nigropunctatus Volcan, Klotzel & Lanés 2017. Rivulidae: Rivulinae. Distribution: Rio Verde drainage, Rio Paraná basin, Mato Grosso do Sul state, Brazil. Habitat: freshwater.

nigrovittatus, Cynopoecilus Costa [W. J. E. M.] 2002:20, Fig. 5 [Ichthyological Exploration of Freshwaters v. 13 (no. 1); ref. 26061] Rio Caí flood-plains, about 29°45'S, 51°30'W, Montenegro, Rio Grande do Sul, Brazil. Holotype: MCP 26931. Paratypes: MCP 26932 (10); UFRJ 4820 (30), 4829 (43), 4976 (45), 4977 (23), 5012 (6, 2 c&s), 5039 (46), 5231 (6, 2 c&s). •Valid as Cynopoecilus nigrovittatus Costa 2002 -- (Costa in Reis et al. 2003:530 [ref. 27061], Ferrer et al. 2014:847 [ref. 33589], Costa et al. 2016:5 [ref. 34354], Bertaco et al. 2016:424 [ref. 34561], Costa 2016:130 [ref. 34776], Garcez et al. 2020:[3] [ref. 37602], Giora & Wingert 2023:28 [ref. 41026]). Current status: Valid as Cynopoecilus nigrovittatus Costa 2002. Rivulidae: Cynolebiinae. Distribution: South America: Lower Jacui River basin, Laguna dos Patos system (Brazil). Habitat: freshwater.

nioni, Cynolebias Berkenkamp [H. O.], Reichert [J. J.] & Prieto [F.] 1997:30, Fig. [Aquaristik aktuell (Germany) v. 5 (no. 3); ref. 23147] Highway 26 at kilometer 331, 32°10'S, 55°15'E, Tacuarembó, northeastern Uruguay. Holotype: SMF 18457. Paratypes: MNHNM (5) and (6); SMF 18458-59 (4, 3). •Synonym of Austrolebias vazferreirai (Berkenkamp, Etzel, Reichert & Salvia 1994) -- (Costa 2006:34 [ref. 28708], Litz & Koerber 2014:31 [ref. 33622]). •Synonym of Austrolebias robustus (Günther 1883) -- (Koerber et al. 2017:7 [ref. 35083], Koerber et al. 2017:8 [ref. 35632]). •Valid as Austrolebias nioni (Berkenkamp, Reichert & Prieto 1997) -- (Costa 1998:75 [ref. 23792], Lazara 2001:62 [ref. 25711], Costa 2002:917 [ref. 26505], Calviño 2003:11 [ref. 26595], Costa in Reis et al. 2003:528 [ref. 27061], Costa et al. 2004:15 [ref. 27657], Nión et al. 2016:43 [ref. 35565]). •Synonym of Austrolebias cinereus (Amato 1986) -- (García et al. 2019:[9] [ref. 36487]). •Synonym of Cypholebias cinereus (Amato 1986). Current status: Synonym of Cypholebias cinereus (Amato 1986). Rivulidae: Cynolebiinae. Habitat: freshwater.

nitens, Hypsolebias Costa [W. J. E. M.] in Costa, Amorim & Mattos 2012:79, Figs. 4, 12 [Systematics and Biodiversity v. 10 (no. 1); ref. 31845] Seasonal lagoon in floodplains of lower Verde River, a right tributary of middle São Francisco River, about 30 km north of the town of Itaguaçu, 10°43'20"S, 42°20'30"W, Bahia State, Brazil, elevation 414 meters. Holotype: UFRJ 8289. Paratypes: BMNH 2011.11.17.9-11 (3); UFRJ 6852 (3), 6853 (12), 8288 (4, c&s). •Valid as Hypsolebias nitens Costa 2012 -- (Costa et al. 2013:1 [ref. 32952], Britzke et al. 2016:134 [ref. 34461], Loureiro et al. 2018:11 [ref. 36240], Silva et al. 2020:14 [ref. 37809]). Current status: Valid as Hypsolebias nitens Costa 2012. Rivulidae: Cynolebiinae. Distribution: South America: lower Rio Verde basin, São Francisco River system (Bahia State, Brazil). Habitat: freshwater.

nonoiuliensis, Cynolebias Taberner [R.], Fernández-Santos [J. O.] & Castelli [J. O.] 1974:187, Fig. [Physis, Sección B (Las Aguas Continentales y sus Organismos) v. 33 (no. 87); ref. 7542] Temporary swamps, Nueve de Julio, Province Buenos Aires, Argentina. Holotype: MACN 6754 (no. 5). Paratypes: MACN 4241 (1), 6754 (11), 6755 (17). Type catalog: Braga & Piacentino 1994:103 [ref. 23697]. •Valid as Cynolebias nonoiuliensis Taberner, Fernández-Santos & Castelli 1974 -- (Costa 1995:69 [ref. 22097]). •Valid as Austrolebias nonoiuliensis (Taberner, Fernandez-Santos & Castelli 1974) -- (Costa 1998:75 [ref. 23792], Lazara 2001:63 [ref. 25711], Costa 2002:917 [ref. 26505], Calviño 2003:10 [ref. 26595], Costa in Reis et al. 2003:528 [ref. 27061], López et al. 2003:69 [ref. 27366], Costa et al. 2004:15 [ref. 27657], Menni 2004:86 [ref. 28131], Calviño 2005:15 [ref. 28325], Calviño 2006:183 [ref. 28679], Costa 2006:41 [ref. 28708], Costa 2011:100 [ref. 31504], Mirande & Koerber 2015:51 [ref. 35117], Loureiro et al. 2018:11 [ref. 36240], García et al. 2019:[12] [ref. 36487]). •Synonym of Austrolebias robustus (Günther 1883) -- (Koerber et al. 2017:7 [ref. 35083], Koerber et al. 2017:8 [ref. 35632]). •Synonym of Cypholebias robustus (Günther 1883) -- (Alonso et al. 2023:12 [ref. 40292]). Current status: Synonym of Cypholebias robustus (Günther 1883). Rivulidae: Cynolebiinae. Habitat: freshwater.

notabilis, Cynopoecilus Ferrer [J.], Wingert [J. M.] & Malabarba [L. R.] 2014:850, Figs. 2-7 [Zoological Journal of the Linnean Society v. 172; ref. 33589] Rio Grande do Sul, Município of Viamão, Águas Claras, rio Gravataí basin, laguna dos Patos system, temporary pool on wildlife reserve ‘Refúgio de Vida Silvestre Banhado dos Pachecos’, Brazil, 30°05′52″S, 50°51′05″W. Holotype: UFRGS 16300. Paratypes: MCP, UFRGS. •Valid as Cynopoecilus notabilis Ferrer, Wingert & Malabarba 2014 -- (Costa et al. 2016:6 [ref. 34354], Bertaco et al. 2016:425 [ref. 34561], Costa 2016:130 [ref. 34776] in subgenus Poecilopanchax, Garcez et al. 2020:[3] [ref. 37602]). Current status: Valid as Cynopoecilus notabilis Ferrer, Wingert & Malabarba 2014. Rivulidae: Cynolebiinae. Distribution: South America: Rio Gravataí basin, Laguna dos Patos system (Brazil). Habitat: freshwater.

notatus, Cynolebias Costa [W. J. E. M.], Lacerda [M. T. C.] & Brasil [G. C.] 1990:10, Figs. 1-2 [Revue française d'Aquariologie Herpétologie v. 17 (no. 1); ref. 16652] Temporary lagoon, Munic. de Alvorada do Norte, Estados de Goiás, Brazil, 14°30'S, 46°42'W. Holotype: MZUSP 39985. Paratypes: MNHN 0000-3251 (2), MNRJ 11559 (2), MZUSP 39986 (3), plus additional non-type material. •Valid as Cynolebias notatus Costa, Lacerda & Brasil 1990 -- (Costa 1995:50 [ref. 22097]). •Valid as Simpsonichthys notatus (Costa, Lacerda & Brasil 1990) -- (Costa 1996:130 [ref. 25271], Costa 1998:75 [ref. 23792], Costa & Hellner 1999:91 [ref. 23864], Lazara 2001:298 [ref. 25711], Costa in Reis et al. 2003:541 [ref. 27061], Costa & Brasil 2004:2 [ref. 28012], Costa 2005:63 [ref. 28575], Costa 2006:17 [ref. 28620], Costa 2007:66 [ref. 29445]). •Valid as Hypsolebias notatus (Costa, Lacerda & Brasil 1990) -- (based on generic placement in Costa 2011 [ref. 31654], Nielsen et al. 2014:132 [ref. 33451]). Current status: Valid as Hypsolebias notatus (Costa, Lacerda & Brasil 1990). Rivulidae: Cynolebiinae. Distribution: Upper Tocantins River basin, Goiás, Brazil. Habitat: freshwater.

nubium, Austrolebias Lanés [L. E. K.], Volcan [M. V.] & Maltchik [L.] 2021:507, Figs. 5-8, 9C-D [Zootaxa 4949 (no. 3); ref. 38189] Rio Santana, a tributary of upper rio Taquari-Antas drainage, upper rio Jacuí basin, Laguna dos Patos hydrographic system, Bom Jesus municipality, Rio Grande do Sul, Brazil, 28°37'00"S, 50°26'42"W, elevation 1,061 meters. Holotype: MCP 54457. Paratypes: MCP. •Valid as Austrolebias nubium Lanés, Volcan & Maltchik 2021. •Valid as Garcialebias nubium (Lanés, Volcan & Maltchik 2021) -- (Alonso et al. 2023:13 [ref. 40292]). Current status: Valid as Garcialebias nubium (Lanés, Volcan & Maltchik 2021). Rivulidae: Cynolebiinae. Distribution: South America: grassland pools of upper rio Taquari-Antas drainage, upper rio Jacuí basin, Rio Grande do Sul State, southern Brazil. Habitat: freshwater.

nudifrontata, Moema Costa [W. J. E. M.] 2003:168, Fig. 1 [Comunicações do Museu de Ciências e Tecnologia da PUCRS, Sér. Zoologia. v. 16 (no. 2); ref. 27617] Rio Branco floodplains near ilha do Carneiro, about 1°30'N, 61°10'W, Estado de Roraima, Brazil. Holotype: MCP 30684. MCP 30685 (3); UFRJ 248 (7), 262 (4), 283 (1, c&s), 5546 (2?). •Valid as Moema nudifrontata Costa 2003 -- (Valdesalici et al. 2015:129 [ref. 33902], Valdesalici 2016:66 [ref. 34174], Taphorn et al. 2022:37 [ref. 41297] as cf. nudifrontata). Current status: Valid as Moema nudifrontata Costa 2003. Rivulidae: Rivulinae. Distribution: South America: Roraima (Brazil). Habitat: freshwater.

nudiorbitatus, Hypsolebias Costa [W. J. E. M.] 2011:222, Figs. 1-2, 3a, 4a [Ichthyological Exploration of Freshwaters v. 22 (no. 3) [for Sept.]; ref. 31654] Seasonal swamp adjacent to das Jacas Creek, upper Itapicuru River basin, near road BA-381, about 2.5 km from Filadélfia village, 11°22'51"S, 40°00'51"W, Município de Filadélfia, Bahia, Brazil, elevation 415 meters. Holotype: UFRJ 6837. Paratypes: UFRJ 6838 (3, c&s), 6839 (1). •Valid as Hypsolebias nudiorbitatus Costa 2011 -- (Costa et al. 2012:73 [ref. 31845], Costa et al. 2013:1 [ref. 32952], Britzke et al. 2016:134 [ref. 34461], Silva et al. 2020:14 [ref. 37809], Abrantes et al. 2023:549 [ref. 40706], Vieira-Guimarães et al. 2024:54 [ref. 41258]). Current status: Valid as Hypsolebias nudiorbitatus Costa 2011. Rivulidae: Cynolebiinae. Distribution: South America: floodplains of the upper Itapicuru River drainage, Bahia State (Brazil). Habitat: freshwater.

nudiventris, Rivulus Costa [W. J. E. M.] & Brasil [G. C.] 1991:380, Figs. 3-4 [Ichthyological Exploration of Freshwaters v. 1 (no. 4); ref. 13612] Swamp on right bank of Rio Itapemirim, about 2 kilometers from the sea, County of Itapemirim, Espírito Santo, Brazil. Holotype: MZUSP 40283. Paratypes: MNRJ 11740 (2, c&s), MZUSP 40284 (3). •Status uncertain -- (Huber 1992:333 [ref. 20639]). •Valid as Rivulus nudiventris Costa & Brasil 1991 -- (Costa 1991:582 [ref. 20033], Lazara 2001:282 [ref. 25711], Costa in Reis et al. 2003:538 [ref. 27061], Costa 2004:105 [ref. 27824], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys, Costa 2007:128 [ref. 29225], Costa 2008:47 [ref. 29622] in subgenus Atlantirivulus, Costa 2008:135 [ref. 29871], Costa & Lanés 2009:94 [ref. 30256]). •Valid as Atlantirivulus nudiventris (Casta & Brasil 1991) -- (Costa 2011:244 [ref. 31655], Costa 2014:19 [ref. 33307], Vieira-Guimarães et al. 2024:54 [ref. 41258]). Current status: Valid as Atlantirivulus nudiventris (Costa & Brasil 1991). Rivulidae: Rivulinae. Distribution: South America: Itapemerim River floodplains (Brazil). Habitat: freshwater.

obliquoseriata, Pituna Costa [W. J. E. M.] 2007:16, Fig. 10 [Zootaxa No. 1410; ref. 28993] Road MT-326, 15-16 kilometers from right ban of rio das Mortes, rio Araguaia basin, about 14°00'S, 51°40'W, Estado de Mato Grosso, Brazil. Holotype: UFRJ 6398. Paratypes: MCP 40498 (3); UFRJ 247 (21), 294 (1), 3543 (11), 3545 (3, c&s). •Valid as Pituna obliquoseriata Costa 2007. Current status: Valid as Pituna obliquoseriata Costa 2007. Rivulidae: Rivulinae. Distribution: Temporary swamp near das Mortes River, Araguaía River basin, central Brazil. Habitat: freshwater.

obliquus, Pterolebias Costa [W. J. E. M.], Sarmiento [J.] & Barrera [S.] 1996:92, Fig. 1 [Ichthyological Exploration of Freshwaters v. 7 (no. 1); ref. 22215] Río Mamoré basin, temporary swamp associated with Arroyo Curiraba, Estación Biológica Beni, Depto. del Beni, Bolivia. Holotype: CBF 2328. Paratypes: CBF 2278-81 (5, 8, 13, 25); MZUSP 48347 (2); UFRJ 3034 (4), 3035 (2, c&s). Specific name is an adjective. •Valid as Aphyolebias obliquus (Costa, Sarmiento & Barrera 1996) -- (Costa 1998:78 [ref. 23792], Lazara 2001:5 [ref. 25711], Costa in Reis et al. 2003:526 [ref. 27061], Costa 2003:156 [ref. 27616], Sarmiento et al. 2014:187 [ref. 35004]). •Valid as Moema obliqua (Costa, Sarmiento & Barrera 1996) -- (Valdesalici et al. 2015:129 [ref. 33902] as obliquus, Valdesalici 2016:66 [ref. 34174] as obliquus, Drawert 2022:13 [ref. 39805], Drawert 2023:33 [ref. 40730]). Current status: Valid as Moema obliqua (Costa, Sarmiento & Barrera 1996). Rivulidae: Rivulinae. Distribution: South America: Mamoré River basin (Bolivia). Habitat: freshwater.

obscurus, Cynolebias Costa [W. J. E. M.] 2014:83, Fig. 2 [Ichthyological Exploration of Freshwaters v. 25 (no. 1); ref. 33510] Temporary pools next to road BA-156, about 6 km southeast of the town of Macaúbas, Paramirim river drainage, São Francisco River basin, 13°03'10"S, 42°36'58"W, Brazil., elevation 554 meters Holotype: UFRJ 9320. Paratypes: UFRJ 6774 (1), 6775 (8), 9321 (3). •Valid as Cynolebias obscurus Costa 2014 -- (Silva et al. 2020:14 [ref. 37809]). Current status: Valid as Cynolebias obscurus Costa 2014. Rivulidae: Cynolebiinae. Distribution: South America: Paramirim River drainage, São Francisco River basin (Brazil). Habitat: freshwater.

obscurus, Rivulus Garman [S.] 1895:140 [Memoirs of the Museum of Comparative Zoology v. 19 (pt 1); ref. 1538] Lago Hyanuary, Amazonas, Brazil. Lectotype: MCZ 6853. Paralectotypes: MCZ 98664 [ex MCZ 6853] (2). Lectotype selected in Huber 1992:336 [ref. 20639]. Rivulus ornatus and R. obscurus were described by Garman in the same publication; they are regarded as synonyms by some recent authors -- first reviser [Costa 1993] chose ornatus. •Valid as Rivulus obscurus Garman 1895 -- (Huber 1992:336 [ref. 20639], Lazara 2001:282 [ref. 25711], Hrbek et al. 2004:569 [ref. 27910], Vermeulen & Hrbek 2005:7 [ref. 28142]). •Synonym of Rivulus ornatus Garman 1895 -- (Costa in Reis et al. 2003:538 [ref. 27061], Costa 2006:147 [ref. 28875], Costa & Lazzarotto 2008:130 [ref. 29870]). •Synonym of Anablepsoides ornatus (Garman 1895) Current status: Synonym of Anablepsoides ornatus (Garman 1895). Rivulidae: Rivulinae. Distribution: South America: Middle Amazon River basin, Brazil [if valid]. Habitat: freshwater.

ocellatus, Rivulus Hensel [R.] 1868:365 [Archiv für Naturgeschichte v. 34 (pt 1); ref. 14075] Rio de Janeiro, Brazil. Holotype (unique): ZMB 7448. Type catalog: Paepke & Seegers 1986:169 [ref. 19981]. Name suppressed in Opinion 1798 (Case 2722) where it is ruled that Rivulus marmoratus Poey 1880 takes precedence over Rivulus ocellatus when both are considered synonyms. •Synonym of Rivulus marmoratus Poey 1880 -- (Lazara 2001:279 [ref. 25711]). •Valid as Rivulus ocellatus Hensel 1868 -- (Huber 1991:65 [ref. 19721], Huber 1992:340 [ref. 20639], Keith et al. 2000:46 [ref. 24547], Costa in Reis et al. 2003:538 [ref. 27061], Radda 2004:21 [ref. 27638], DoNascimiento 2016:537 [ref. 34727]). •Synonym of Cryptolebias marmoratus (Poey 1880) -- (Costa 2004:115 [ref. 27763]). •Valid as Kryptolebias ocellatus (Hensel 1868) -- (Costa 2004:107 [ref. 28584], Costa 2006:7 [ref. 28624], Keith et al. 2006:137 [ref. 28851], Costa 2011:185 [ref. 31358], Berbel-Filho et al. 2016:[1] [ref. 34830], Costa 2016:187 [ref. 34932], Carvalho-Filho 2023:94 [ref. 40480], Vieira-Guimarães et al. 2024:55 [ref. 41258]). Current status: Valid as Kryptolebias ocellatus (Hensel 1868). Rivulidae: Kryptolebiatinae. Distribution: South America: estuarine mangrove areas of Atlantic coast (eastern and south-eastern Brazil). Habitat: freshwater, brackish.

ocellatus, Simpsonichthys Costa [W. J. E. M.], Nielsen [D. T. B.] & de Luca [A. C.] 2001:25, Fig. [Aquarium (Brasil) v. 4 (no. 26); ref. 25934] Temporary pool in floodplain of Río Jequitinhonha, 1 kilometer west of Itaobim, road BR-367, Minas Geraís State, Brazil [ca. 16°40'S, 41°40'W, elevation about 270 m]. Holotype: MZUSP 61232. Paratypes: MZUSP 61233 (20); UFRJ 5096-97 (9, 60), 5098 (8, c&s), 5099-5102 (4, 38, 52, 208); UMMZ uncat. (24). Also appeared as new with description in Costa & Nielsen 2001:5 [ref. 26580]; earliest not determined. •Valid as Simpsonichthys ocellatus Costa, Nielsen & de Luca 2001 -- (Costa in Reis et al. 2003:542 [ref. 27061], Costa & Brasil 2004:2 [ref. 28012], Costa 2006:17 [ref. 28620], Costa 2007:56 [ref. 29445]). •Valid as Hypsolebias ocellatus (Costa, Nielsen & de Luca 2001) -- (based on generic placement in Costa 2011 [ref. 31654], Vieira-Guimarães et al. 2024:55 [ref. 41258]). Current status: Valid as Hypsolebias ocellatus (Costa, Nielsen & de Luca 2001). Rivulidae: Cynolebiinae. Distribution: South America: middle Jequitinhonha River floodplains, Minas Gerais State (Brazil). Habitat: freshwater.

ochraceus, Cynolebias Costa [W. J. E. M.] 2014:81, Fig. 1 [Ichthyological Exploration of Freshwaters v. 25 (no. 1); ref. 33510] Temporary pool about 12 km west from the town of Bom Jesus da Lapa, road BR-349, 13°15'42"S. 43°31'28"W, São Francisco River Basin, Brazil, elevation 437 meters. Holotype. Paratypes: UFRJ, ZFMK. Plus additional non-type material. •Valid as Cynolebias ochraceus Costa 2014 -- (Silva et al. 2020:14 [ref. 37809]). Current status: Valid as Cynolebias ochraceus Costa 2014. Rivulidae: Cynolebiinae. Distribution: South America: near road BR-349, São Francisco River basin (Brazil). Habitat: freshwater.

ofaie, Melanorivulus Volcan [M. V.], Klotzel [B.] & Lanés [L. E. K.] 2017:87, Figs. 5-7 [Zootaxa 4236 (no. 1); ref. 35156] Municipality of Ribas do Rio Pardo, stream tributary of right margin of Rio Verde, Mato Grosso do Sul State, Brazil, 20°25'27"S, 52°56'34"W, altitude 347 meters. Holotype: MCP 50019. Paratypes: MCP, ZUFMS-PIS. •Valid as Melanorivulus ofaie Volcan, Klotzel & Lanés 2017 -- (Volcan et al. 2018:275 [ref. 35895]). Current status: Valid as Melanorivulus ofaie Volcan, Klotzel & Lanés 2017. Rivulidae: Rivulinae. Distribution: South America: upper Rio Verde drainage, Paraná River basin, Mato Grosso do Sul State, Brazil. Habitat: freshwater.

opalescens, Cynolebias Myers [G. S.] 1942:107 [Stanford Ichthyological Bulletin v. 2 (no. 4); ref. 3121] Base of Serra do Petrópolis, near Imbarié, Município de Duque de Caxias, about 22°36'S, 43°12'W, Rio de Janeiro State, Brazil. Holotype: CAS-SU 36521. Paratypes: CAS-SU 36522 (9). Type catalog: Böhlke 1953:53 [ref. 12291]. Conserved over the senior subjective synonym Cynopoecilus fluminensis Faria & Muller 1937 in Opinion 1762. Now treated as valid; Leptolebias fluminensis is on the Official Index. •Synonym of Leptolebias fluminensis (Faria & Muller 1937) -- (Costa 1995:91 [ref. 22097]). •Valid as Cynolebias opalescens Myers 1942 -- (Da Cruz & Peixoto 1983:89, 90, 93 [ref. 8235]). •Valid as Leptolebias opalescens (Myers 1942) -- (Lazara 2001:194 [ref. 25711], Costa 2002:383 [ref. 26544], Costa in Reis et al. 2003:531 [ref. 27061], Costa 2008:154 [ref. 29596] as probably extinc, Costa 2013:357 [ref. 32567] not extinct, Ferrer et al. 2014:847 [ref. 33589]). •Valid as Leptopanchax opalescens (Myers 1942) -- (Costa 2016:128 [ref. 34776], Costa 2019:82 [ref. 36869], Guedes et al. 2020:2 [ref. 37981]). Current status: Valid as Leptopanchax opalescens (Myers 1942). Rivulidae: Cynolebiinae. Distribution: South America: Atlantic coastal river basins (Brazil). Habitat: freshwater.

ophiomimus, Rivulus Huber [J. H.] 1992:344, Pl. 3 (d); Fig. 66 [Review of Rivulus: Ecobiogeography -- Relationships; ref. 20639] Río Putumayo basin, El Estrecho, Fundo Alvarez, Quebradita, northern Peru. Holotype: NRM 16550. Paratypes: MNHN 1991-6861 (6); NRM 14657 (3), 15269 (63, now 56). •Valid as Rivulus ophiomimus Huber 1992 -- (Huber 1999:49 [ref. 23834], Lazara 2001:282 [ref. 25711], Costa in Reis et al. 2003:538 [ref. 27061], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys, Costa & De Luca 2011:356 [ref. 31193]). •Valid as Anablepsoides ophiomimus (Huber 1992) -- (Costa 2011:243 [ref. 31655], DoNascimiento et al. 2017:101 [ref. 35633], Meza-Vargas et al. 2021:27 [ref. 39298]). Current status: Valid as Anablepsoides ophiomimus (Huber 1992). Rivulidae: Rivulinae. Distribution: South America: Amazon River basin (Colombia and Peru). Habitat: freshwater.

origuelai, Anablepsoides Nielsen [D. T. B.] & Veiga [R. P.] 2021:6, Figs. 1-2, 4 [aqua, International Journal of Ichthyology v. 27 (no. 1); ref. 38269] Igarapé do Juá, Rio Tapajós drainage, Santarém, Pará State, Brazil, 2°26'41"S, 54°47'20"W. Holotype: ZUEC 17329. Paratypes: ZUEC 17330 (20). •Valid as Anablepsoides origuelai Nielsen & Veiga 2021 -- (Nielsen & Veiga 2023:293 [ref. 40334]). Current status: Valid as Anablepsoides origuelai Nielsen & Veiga 2021. Rivulidae: Rivulinae. Distribution: South America: lower Rio Tapajós drainage (Pará State, Brazil). Habitat: freshwater.

ornatipinnis, Neofundulus Myers [G. S.] 1935:8 [Proceedings of the Biological Society of Washington v. 48; ref. 3109] Swamp at Makthlawaiya, 60 miles west of Río Paraguay, Paraguay, 23°25'S, 58°19'W. Holotype: USNM 94401. •Valid as Neofundulus ornatipinnis Myers 1935 -- (Parenti 1981:489 [ref. 7066], Costa 1993:618 [ref. 21314], Huber 1995:20 [ref. 22880], Costa 1998:78 [ref. 23792], Lazara 2001:215 [ref. 25711], Costa in Reis et al. 2003:532 [ref. 27061], López et al. 2003:70 [ref. 27366] as ornatipinniss, Menni 2004:86 [ref. 28131], Calviño 2005:17 [ref. 28325], Nielsen & Brousseau 2013:114 [ref. 32795], Sarmiento et al. 2014:187 [ref. 35004]). •Synonym of Neofundulus paraguayensis (Eigenmann & Kennedy 1903) -- (Mirande & Koerber 2015:51 [ref. 35117] with question, Koerber et al. 2017:7 [ref. 35083], Koerber et al. 2017:71 [ref. 35267], Koerber et al. 2017:8 [ref. 35632], Mirande & Koerber 2020:2 [ref. 37594]). Current status: Synonym of Neofundulus paraguayensis (Eigenmann & Kennedy 1903). Rivulidae: Rivulinae. Habitat: freshwater.

ornatus, Rivulus Garman [S.] 1895:139 [Memoirs of the Museum of Comparative Zoology v. 19 (pt 1); ref. 1538] Lago Aleixo, Codajás, Silves, Amazonas, Brazil. Lectotype: MCZ 6266. Paralectotypes: MCZ 6336 (1), 6854 (4). Lectotype selected in Huber 1992:347 [ref. 20639]. Type locality from Costa & Lazzarotto 2008:129 [ref. 29870]. •Synonym of Rivulus obscurus Garman 1895 -- (Hrbek et al. 2004:569 [ref. 27910]). •Valid as Rivulus ornatus Garman 1895 -- (Ortega & Vari 1986:19 [ref. 9708], Huber 1992:347 [ref. 20639], Lazara 2001:282 [ref. 25711], Costa in Reis et al. 2003:538 [ref. 27061], Costa 2003:176 [ref. 27578], Costa 2004:4 [ref. 27570], Costa 2004:11 [ref. 27656], Costa 2004:2 [ref. 27923], Costa 2006:147 [ref. 28875] in subgenus Anablepsoides, Costa & Lazzarotto 2008:129 [ref. 29870], Schindler & Valdesalici 2011:113 [ref. 31382], Huber 2021:9 [ref. 38709]). •Valid as Anablepsoides ornatus (Garman 1895) -- (Costa 2011:243 [ref. 31655], DoNascimiento et al. 2017:101 [ref. 35633], Nielsen & Veiga 2021:10 [ref. 38269], Meza-Vargas et al. 2021:27 [ref. 39298]). Current status: Valid as Anablepsoides ornatus (Garman 1895). Rivulidae: Rivulinae. Distribution: South America: Amazon River basin (Brazil and Peru). Habitat: freshwater.

ortegai, Moema Costa [W. J. E. M.] 2003:7, Figs. 3B, 4 [Boletim do Museu Nacional do Rio de Janeiro, Zoologia, Nova Série No. 513; ref. 27634] Reserva Natural Tambopata, Cocha Redonda, 1.5 kilometers from Katicocha, rio Madre de Dios drainage, Amazonian basin, about 12°20'S, 69°20'W, Depto Madre de Dios, Peru. Holotype: MUSM 20177. Paratypes: MUSM 3069 (4); UFRJ 5445 (1), 5446 (1 c&s). Moema quiii Huber 2003 published earlier [12 Nov., ortegai published on 24 Nov.] (K. Lazara, pers. comm. 3/5/2011). •Valid as Moema ortegai Costa 2003 -- (Valdesalici et al. 2015:128 [ref. 33902], Valdesalici 2016:66 [ref. 34174]). •Synonym of Moema quiii Huber 2003 -- (K. Lazara, pers. comm. 3/5/2011, no decision in Valdesalici et al. 2015:132 [ref. 33902]). Current status: Synonym of Moema quiii Huber 2003. Rivulidae: Rivulinae. Habitat: freshwater.

oscari, Renova Thomerson [J. E.] & Taphorn [D. C.] 1995:187, Fig. 1 [Ichthyological Exploration of Freshwaters v. 6 (no. 2); ref. 21879] Southwestern edge of Isla Raton near the village of Sabanita, upper Río Orinoco, 5°05'N, 67°48'W, Amazonas, Venezuela. Holotype: MCNG 27070. Paratypes: CAS 81654 (4); FMNH 104897 (4); MAC-PAY 2462 (1); MCNG 26441 (16, 4 c&s), 27068 (13); MZUSP uncat. (6). •Valid as Renova oscari Thomerson & Taphorn 1995 -- (Costa 1998:79 [ref. 23792], Lazara 2001:267 [ref. 25711], Costa in Reis et al. 2003:534 [ref. 27061]). Current status: Valid as Renova oscari Thomerson & Taphorn 1995. Rivulidae: Rivulinae. Distribution: Orinoco River basin, Venezuela. Habitat: freshwater.

oticus, Cynolebias Costa [W. J. E. M.] 2014:91, Fig. 6 [Ichthyological Exploration of Freshwaters v. 25 (no. 1); ref. 33510] Temporary pool close to road BR-122, about 8 km south of village of Pindaí, Mata Veado creek floodplains, Verde River drainage, 14°33'39"S, 42°42'10"E, São Francisco River Basin, Brazil, elevation 628 meters. Holotype: UFRJ 9437. Paratypes: BMNH 2013.6.23.5-6 (2), SMF, UFRJ, ZFMK. Plus non-type material. •Valid as Cynolebias oticus Costa 2014 -- (Costa 2017:340 [ref. 35623], Silva et al. 2020:14 [ref. 37809]). Current status: Valid as Cynolebias oticus Costa 2014. Rivulidae: Cynolebiinae. Distribution: Mata Veado creek floodplains, Verde River drainage, São Francisco River Basin, Brazil. Habitat: freshwater.

ottonii, Anablepsoides Costa [W. J. E. M.], Bragança [P. H. N.] & Amorim [P. F.] 2013:289, Figs. 4b,5 [Vertebrate Zoology v. 63 (no. 3); ref. 33108] Estado do Amazonas, Município de Barcelos, Igarapé do Cajarazinho, a stream near the village of Balaio, a tributary of the Caurés river, Negro river drainage, Amazonas river basin, 1°06′ 17″S ,62°58’42″ W, Brazil. Holotype: UFRJ 9612. Paratypes: UFRJ 9613 (31), 9614 (4), 9615 (4). •Valid as Anablepsoides ottonii Costa, Bragança & Amorim 2013 -- (Nielsen & Veiga 2021:10 [ref. 38269]). Current status: Valid as Anablepsoides ottonii Costa, Bragança & Amorim 2013. Rivulidae: Rivulinae. Distribution: South America: Caurés River drainage, Negro River basin, Brazil. Habitat: freshwater.

pacificus, Rivulus Huber [J. H.] 1992:351, Fig. 67 [Review of Rivulus: Ecobiogeography -- Relationships; ref. 20639] Condoto, in forest along Condoto to Soledad road, Río San Juan basin, Colombia. Holotype: ICN-MHN 4151 [ex NRM 16551]. Paratypes: BMNH 1910.7.11.211-216 (25), 1913.10.1.69-78 (6); CAS 76354 [ex IU 13602] (14), 76356 [ex IU 13601] (8); NRM 14683 (2). Type catalog: Mojica & Agudelo-Zamora 2018:50 [ref. 36127]. •Valid as Rivulus pacificus Huber 1992 -- (Lazara 2001:282 [ref. 25711], Costa in Reis et al. 2003:538 [ref. 27061], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys, Huber et al. 2023:78 [ref. 40176]). •Valid as Cynodonichthys pacificus (Huber 1992) -- (Costa 2011:242 [ref. 31655], DoNascimiento et al. 2017:101 [ref. 35633]). Current status: Valid as Cynodonichthys pacificus (Huber 1992). Rivulidae: Rivulinae. Distribution: South America: upper and middle San Juan and Atrato River basins, Colombia. Habitat: freshwater.

pantanalensis, Cynolebias Seegers [L.] 1988:31, Figs. 1-2, 4 [Die Aquarien- und Terrarienzeitschrift (DATZ) v. 41 (no. 4); ref. 9098] Transpantaneira road, between Poconé and Corumbá, 16°43'S, 56°50'W, Sararé River, tributary of Paraguay River, Mato Grosso, Brazil. Holotype: ZFMK 15534. Paratypes: MZSUP (4); ZFMK 15535-42 (8). Type catalog: Herder et al. 2010:124 [ref. 31087]. •Synonym of Plesiolebias glaucopterus (Costa & Lacerda 1988) -- (Costa 1991:375 [ref. 13611], Costa 1995:28 [ref. 22097], Costa 1998:319 [ref. 23324], Lazara 2001:257 [ref. 25711], Costa in Reis et al. 2003:533 [ref. 27061]). Current status: Synonym of Plesiolebias glaucopterus (Costa & Lacerda 1988). Rivulidae: Rivulinae. Habitat: freshwater.

papilliferus, Nematolebias Costa [W. J. E. M.] 2002:47, Figs. 5-6 [Ichthyological Exploration of Freshwaters v. 13 (no. 1); ref. 26064] Temporary pool close to a small stream of laguna de Maricá system, road RJ-106, 22°55'14.5"S, 42°55'41.4"W, Inoã, Estado do Rio de Janeiro, Brazil. Holotype: MZUSP 52964. Paratypes: BMNH 2013.6.23.11-12 (2); MZUSP 52965 (1), 52966 (4); UFRJ 2200 (2), 4652 (2, c&s), 4710 (19, 2 c&s), 4711 (3), 5295 (16), 5296 (4), 5360 (12), 5361 (12), 5364 (71), 5365 (10, 5 c&s); UMMZ 234763 (15). •Valid as Nematolebias papilliferus Costa 2002 -- (Costa in Reis et al. 2003:532 [ref. 27061], Costa 2006:15 [ref. 28620], Costa et al. 2014:226 [ref. 33239]). Current status: Valid as Nematolebias papilliferus Costa 2002. Rivulidae: Cynolebiinae. Distribution: Laguna de Maricá and Laguna de Saquarema basins, Rio de Janeiro State, Brazil. Habitat: freshwater.

paracatuensis, Rivulus Costa [W. J. E. M.] 2003:41, Fig. 2 [aqua, Journal of Ichthyology and Aquatic Biology v. 7 (no. 1); ref. 26966] Stream in Rio Paracatú floodplains near Brasilândia de Minas, road MG 181, Rio São Francisco basin,, about 17°00'00"S, 46°00'00"W, Estado de Minas Gerais, Brazil. Holotype: MCP 29639. Paratypes: MCP 29640 (1), UFRJ 2290 (3), 2291 (2, 1 c&s). •Valid as Rivulus paracatuensis Costa 2003 -- (Costa 2006:162 [ref. 28875] in subgenus Melanorivulus). •Valid as Melanorivulus paracatuensis (Costa 2003) -- (Costa 2011:241 [ref. 31655], Costa 2012:61 [ref. 32069]). Current status: Valid as Melanorivulus paracatuensis (Costa 2003). Rivulidae: Rivulinae. Distribution: São Francisco River basin, Brazil. Habitat: freshwater.

paradiseus, Rivulus Huber [J. H.], Mejía-Vargas [D. A.] & Vermeulen [F. B. M.] 2023:88, Figs. 10-11 [Killi-Data Series 2023; ref. 40176] About 3.7 km airline west of Acandí seacoast, a bit north ot the prolongation of Calle 8, Chocó, Caribbean coast, northwestern Colombia, 8.507N, 77.309W. Holotype: CIUA 7706. Paratypes: BMNH 2022.8.19.1-4 (4), CIUA 7707 (17), MNHN 2022-0257 (5). Genus tentative. •Valid as Cynodonichthys paradiseus (Huber, Mejía-Vargas & Vermeulen, 2023). Current status: Valid as Cynodonichthys paradiseus (Huber, Mejía-Vargas & Vermeulen, 2023). Rivulidae: Rivulinae. Distribution: South America: lower Acandí River basin, Chocó, Caribbean coast, northwestern Colombia. Habitat: freshwater.

paraguassuensis, Cynolebias Costa [W. J. E. M.], Suzart [R. dos R.] & Nielsen [D. T. B.] 2007:130, Figs. 1-2 [aqua, International Journal of Ichthyology v. 12 (no. 3); ref. 29226] Município de Itaberaba, temporary pool close to road BA-488, near riacho Novo, a tributary of rio Paraguaçu, about 12°20'S, 40°00'W, Bahia State, Brazil. Holotype: UFRJ 6454. Paratypes: UFRJ 6455 (5), 6456 (1), 6457 (3, c&s). •Valid as Cynolebias paraguassuensis Costa, Suzart & Nielsen 2007 -- (Costa 2014:80 [ref. 33510], Silva et al. 2020:14 [ref. 37809], Vieira-Guimarães et al. 2024:54 [ref. 41258]). Current status: Valid as Cynolebias paraguassuensis Costa, Suzart & Nielsen 2007. Rivulidae: Cynolebiinae. Distribution: South America: Paraguaçu River drainage, Bahia State (Brazil). Habitat: freshwater.

paraguayensis, Fundulus Eigenmann [C. H.] & Kennedy [C. H.] 1903:530 [Proceedings of the Academy of Natural Sciences of Philadelphia v. 55; ref. 1260] Laguna near Arroyo Trementina, a tributary of Rio Aquido Canigi; Paraguay. Holotype (unique): CAS 42533 [ex IU 10064]. •Valid as Neofundulus paraguayensis (Eigenmann & Kennedy 1903) -- (Parenti 1981:489 [ref. 7066], Costa 1993:617 [ref. 21314], Costa 1998:78 [ref. 23792], Britski et al. 1999:140 [ref. 24147], Lazara 2001:215 [ref. 25711], Costa in Reis et al. 2003:532 [ref. 27061], López et al. 2003:70 [ref. 27366], Menni 2004:86 [ref. 28131], Calviño 2005:15 [ref. 28325], Nielsen & Brousseau 2013:114 [ref. 32795], Sarmiento et al. 2014:187 [ref. 35004], Costa 2015:23 [ref. 33783], Mirande & Koerber 2015:51 [ref. 35117], Calviño et al. 2016:10 [ref. 34699], Koerber et al. 2017:7 [ref. 35083], Koerber et al. 2017:71 [ref. 35267], Koerber et al. 2017:8 [ref. 35632], Dickens 2019:168 [ref. 37135] as cf. paraguayensis, Koerber et al. 2019:9 [ref. 36736], Drawert 2023:35 [ref. 40730]). Current status: Valid as Neofundulus paraguayensis (Eigenmann & Kennedy 1903). Rivulidae: Rivulinae. Distribution: South America: Paraguay River basin (Argentina, Brazil, Bolivia and Paraguay). Habitat: freshwater.

parallelus, Simpsonichthys Costa [W. J. E. M.] 2000:13, Figs. 7-8 [Aquarium (Brasil) v. 3 (no. 25); ref. 25933] Alagado sazonal na várzea do rio Formoso, um tributário do rio Correntes, Estado de Goiás, Brazil. Holotype: MZUSP 57357. Paratypes: MCP 22681 (4); MZUSP 57538 (4); UFRJ 4838-39 (7, 4), 5196-97 (16, 4). •Valid as Simpsonichthys parallelus Costa 2000 -- (Costa et al. 2003:140 [ref. 26946], Costa in Reis et al. 2003:542 [ref. 27061], Costa 2006:17 [ref. 28620], Costa & Brasil 2006:221 [ref. 28843], Costa 2007:200 [ref. 29338], Costa 2007:29 [ref. 29445], Costa 2012:314 [ref. 31750], Nielsen et al. 2017:166 [ref. 35304]). Current status: Valid as Simpsonichthys parallelus Costa 2000. Rivulidae: Cynolebiinae. Distribution: Formoso River, Goiás, rio Paranaíba drainage, central Brazil. Habitat: freshwater.

paranaensis, Austrolebias Costa [W. J. E. M.] 2006:69, Fig. 28 [Zootaxa No. 1213; ref. 28708] Temporary pools adjacent to río Paraná, about 2 kilometers east of Ayolas, 27°24'00"'S, 56°46'12"W, Misiones, Paraguay. Holotype: UFRJ 6239. Paratypes: UFRJ 4974 (3, c&s), 4975 (11). •Valid as Austrolebias paranaensis Costa 2006 -- (Volcan et al. 2017:387 [ref. 35260], Koerber et al. 2017:70 [ref. 35267]). •Valid as Argolebias paranaensis (Costa 2006) -- (Alonso et al. 2023:7 [ref. 40292], Alonso et al. 2024:311 [ref. 40863], Koerber 2024:6 [ref. 41228]). Current status: Valid as Argolebias paranaensis (Costa 2006). Rivulidae: Cynolebiinae. Distribution: South America: Paraná River floodplains (southern Paraguay). Habitat: freshwater.

paranaguensis, Atlantirivulus Costa [W. J. E. M.] 2014:15, Figs. 6-7 [Vertebrate Zoology v. 64 (no. 1); ref. 33307] Estado do Paraná, Município de Paranaguá, stream crossing the road PR --407, about 2 km from Vila dos Comerciários, town of Paranaguá, 25°36′ 03″ S, 48°33′ 28″ W, Brazil. Holotype: UFRJ 9794. Paratypes: UFRJ 5217 (7), 6362 (17), 6363 (4), 9763 (4). Plus non-type specimens. •Possibly a synonym of Rivulus rachovii Ahl 1925 -- (Huber 2017:20 [ref. 35720]). •Valid as Atlantirivulus paranaguensis Costa 2014 -- (Reis et al. 2020:473 [ref. 38364], Volcan et al. 2024:98 [ref. 41345]). Current status: Valid as Atlantirivulus paranaguensis Costa 2014. Rivulidae: Rivulinae. Distribution: South America: small river basins flowing into Paranaguá Bay, southeastern Mata Atlantica (Brazil). Habitat: freshwater.

paranaguensis, Cynolebias Myers [G. S.] 1952:131 [Aquarium Journal v. 23 (no. 7); ref. 3125] Name mentioned without correlation to text. See Cynolebias aureoguttatus Myers 1952. •In the synonymy of Leptolebias aureoguttatus (Da Cruz 1974) -- (Lazara 2001:193 [ref. 25711], Costa in Reis et al. 2003:530 [ref. 27061], Costa 2008:149 [ref. 29596]). •In the synonymy of Leptopanchax aureoguttatus (Da Cruz 1974). Nomen Nudum. Current status: Synonym of Leptopanchax aureoguttatus (Da Cruz 1974). Rivulidae: Cynolebiinae.

paresi, Rivulus Costa [W. J. E. M.] 2008:354, Figs. 3-4 [Ichthyological Exploration of Freshwaters v. 18 (no. 4) [for 2007]; ref. 29384] Swampy floodplains of stream tributary to Sepotuba River, upper Paraguay River basin, near road MT-338, 2 kilometers of Progresso, Tangará de Serra, 14°38'40"S, 57°20'41"W, Est. de Mato Grosso, Brazil, elevation 500 meters. Holotype: UFRJ 6505. Paratypes: UFRJ 6506 (11), 6507 (4, c&s), 6508 (3). •Valid as Melanorivulus paresi (Costa 2008) -- (Costa 2011:241 [ref. 31655] with date as 2007, Deprá et al. 2017:121 [ref. 35503]). Current status: Valid as Melanorivulus paresi (Costa 2008). Rivulidae: Rivulinae. Distribution: Rio Sepotuba, Upper Paraguay River basin, Brazil. Habitat: freshwater.

parietalis, Cynolebias Costa [W. J. E. M.] 2014:89, Fig. 5 [Ichthyological Exploration of Freshwaters v. 25 (no. 1); ref. 33510] Temporary pool about 1 km east of the village of Gado Bravo, Verde Gande river floodplains, São Francisco River Basin,14°55'16"S, 43°29'31"W, Brazil, elevation 450 meters. Holotype: UFRJ 9449. Paratypes: BMNH 2013.6.23.5-6 (2), UFRJ, ZFMK. Plus additional non-type material. •Valid as Cynolebias parietalis Costa 2014. Current status: Valid as Cynolebias parietalis Costa 2014. Rivulidae: Cynolebiinae. Distribution: Temporary pool near Gordo Bravo, São Francisco River Basin, Brazil. Habitat: freshwater.

parlettei, Rivulus Valdesalici [S.] & Schindler [I.] 2011:314, Figs. 1-2 [Vertebrate Zoology v. 61 (no. 3); ref. 31673] Río Inambari system, río Araza drainage, 13.313°S, 70.803°W, Departamento Cusco, Peru, elevation ca. 820 meters. Holotype: MUSM 39906. Paratypes: MSNG 56048A (1), 56048B (1), 56048C (1); MTD 32437 (1); USNM 399459 (1). •Valid as Anablepsoides parlettei (Valdesalici & Schindler 2011) -- (based on recognition of Anablepsoides as a valid genus by Costa 2011:242 [ref. 31655], Costa 2013:346 [ref. 32528], Valdesalici & Schindler 2013:296 [ref. 33109], Nielsen et al. 2016:76 [ref. 34406], Nielsen 2016:166 [ref. 34861], Valdesalici & Gil 2019:152 [ref. 37074]). Current status: Valid as Anablepsoides parlettei (Valdesalici & Schindler 2011). Rivulidae: Rivulinae. Distribution: Río Araza drainage, upper Amazon basin, southeastern Peru. Habitat: freshwater.

parnaibensis, Cynolebias Costa [W. J. E. M.], Ramos [T. P. A.], Alexandre [L. C.] & Ramos [R. T. C.] 2010:284, Fig. 1 [Neotropical Ichthyology v. 8 (no. 2); ref. 30866] Seasonal lagoon at the right side of the road between Conceição do Canindé and Jacobina do Piauí, 8°00'54"S, 41°25'26"W, Município de Jacobina do Piauí, Estado do Piauí, Brazil. Holotype: UFPB 6719. Paratypes: UFPB 6709 (6), 6734 (2), 6735 (3, 2 c&s), 6736 (2). •Valid as Cynolebias parnaibensis Costa, Ramos, Alexandre & Ramos 2010 -- (Costa 2014:80 [ref. 33510], Ramos et al. 2014:4 [ref. 35321]). Current status: Valid as Cynolebias parnaibensis Costa, Ramos, Alexandre & Ramos 2010. Rivulidae: Cynolebiinae. Distribution: Northeastern Brazil. Habitat: freshwater.

parnaibensis, Rivulus Costa [W. J. E. M.] 2003:2, Figs. 1-2 [Boletim do Museu Nacional do Rio de Janeiro, Zoologia, Nova Série No. 511; ref. 27635] Lagoon close to the road BR-135, 18 kilometers northeast of São Dimas, about 9°40'S, 45°00'W, Parnaiba River basin, Piauí, northeastern Brazil. Holotype: MCP 29639. Paratypes: MCP 29640 (5); UFRJ 4962 (25), 5449 (4, 2 c&s). •Valid as Rivulus parnaibensis Costa 2003 -- (Costa 2006:162 [ref. 28875] in subgenus Melanorivulus). •Valid as Melanorivulus parnaibensis (Costa 2003) -- (Costa 2011:241 [ref. 31655], Nelsen & Costa 2011:241 [ref. 31655], Ramos et al. 2014:4 [ref. 35321], Nelsen & Pinto 2015:136 [ref. 33903], Costa 2016:139 [ref. 34900], Nielsen 2017:66 [ref. 35340], Nielsen & Britzke 2019:42 [ref. 36525], Koerber et al. 2022:75 [ref. 39235]). Current status: Valid as Melanorivulus parnaibensis (Costa 2003). Rivulidae: Rivulinae. Distribution: South America: Parnaíba River basin (northeastern Brazil). Habitat: freshwater.

parvipinnis, Neofundulus Costa [W. J. E. M.] 1988:109, Figs. 4-5 [Revista Brasileira de Biologia v. 48 (no. 2); ref. 14292] Lagoa na margem direita da Br 364, 36 kilometers leste de Cuiabá, Mato Grosso, Brazil. Holotype: MZUSP 36618. Paratypes: MZUSP 36619 (1), 26620 [?36620] (5), 36687 (1). •Valid as Neofundulus parvipinnis Costa 1988 -- (Costa 1993:618 [ref. 21314], Costa 1998:78 [ref. 23792], Britski et al. 1999:140 [ref. 24147], Lazara 2001:215 [ref. 25711], Costa in Reis et al. 2003:532 [ref. 27061], Calviño 2005:15 [ref. 28325], Nielsen & Brousseau 2013:114 [ref. 32795], Costa 2015:16 [ref. 33783]). Current status: Valid as Neofundulus parvipinnis Costa 1988. Rivulidae: Rivulinae. Distribution: Paraguay River basin, Brazil. Habitat: freshwater.

paryagi, Laimosemion Vermeulen [F. B. M.], Suijker [W. H.] & Collier [G. E.] 2012:183, Figs. 1-2 [aqua, International Journal of Ichthyology v. 18 (no. 4); ref. 32253] Upper Mazaruni River, about 7 miles downstream from Kamarang, 5°43'50"N, 60°30'55"W, Upper Mazaruni District, Guyana, elevation about 495 meters. Holotype: ZMA 124896. Paratypes: ZAM 124897 (1) and 6 F1 generation males. •Valid as Laimosemion paryagi Vermeulen, Suijker & Collier 2012 -- (Taphorn et al. 2022:37 [ref. 41297]). Current status: Valid as Laimosemion paryagi Vermeulen, Suijker & Collier 2012. Rivulidae: Rivulinae. Distribution: South America: upper Mazaruni River (Guyana) endemic. Habitat: freshwater.

pataxo, Xenurolebias Costa [W. J. E. M.] in Costa & Amorim 2014:358, Figs. 3-4, 8 [Systematics and Biodiversity v. 12 (issue 3); ref. 33343] Seasonal pool within forest, about 5 km W of the town of Mucuri, Mucuri municipality, Bahia State, Brazil, 18°03'48"S, 39°33'53"W. Holotype: UFRJ 9732. Paratypes: UFRJ. Plus additional non-type material. •Valid as Xenurolebias pataxo Costa 2014 -- (Vieira-Guimarães et al. 2024:55 [ref. 41258]). Current status: Valid as Xenurolebias pataxo Costa 2014. Rivulidae: Cynolebiinae. Distribution: South America: Mucuri, Itanhem and Jucuruçu river basins, southern Bahia State (Brazil). Habitat: freshwater.

patriciae, Cynolebias Huber [J. H.] 1995:6, Fig. 2 [Killi-Contact - Périodique bimestriel Spec. publ.; ref. 22880] Ditch along the road to Clorinda, Presidente Hayes Province, about 500 meters south of Río Negro, 25.25°S, 57.67°W, Paraguay. Holotype: ANSP 170424. Paratypes: ANSP 170424B (5), MACN (2), MNHN 1993-3620 (5), MNHNP (4). Apparently appeared first as above in ref. 22880, then in Huber 1995:114, Figs. 2-4 [ref. 22204]. •Valid as Austrolebias patriciae (Huber 1995) -- (Costa 1998:76 [ref. 23792], Lazara 2001:63 [ref. 25711], Costa 2002:917 [ref. 26505], Costa in Reis et al. 2003:528 [ref. 27061], Calviño 2005:16 [ref. 28325] as cf. patriciae, Calviño 2006:183 [ref. 28679] as cf. patriciae, Costa 2006:95 [ref. 28708], Mirande & Koerber 2015:51 [ref. 35117], Calviño et al. 2016:10 [ref. 34699], Koerber et al. 2017:71 [ref. 35267], Alonso et al. 2018:5 [ref. 35938]). •Valid as Amatolebias patriciae (Huber 1995) -- (Alonso et al. 2023:9 [ref. 40292], Koerber et al. 2023:4 [ref. 40368], Koerber 2024:6 [ref. 41228]). Current status: Valid as Amatolebias patriciae (Huber 1995). Rivulidae: Cynolebiinae. Distribution: South America: Paraguay River basin (Paraguay and Argentina). Habitat: freshwater.

paucisquama, Austrolebias Ferrer [J.], Malabarba [L. R.] & Costa [W. J. E. M.] 2008:176, Figs. 1-3 [Neotropical Ichthyology v. 6 (no. 2); ref. 29705] São Sepé, temporary pool close to BR-290 highway (30°22'27"S, 53°33'42"W), rio Vacacaí drainage, rio Jacuí tributary, Rio Grande do Sul, Brazil. Holotype: MCP 41879. Paratypes: MCP 41880 (26, 3 c&s); UFRGS 9354 (3, c&s), 9355 (7); UFRJ 6522 (10, 2 c&s). •Valid as Austrolebias paucisquama Ferrer, Malabarba & Costa 2008 -- (Bertaco et al. 2016:424 [ref. 34561], Volcan et al. 2017:151 [ref. 35644], Loureiro et al. 2018:11 [ref. 36240]). •Valid as Matilebias paucisquama (Ferrer, Malabarba & Costa 2008) -- (Alonso et al. 2023:9 [ref. 40292]). Current status: Valid as Matilebias paucisquama (Ferrer, Malabarba & Costa 2008). Rivulidae: Cynolebiinae. Distribution: South America: Rio Vacacaí drainage, Laguna dos Patos drainage, southern Brazil. Habitat: freshwater.

pelotapes, Austrolebias Costa [W. J. E. M.] & Cheffe [M. M.] in Costa, Cheffe & Amorim 2017:141, Figs. 2-3 [Vertebrate Zoology v. 67 (no. 2); ref. 35626] Temporary pool in the Sanga Funda drainage, tributary of Arroio Pelotas, Município de Pelotas, Rio Grande do Sul, Brazil, 31°43'46"S, 52°19'07"W. Holotype: UFRJ 8601. Paratypes: CIMC, UFRJ. •Valid as Austrolebias pelotapes Costa & Cheffe 2017 -- (Volcan et al. 2021:104 [ref. 38292]). •Valid as Garcialebias pelotapes (Costa & Cheffe 2017) -- (Alonso et al. 2023:13 [ref. 40292]). Current status: Valid as Garcialebias pelotapes (Costa & Cheffe 2017). Rivulidae: Cynolebiinae. Distribution: South America: drainages to the northern margin of the Canal de São Gonçalo, Laguna dos Patos system, Rio Grande do Sul, Brazil. Habitat: freshwater.

pepotei, Moema Costa [W. J. E. M.] 1993:621, Fig. 6 [Revista Brasileira de Biologia v. 52 (no. 4) (for Nov. 1992); ref. 21979] Forte Príncipe di Beira, Rio Guaporé River basin, Rondônia State, Brazil. Holotype (unique): CAS-SU 63604. •Valid as Moema pepotei Costa 1993 -- (Chang & Ortega 1995:4 [ref. 24302], Costa 1998:79 [ref. 23792], Lazara 2001:211 [ref. 25711], Costa in Reis et al. 2003:532 [ref. 27061], Huber 2003:14 [ref. 27251], Costa 2003:173 [ref. 27617], Costa 2003:2 [ref. 27634], Sarmiento et al. 2014:187 [ref. 35004], Valdesalici et al. 2015:128 [ref. 33902], Valdesalici 2016:66 [ref. 34174], Valdesalici 2019:109 [ref. 36959], Drawert 2022:13 [ref. 39805], Drawert 2023:34 [ref. 40730]). Current status: Valid as Moema pepotei Costa 1993. Rivulidae: Rivulinae. Distribution: South America: Guaporé and Mamoré River drainages (Bolivia and Brazil). Habitat: freshwater.

perforatus, Cynolebias Costa [W. J. E. M.] & Brasil [G. C.] 1991:56, Figs. 1, 2b [Ichthyological Exploration of Freshwaters v. 2 (no. 1); ref. 16651] Near the City of Januária, County of Januária, Minas Gerais State, Brazil. Holotype: MZUSP 41376. Paratypes: MZUSP 42377 (3) •Valid as Cynolebias perforatus Costa & Brasil 1991 -- (Costa 1995:82 [ref. 22097], Costa 1998:238 [ref. 23578], Costa 1998:76 [ref. 23792], Lazara 2001:77 [ref. 25711], Costa 2001:367 [ref. 25719], Costa in Reis et al. 2003:529 [ref. 27061], Costa 2009:147 [ref. 30511], Costa 2014:79 [ref. 33510]). Current status: Valid as Cynolebias perforatus Costa & Brasil 1991. Rivulidae: Cynolebiinae. Distribution: Middle São Francisco River basin, Brazil. Habitat: freshwater.

periodicus, Cynolebias Costa [W. J. E. M.] 1999:299, Figs. 1-2 [Ichthyological Exploration of Freshwaters v. 10 (no. 4); ref. 24229] Temporary flood-plains of the rio Santa Maria, rio Ibicuí drainage, rio Uruguai basin, road BR-293, 4 kilometers west from Dom Pedrito, Estado do Rio Grande do Sul, Brazil. Holotype: MCP 20819. Paratypes: MCP 20820 (5); MZUSP uncat. (4); UMMZ 234761 (4); UFRJ 4671 (12), 4672 (6, c&s). •Valid as Austrolebias periodicus (Costa 1999) -- (Lazara 2001:63 [ref. 25711], Costa 2002:917 [ref. 26505], Costa in Reis et al. 2003:528 [ref. 27061], Costa 2006:83 [ref. 28708], Litz & Koerber 2014:30 [ref. 33622], Bertaco et al. 2016:424 [ref. 34561], Nión et al. 2016:43 [ref. 35565], Volcan et al. 2017:151 [ref. 35644], Loureiro et al. 2018:11 [ref. 36240], Loureiro et al. 2023:166 [ref. 40506]). •Valid as Matilebias periodicus (Costa 1999) -- (Alonso et al. 2023:9 [ref. 40292], Koerber et al. 2023:11 [ref. 40355]). Current status: Valid as Matilebias periodicus (Costa 1999). Rivulidae: Cynolebiinae. Distribution: South America: Uruguay River basin (Argentina, Brazil and Uruguay). Habitat: freshwater.

perpendicularis, Simpsonichthys Costa [W. J. E. M.], Nielsen [D. T. B.] & de Luca [A. C.] 2001:26, Fig. [Aquarium (Brasil) v. 4 (no. 26); ref. 25934] Poça temporária perto do ribeirão do Salto, Estrada entre Itarantim e Jordânia, about 6 kilometers de Jordânia, bacia deo rio Jequitinhonha, Bahia, Brazil. Holotype: MZUSP 62570. Paratypes: MZUSP 62571 (5); UFRJ 5144-45 (10, 5). •Valid as Simpsonichthys perpendicularis Costa, Nielsen & de Luca 2001 -- (Costa in Reis et al. 2003:542 [ref. 27061], Costa 2004:6 [ref. 27569], Costa 2007:21 [ref. 29445], Costa & Lima 2010:205 [ref. 31041] in subgenus Ophthalmolebias). •Valid as Ophthalmolebias perpendicularis (Costa, Nielsen & de Luca 2001) -- (Silva et al. 2020:15 [ref. 37809], Vieira-Guimarães et al. 2024:55 [ref. 41258]). Current status: Valid as Ophthalmolebias perpendicularis (Costa, Nielsen & de Luca 2001). Rivulidae: Cynolebiinae. Distribution: South America: Jequitinhonha River basin, Bahia State (Brazil). Habitat: freshwater.

peruanus, Haplochilus Regan [C. T.] 1903:626 [Annals and Magazine of Natural History (Series 7) v. 12 (no. 72) (art. 64); ref. 13401] Perim, Peru, elevation 800 meters. Lectotype: BMNH 1903.11.5.2. Paralectotypes: BMNH 1903.11.5.3 (1). Type catalog: Huber 1992 [ref. 20639]. Lectotype selected in Huber 1992:355 [ref. 20639]. •Valid as Rivulus peruanus (Regan 1903) -- (Ortega & Vari 1986:19 [ref. 9708], Huber 1992:355 [ref. 20639], Lazara 2001:282 [ref. 25711], Costa in Reis et al. 2003:538 [ref. 27061], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys). •Valid as Anablepsoides peruanus (Regan 1903)-- (Costa 2011:243 [ref. 31655]). Current status: Valid as Anablepsoides peruanus (Regan 1903). Rivulidae: Rivulinae. Distribution: Amazon River basin, Peru. Habitat: freshwater.

peruensis, Pterolebias Myers [G. S.] 1954:176, fig'd [Aquarium Journal v. 25; ref. 12659] About 75 miles west of Leticia, Loreto Province, Peru. Holotype: CAS-SU 47658. Paratypes: CAS-SU 47659 (3). Name was spelled peruvianus in Knaack 1970:58 [ref. 25875]. •Valid as Pterolebias peruensis Myers 1954 -- (Ortega & Vari 1986:19 [ref. 9708]). •Valid as Aphyolebias peruensis (Myers 1954) -- (Costa 1998:78 [ref. 23792], Lazara 2001:5 [ref. 25711], Costa in Reis et al. 2003:526 [ref. 27061], Costa 2003:156 [ref. 27616]). •Valid as Moema peruensis (Myers 1954) -- (Valdesalici et al. 2015:129 [ref. 33902], Valdesalici 2016:66 [ref. 34174], Meza-Vargas et al. 2021:27 [ref. 39298]). Current status: Valid as Moema peruensis (Myers 1954). Rivulidae: Rivulinae. Distribution: South America: Marañón River floodplains, Amazon River basin (Peru). Habitat: freshwater.

petrisecundi, Melanorivulus Costa [W. J. E. M.] 2016:129, Fig. 19 [Ichthyological Exploration of Freshwaters v. 27 (no. 2) for Oct.; ref. 34900] Swamp close to stream tributary of the Rio Araguaia, in small road close to Parque Estadual Serra das Andorinhas, Município de Sao Geraldo do Araguaia, Rio Tocantins drainage, Pará, Brazil, 6°19'26"S, 48°28'15"W, elevation about 150 meters. Holotype: UFRJ 6867. Paratypes: UFRJ. Plus a non-type specimen. •Valid as Melanorivulus petrisecundi Costa 2016 -- (Nielsen 2017:66 [ref. 35340], Nielsen & Britzke 2019:41 [ref. 36525]). Current status: Valid as Melanorivulus petrisecundi Costa 2016. Rivulidae: Rivulinae. Distribution: Rio Araguaia drainage, Pará, northern Brazil. Habitat: freshwater.

phasianus, Pterolebias Costa [W. J. E. M.] 1988:658, Fig. 1 [Journal of Zoology (London) v. 215 (pt 4); ref. 14438] Lagoon at Cáceres, Rio Cuiabá [correctly Paraguay River] floodplains, Mato Grosso, Brazil. Holotype: MZUSP 38109. Paratypes: MZUSP 38110 (1 c&s), 38111 (1). •Valid as Pterolebias phasianus Costa 1988 -- (Costa 1998:77 [ref. 23792], Britski et al. 1999:139 [ref. 24147], Lazara 2001:264 [ref. 25711], Costa in Reis et al. 2003:533 [ref. 27061], Schindler 2004:71 [ref. 28034], Costa 2005:18 [ref. 28393], Sarmiento et al. 2014:187 [ref. 35004], Drawert 2023:39 [ref. 40730]). Current status: Valid as Pterolebias phasianus Costa 1988. Rivulidae: Rivulinae. Distribution: South America: middle Paraguay River basin (Bolivia and Brazil). Habitat: freshwater.

picturatus, Simpsonichthys Costa [W. J. E. M.] 2000:12, Figs. 5-6 [Aquarium (Brasil) v. 3 (no. 25); ref. 25933] Poça temporária perto de Volta das Pedras, rio São Francisco basin, Bahia, Brazil [12°24'08.7"S, 43°12'17.7"W, elevation 445 meters]. Holotype: MZUSP 59228. Paratypes: MZUSP 59229 (8); UFRJ 5053 (46), 5054 (7), 5194 (15), 5194 [sic] (8). •Valid as Simpsonichthys picturatus Costa 2000 -- (Costa in Reis et al. 2003:542 [ref. 27061], Costa & Nielsen 2004:126 [ref. 27825], Costa 2006:17 [ref. 28620], Costa 2007:93 [ref. 29445], Costa 2010:77 [ref. 30777]). •Valid as Hypsolebias picturatus (Costa 2000) -- (based on generic placement in Costa 2011 [ref. 31654], Nielsen et al. 2014:28 [ref. 33143], Nielsen et al. 2014:132 [ref. 33451], Costa et al. 2018:155 [ref. 36034], Costa et al. 2018:499 [ref. 36319], Silva et al. 2020:14 [ref. 37809]). Current status: Valid as Hypsolebias picturatus (Costa 2000). Rivulidae: Cynolebiinae. Distribution: South America: middle São Francisco River basin (Bahia State, Brazil). Habitat: freshwater.

pictus, Rivulus Costa [W. J. E. M.] 1989:525, Figs. 2-2a [Revista Brasileira de Zoologia v. 6 (no. 3); ref. 14319] Fumal Creek at road crossing, Formosa, District Federal, Brazil. Holotype: MNRJ 11550. Paratypes: MNRJ 11551 (2), MZUSP 39975 (2). Plus non-type material. Type catalog: Huber 1992 [ref. 20639]. See Lazara 2001:283 [ref. 25711] for first reviser information. •Valid as Rivulus pictus Costa 1989 -- (Huber 1992:358 [ref. 20639], Costa 1995:212 [ref. 21883], Lazara 2001:282 [ref. 25711], Costa et al. 2003:144 [ref. 26946], Costa 2003:41 [ref. 26966], Costa in Reis et al. 2003:538 [ref. 27061], Costa 2003:2 [ref. 27635], Costa 2005:71 [ref. 28192], Costa 2006:162 [ref. 28875] in subgenus Melanorivulus, Costa 2008:88 [ref. 29717]). •Valid as Melanorivulus pictus (Costa 1989) -- (Costa 2011:241 [ref. 31655], Costa 2012:57 [ref. 32069], Nielsen et al. 2016:87 [ref. 34407], Volcan et al. 2017:92 [ref. 35156], Deprá et al. 2017:117 [ref. 35503], Volcan et al. 2018:275 [ref. 35895]). Current status: Valid as Melanorivulus pictus (Costa 1989). Rivulidae: Rivulinae. Distribution: Paraná River and Rio Corumbá basins, Brazil. Habitat: freshwater.

pilleti, Spectrolebias Nielsen [D. T. B.] & Brousseau [R.] 2013:117, Figs. 1-2 [aqua, International Journal of Ichthyology v. 19 (no. 3); ref. 32794] Departamento Santa Cruz, Quimone city, 45.40 km west of San José dos Chiquitos, temporary pool near the río Quimone, the río San Pablo basin, (17°42’48.1"S, 61°08’56.1"W), Bolivia, altitude 263 meters. Holotype: MNKP 11153. Paratypes: MNKP 11154 (13), ZUEC 7296 (2). •Valid as Spectrolebias pilleti Nielsen & Brousseau 2013 -- (Sarmiento et al. 2014:187 [ref. 35004], Nielsen & Pillet 2015:186 [ref. 34009], Drawert 2023:16 [ref. 40730]). Current status: Valid as Spectrolebias pilleti Nielsen & Brousseau 2013. Rivulidae: Cynolebiinae. Distribution: South America: Río San Pablo basin (Bolivia). Habitat: freshwater.

pindorama, Melanorivulus Costa [W. J. E. M.] 2012:58, Figs. 1-2 [Ichthyological Exploration of Freshwaters v. 23 (no. 1); ref. 32069] About 2 km east of Pindorama town, a small tributary to Gameleira River, a tributary to das Balsas River, itself a tributary to Sono River, Tocantins River drainage, Muniicipio de Pindorama do Tocantins, 11°08'34"S, 47°33'21"W, elevation 454 meters. Holotype: UFRJ 8271. Paratypes: UFRJ 8272 (5), 8273 (6). •Valid as Melanorivulus pindorama Costa 2012 -- (Nielsen & Pinto 2015:137 [ref. 33903], Costa et al. 2016:270 [ref. 35405]). Current status: Valid as Melanorivulus pindorama Costa 2012. Rivulidae: Rivulinae. Distribution: Tocantins River drainage, Brazil. Habitat: freshwater.

pinima, Rivulus Costa [W. J. E. M.] 1989:528, Figs. 4-4a [Revista Brasileira de Zoologia v. 6 (no. 3); ref. 14319] 37 kilometers east of Jataí, upper rio Paraná basin, 17°50'78"S, 51°24'13"W, Município de Rio Verde, Estado de Goiás, Brazil, elevation 782 meters. Holotype: MZUSP 39978. Paratypes: MZUSP 39979 (2), 39984 (2); plus non-type material. Type catalog: Huber 1992 [ref. 20639]. •Status uncertain -- (Huber 1992:361 [ref. 20639]). •Synonym of Rivulus pictus Costa 1989 -- (Costa 1995:212 [ref. 21883], Lazara 2001:283 [ref. 25711], Costa in Reis et al. 2003:538 [ref. 27061]). •Valid as Rivulus pinima Costa 1989 -- (Costa 2005:71 [ref. 28192], Costa 2006:162 [ref. 28875] in subgenus Melanorivulus, Costa 2006:55 [ref. 28876], Costa 2008:317 [ref. 29388], Costa 2008:85 [ref. 29717]). •Valid as Melanorivulus pinima (Costa 1989) -- (Costa 2011:241 [ref. 31655], Costa 2012:217 [ref. 32292], Nielsen & Pinto 2015:136 [ref. 33903], Nielsen et al. 2016:87 [ref. 34407], Volcan et al. 2017:92 [ref. 35156], Deprá et al. 2017:113 [ref. 35503]). Current status: Valid as Melanorivulus pinima (Costa 1989). Rivulidae: Rivulinae. Distribution: Claro and Bois river drainages, Paraná River basin, Brazil. Habitat: freshwater.

piriana, Moema Costa [W. J. E. M.] 1989:223, Fig. 1 [Revista Brasileira de Biologia v. 49 (no. 1); ref. 14270] Primaver, Pará, Brazil. Holotype: MZUSP 38517. Paratypes: MNRJ 11389-90 (1, 1); MZUSP 35514 (1, c&s), 35515 (1, c&s), 35516 (1). •Valid as Moema piriana Costa 1989 -- (Costa 1993:624 [ref. 21979], Costa 1998:79 [ref. 23792], Lazara 2001:211 [ref. 25711], Costa in Reis et al. 2003:532 [ref. 27061], Huber 2003:14 [ref. 27251], Costa 2003:167 [ref. 27617], Costa 2003:2 [ref. 27634], Valdesalici et al. 2015:129 [ref. 33902], Valdesalici 2016:66 [ref. 34174]). Current status: Valid as Moema piriana Costa 1989. Rivulidae: Rivulinae. Distribution: Lower Amazon River basin, Brazil. Habitat: freshwater.

pivijay, Rivulus Vermeulen [F. B. M.] 2013:50, Figs. 4-5 [Killi-Data Series 2013; ref. 33089] Swamp on 28.3 km at the right side of road Fundación-Pivijay, south of Ciénaga Grande de Santa Marta, Magdalena, Magdalena River system, Colombia, 10°28'25"N, 74°26'45"W, elevation 7 meters. Holotype: IAvH-P 11257. Paratypes: IAvH-P. Type catalog: DoNascimiento et al. 2016:428 [ref. 34787]. Genus tentative. •Valid as Rivulus pivijay Vermeulen 2013 -- (DoNascimiento et al. 2017:102 [ref. 35633]). •Valid as Cynodonichthys pivijay (Vermeulen 2013). Current status: Valid as Cynodonichthys pivijay (Vermeulen 2013). Rivulidae: Rivulinae. Distribution: South America: Magdalena River basin, Magdalena Department, northern Colombia. Habitat: freshwater.

planaltinus, Rivulus Costa [W. J. E. M.] & Brasil [G. C.] 2008:82, Figs. 1-2 [Copeia 2008 (no. 1); ref. 29541] Cocal River floodplains, road BR -010, about 4 kilometers south of São Gabriel de Goías, Maranhão River drainage, upper T ocantins River basin, 15╕16'11"S, 47°33'13"W, Município de Planaltine de Goías, Estado de Goías, Brazil, elevation 1100 meters. Holotype: UFRJ 6496. Paratypes: MCP 41324 (4); UFRJ 6497 (20), 6499 (4, 2 c&s). •Valid as Rivulus planaltinus Costa & Brasil 2008 -- (Costa 2008:88 [ref. 29717], Costa 2010:193 [ref. 31043]). •Valid as Melanorivulus planaltinus (Costa & Brasil 2008) -- (Costa 2011:241 [ref. 31655], Costa 2012:57 [ref. 32069], Nielsen & Pinto 2015:137 [ref. 33903], Nielsen et al. 2016:87 [ref. 34407], Costa et al. 2016:270 [ref. 35405], Deprá et al. 2017:120 [ref. 35503], Volcan et al. 2018:275 [ref. 35895]). Current status: Valid as Melanorivulus planaltinus (Costa & Brasil 2008). Rivulidae: Rivulinae. Distribution: Cocal River floodplains, Maranhão River drainage, upper Tocantins River basin, Brazil. Habitat: freshwater.

poeyi, Rivulus Steindachner [F.] 1876:165 [117] [Sitzungsberichte der Kaiserlichen Akademie der Wissenschaften. Mathematisch-Naturwissenschaftliche Classe v. 74 (1. Abth.); ref. 4225] [Original] Canal at Belém, Pará, Brazil; Cayenne, French Guiana. Neotype locality Belém, Brazil. Neotype: UFR 6282. Syntypes (?): (several) NMW 59608 (2). On p. 117 of separate. Neotype designated by Costa 2006:139, 165 [ref. 28875] without mention of possible syntypes at NNW. •Synonym of Rivulus urophthalmus Günther 1866 -- (Huber 1991:65 [ref. 19721], Huber 1992:364 [ref. 20639], Lazara 2001:285 [ref. 25711], Costa in Reis et al. 2003:540 [ref. 27061], Costa 2006:139 [ref. 28875]). •Synonym of Anablepsoides urophthalmus (Günther 1866). Current status: Synonym of Anablepsoides urophthalmus (Günther 1866). Rivulidae: Rivulinae. Habitat: freshwater.

polychromus, Melanorivulus Nielsen [D. T. B.], Aguiar Neves [P. A. B.], Ywamoto [E. V.] & de Aguiar Passos [M.] 2016:81, Figs. 1-2 [aqua, International Journal of Ichthyology v. 22 (no. 2); ref. 34407] São Paulo, Suzanápolis, Córrego Ranchiho, tributary of rio São José dos Dourados, rio Paraná basin, Brazil, 20°31'39.50"S, 51°03'06.64"W, altitude 337 meters. Holotype: MZUSP 119054. Paratypes: MZUSP. •Valid as Melanorivulus polychromus Nielsen, Aguiar Neves, Ywamoto & de Aguiar Passos 2016 -- (Volcan et al. 2017:92 [ref. 35156], Volcan et al. 2018:275 [ref. 35895], Ywamoto et al. 2020:128 [ref. 37763]). Current status: Valid as Melanorivulus polychromus Nielsen, Aguiar Neves, Ywamoto & de Aguiar Passos 2016. Rivulidae: Rivulinae. Distribution: Rio São José dos Dourados drainage, Rio Paraná basin, Brazil. Habitat: freshwater.

pongondo, Austrolebias Costa [W. J. E. M.] & Cheffe [M. M.] in Costa, Cheffe & Amorim 2017:144, Fig. 5 [Vertebrate Zoology v. 67 (no. 2); ref. 35626] Swamp at the road to Torotama island, Arraial, Povo Novo district, Município de Pelotas, Rio Grande do Sul, Brazil, 31°55'54"S, 52°14'42"W. Holotype: UFRJ 9583. Paratypes: CIMC, UFRJ. •Valid as Austrolebias pongondo Costa & Cheffe 2017 -- (Fernandes et al. 2020:[3] 3 [ref. 38700], Volcan et al. 2021:104 [ref. 38292]). •Valid as Garcialebias pongondo (Costa & Cheffe 2017) -- (Alonso et al. 2023:13 [ref. 40292]). Current status: Valid as Garcialebias pongondo (Costa & Cheffe 2017). Rivulidae: Cynolebiinae. Distribution: South America: temporary pools and swamps in the floodplains south of the São Gonçalo channel, Rio Grande do Sul state, southeastern Brazil. Habitat: freshwater.

poranga, Pituna Costa [W. J. E. M.] 1989:226, Fig. 3 [Revista Brasileira de Biologia v. 49 (no. 1); ref. 14270] Aruanã, Goiás, Brazil, about 15°00'S, 51°00'W. Holotype: MZUSP 38511. Paratypes: MNRJ 11388 (1); MZUSP 38509 (1 c&s), 38510 (1, c&s). •Status uncertain -- (Huber 1992:367 [ref. 20639]). •Synonym of Pituna compacta (Myers 1927) -- (Costa 1998:81 [ref. 23792], Costa 1998:142 [ref. 23879], Lazara 2001:251 [ref. 25711], Costa in Reis et al. 2003:533 [ref. 27061]). •Valid as Pituna poranga Costa 1989 -- (Costa 2007:9 [ref. 28993]). Current status: Valid as Pituna poranga Costa 1989. Rivulidae: Rivulinae. Distribution: Araguaia basin, Goiás and Tocantins, Brazil. Habitat: freshwater.

porosus, Cynolebias Steindachner [F.] 1876:173 [125], Pl. 10 (fig. 3) [Sitzungsberichte der Kaiserlichen Akademie der Wissenschaften. Mathematisch-Naturwissenschaftliche Classe v. 74 (1. Abth.); ref. 4225] Pernambuco, Brazil. Holotype (unique): NMW 15096. On p. 125 of separate. •Valid as Cynolebias porosus Steindachner 1876 -- (Costa 1995:84 [ref. 22097], Costa 1998:238 [ref. 23578], Costa 1998:76 [ref. 23792], Lazara 2001:78 [ref. 25711], Costa in Reis et al. 2003:529 [ref. 27061], Costa 2014:93 [ref. 33510], Silva et al. 2020:14 [ref. 37809]). Current status: Valid as Cynolebias porosus Steindachner 1876. Rivulidae: Cynolebiinae. Distribution: South America: Atlantic coastal plains (Brazil). Habitat: freshwater.

portugali, Moema Costa [W. J. E. M.] 1989:224, Fig. 2 [Revista Brasileira de Biologia v. 49 (no. 1); ref. 14270] Furo do Firmino, Ilha de Maracá, Roraima, Brazil. Holotype: INPA 1334. Paratypes: MNRJ 11387 (1); MZUSP 38512 (1, c&s), 38513 (3). •Valid as Moema portugali Costa 1989 -- (Costa 1993:625 [ref. 21979], Costa 1998:79 [ref. 23792], Lazara 2001:211 [ref. 25711], Costa in Reis et al. 2003:532 [ref. 27061], Huber 2003:14 [ref. 27251], Costa 2003:167 [ref. 27617], Costa 2003:2 [ref. 27634], Valdesalici et al. 2015:129 [ref. 33902], Valdesalici 2016:66 [ref. 34174]). Current status: Valid as Moema portugali Costa 1989. Rivulidae: Rivulinae. Distribution: Branco River drainage, Amazon River basin, Brazil. Habitat: freshwater.

prognathus, Cynolebias Amato [L. H.] 1986:7, Pl. 4 (fig. 7) [Comunicaciones Zoologicas del Museo de Historia Natural de Montevideo v. 11 (no. 162); ref. 9170] Floodlands of Maravillas, 13 kilometers from route 9, La Coronilla, Rocha, Uruguay. Holotype: MHNM 2609 [not 2577 on Pl. 4]. Paratypes: MHNM 2446 (1), 2598 (2), 2605 (9). Type catalog: Loureiro et al. 2016:413 [ref. 35150]. •Valid as Cynolebias prognathus Amato 1986 -- (Malabarba 1989:159 [ref. 14217], Costa 1995:76 [ref. 22097], Berkenkamp et al. 1997:33 [ref. 23147]). •Valid as Megalebias prognathus (Amato 1986) -- (Costa 1998:76 [ref. 23792], Lazara 2001:204 [ref. 25711], Costa 2002:917 [ref. 26505], Costa in Reis et al. 2003:531 [ref. 27061]). •Valid as Austrolebias prognathus (Amato 1986) -- (Costa 2006:52 [ref. 28708], Costa 2009:188 [ref. 30417], Lanés et al. 2014:17 [ref. 33234], Litz & Koerber 2014:30 [ref. 33622], Bertaco et al. 2016:424 [ref. 34561], Nión et al. 2016:43 [ref. 35565], Loureiro et al. 2018:11 [ref. 36240], Loureiro et al. 2023:170 [ref. 40506]). •Valid as Titanolebias prognathus (Amato 1986) -- (Alonso et al. 2023:11 [ref. 40292], Koerber et al. 2023:11 [ref. 40355]). Current status: Valid as Titanolebias prognathus (Amato 1986). Rivulidae: Cynolebiinae. Distribution: South America: Lagoa Mirim basin and adjacent coastal basins, Laguna dos Patos system (southern Brazil and eastern Uruguay). Habitat: freshwater.

proximus, Melanorivulus Costa [W. J. E. M.] 2018:18, Figs. 1-2 [Zoosystematics and Evolution v. 94 (no. 1); ref. 35717] Stream crossing the road MS-306, Rio Aporé drainage, Rio Paraná Basin, Cassilândia municipality, Mato Grosso do Sul State, Brazil, 19°03'54"S, 51°49'56"W, elevation about 515 meters. Holotype: UFRJ 11681. Paratypes: CICCAA, UFRJ. Plus additional non-type material. •Valid as Melanorivulus proximus Costa 2018 -- (Volcan et al. 2018:275 [ref. 35895]). Current status: Valid as Melanorivulus proximus Costa 2018. Rivulidae: Rivulinae. Distribution: South America: upper Rio Paraná basin, central Brazilian Cerrado, Brazil. Habitat: freshwater.

pterophyllus, Hypsolebias Costa [W. J. E. M.] in Costa, Amorim & Mattos 2012:88, Figs. 11, 16 [Systematics and Biodiversity v. 10 (no. 1); ref. 31845] Seasonal pool near road BR-161, São Francisco River floodplains, 6 km north of Igarité, 11°34'27"S, 43°21'06"W, Estado da Bahia, Brazil, elevation 420 meters. Holotype: UFRJ 8376. Paratypes: BMNH 2011.11.17.3-6 (3), plus many at UFRJ. Plus addtional non-type material. •Valid as Hypsolebias pterophyllus Costa 2012 -- (Costa et al. 2013:1 [ref. 32952], Britzke et al. 2016:134 [ref. 34461], Silva et al. 2020:14 [ref. 37809]). Current status: Valid as Hypsolebias pterophyllus Costa 2012. Rivulidae: Cynolebiinae. Distribution: South America: banks of São Francisco River (Bahia State, Brazil). Habitat: freshwater.

punctatus, Rivulus Boulenger [G. A.] 1895:3 [Bollettino dei Musei di Zoologia ed Anatomia Comparata della R. Università di Torino v. 10 (no. 196); ref. 536] Colonia Risso, Paraguay. Syntypes: (5) BMNH 1895.1.30.21 (1), BMNH 1895.1.30.22 (1); MZUT 1054 [? = 2061] (3). Type catalog: Tortonese 1940:142 [ref. 21559], Huber 1992 [ref. 20639]. Costa in Reis et al. 2003:538 [ref. 27061] treats BMNH 1895.1.30 [sic] as the holotype. •Valid as Rivulus punctatus Boulenger 1895 -- (Costa 1989:525 [ref. 14319], Huber 1992:370 [ref. 20639], Costa 1995:210 [ref. 21883], Britski et al. 1999:138 [ref. 24147], Lazara 2001:283 [ref. 25711], Costa 2003:41 [ref. 26966], Costa in Reis et al. 2003:538 [ref. 27061], López et al. 2003:70 [ref. 27366], Costa 2003:2 [ref. 27635], Casciotta et al. 2003:148 [ref. 28130], Menni 2004:86 [ref. 28131], Costa 2005:71 [ref. 28192], Costa 2006:162 [ref. 28875] in subgenus Melanorivulus, Schindler & Etzel 2008:35 [ref. 29621]). •Valid as Melanorivulus punctatus (Boulenger 1895) -- (Costa 2011:241 [ref. 31655], Koerber 2014:12 [ref. 33621], Sarmiento et al. 2014:187 [ref. 35004], Mirande & Koerber 2015:52 [ref. 35117], Nielsen et al. 2016:87 [ref. 34407], Calviño et al. 2016:11 [ref. 34699], Koerber et al. 2017:72 [ref. 35267], Costa et al. 2016:270 [ref. 35405], Deprá et al. 2017:113 [ref. 35503], Volcan et al. 2018:280 [ref. 35895], Dickens 2019:168 [ref. 37135], Drawert 2023:23 [ref. 40730]). Current status: Valid as Melanorivulus punctatus (Boulenger 1895). Rivulidae: Rivulinae. Distribution: South America: Paraguay, lower Paraná and Uruguay River basins (Argentina, Bolivia, Brazil and Paraguay). Habitat: freshwater.

punctulatus, Simpsonichthys Costa [W. J. E. M.] & Brasil [G. C.] 2007:58, Figs. 1-2 [Vertebrate Zoology v. 57 (no. 1); ref. 29215] Temporary swamp adjacent to a stream tributary fo rio Bezerra, rio Preto drainage, rio São Francisco basin, near road BR-020, 15°33'01.0"S, 47°10'33.2"W, Município de Formosa, Goiás, Brazil, elevation 901 meters. Holotype: UFRJ 6478. Paratypes: UFRJ 6479 (3), 6480 (5). •Valid as Simpsonichthys punctulatus Costa & Brasil 2007 -- (Costa 2007:33 [ref. 29445], Costa 2012:314 [ref. 31750], Nielsen et al. 2017:166 [ref. 35304]). Current status: Valid as Simpsonichthys punctulatus Costa & Brasil 2007. Rivulidae: Cynolebiinae. Distribution: Tributary of Bezerra River, upper Paracatu River drainage, São Francisco River basin, Goiás, central Brazil. Habitat: freshwater.

pyropunctata, Rachovia Taphorn [D. C.] & Thomerson [J. E.] 1978:403, Fig. 9c [Acta Biologica Venezuelica v. 9 (no. 4); ref. 4337] Pool west of Lake Maracaibo, Guamo road near Hacienda Berlin, between San Felipe and Jaguasito, Zulia, Venezuela. Holotype: FMNH 85713. Paratypes: AMNH 36916 (84, 6 c&s); CAS 39379; FMNH 85712 (now 12), 85713, 85715 (7), 85720 (4), 85736-38 (10, 10, 20), 96043 (1, allotype); UF 74507 [ex FSM 24507] (46), ?UF 74508 [ex FSM 24508] (56); UMMZ 200210 (9); USNM 218056 (10). Type catalog: Ibarra & Stewart 1987:74 [ref. 12367]. •Valid as Rachovia pyropunctata Taphorn & Thomerson 1978 -- (Parenti 1981:486 [ref. 7066], Costa 1998:80 [ref. 23792], Lazara 2001:266 [ref. 25711], Costa in Reis et al. 2003:533 [ref. 27061], Berkenkamp 2020:14 [ref. 37695]). Current status: Valid as Rachovia pyropunctata Taphorn & Thomerson 1978. Rivulidae: Rivulinae. Distribution: Western Lake Maracaibo basin, Venezuela. Habitat: freshwater.

queguay, Austrolebias Serra [W. S.] & Loureiro [M.] 2018:548, Figs. 1, 2A-B, 2G, 3A [Zoosystematics and Evolution v. 94 (no. 2); ref. 36329] Wetlands of Río Queguay Grande, Estancia La Beba, Paysandú, Uruguay, 32°11'08"S, 57°26'08"W. Holotype: ZVC-P 13576. Paratypes: CAP, GP, MHNM, ZVC. •Valid as Austrolebias queguay Serra & Loureiro 2018 -- (Volcan & Severo-Neto 2019:550 [ref. 36539], Koerber et al. 2020:9 [ref. 37480], Alonso et al. 2023:10 [ref. 40292], Koerber et al. 2021:10 [ref. 38894], Koerber et al. 2023:10 [ref. 40355], Loureiro et al. 2023:168 [ref. 40506]). Current status: Valid as Austrolebias queguay Serra & Loureiro 2018. Rivulidae: Cynolebiinae. Distribution: South America: wetlands of the middle Queguay River basin, Paysandú (Uruguay). Habitat: freshwater.

quiii, Moema Huber [J. H.] 2003:11, Figs. [Freshwater and Marine Aquarium v. 26 (no. 12); ref. 27251] Rio Tambopata, 15 kilometers upriver from Puerto Maldonado, 12.733°S, 69.217°W, Fundo Shape, southeastern Peru, elevation 140 meters. Holotype: MNHN 2003-0602. Paratypes: BMNH 2003.6.22.1-3 (3), CAS 217427 (3), MNHN 2003-0603 (2), MNHNP 33556 (4), MUSM 20295 (4), Huber 2003 publication received at the American Museum of Natural History on 12 November, so the valid name is Moema quiii Huber 2003 [ortegai published on 24 Nov.] (K. Lazara, pers. comm. 3/5/2011). •Synonym of Moema ortegai Costa 2003 -- (See Costa 2004:2 [ref. 27924]). •Valid as Moema ortegai/M. quiii -- (Valdesalici et al. 2015:129 [ref. 33902], Valdesalici 2016:70 [ref. 34174], Valdesalici 2019:109 [ref. 36959]). •Valid as Moema quiii Huber 2003. Current status: Valid as Moema quiii Huber 2003. Rivulidae: Rivulinae. Distribution: Rio Madre de Dios drainage, southeastern Peru. Habitat: freshwater.

quirogai, Austrolebias Loureiro [M.], Duarte [A.] & Zarucki [M.] 2011:336, Fig. 1 [Neotropical Ichthyology v. 9 (no. 2); ref. 31392] Rio Negro basin, pound near arroyo Cordobés, 32°36'59"S, 55°19'24"W, Departmento de Cerro Largo, Uruguay. Holotype: ZVC-P 9758. Paratypes: many at ZVC. Type catalog: Loureiro et al. 2016:414 [ref. 35150]. •Valid as Austrolebias quirogai Loureiro, Duarte & Zarucki 2011 -- (Litz & Koerber 2014:30 [ref. 33622], Bertaco et al. 2016:424 [ref. 34561], Nión et al. 2016:43 [ref. 35565], Loureiro et al. 2018:11 [ref. 36240], Loureiro et al. 2023:169 [ref. 40506]). •Valid as Acantholebias quirogai (Loureiro, Duarte & Zarucki 2011) -- (Alonso et al. 2023:11 [ref. 40292], Koerber et al. 2023:10 [ref. 40355]). Current status: Valid as Acantholebias quirogai (Loureiro, Duarte & Zarucki 2011). Rivulidae: Cynolebiinae. Distribution: South America: temporary ponds, middle to upper and eastern rio Negro tributaries (Uruguay). Habitat: freshwater.

rachovii, Rivulus Ahl [E.] 1925:109 [Sitzungsberichte der Gesellschaft Naturforschender Freunde zu Berlin 1923; ref. 15525] Pará, Brazil. Lectotype: ZMB 31316. Paralectotypes: ZMB 21186 (1). Type catalog: Paepke & Seegers 1986:169 [ref. 19981]. Lectotype selected by Seegers 1984 [ref. 17455]. Types mentioned by Paepke 1995:94 [ref. 21847]. •Synonym of Rivulus santensis Köhler 1906 -- (Huber 1992:375 [ref. 20639], Lazara 2001:284 [ref. 25711], Costa in Reis et al. 2003:539 [ref. 27061], Costa 2008:197 [ref. 29962]). •Possibly valid as Rivulus rachovii Ahl 1925 -- (Huber 2017:20 [ref. 35720]). •Synonym of Atlantirivulus santensis (Köhler 1906). Current status: Synonym of Atlantirivulus santensis (Köhler 1906). Rivulidae: Rivulinae. Habitat: freshwater.

radiosus, Simpsonichthys Costa [W. J. E. M.] & Brasil [G. C.] 2004:2 [Zootaxa No. 737; ref. 28012] About 6 kilometers from confluence with Rio Paranã, about 15°20'S, 47°20'W, Rio Crixás floodplains, Est. Goías, Brazil, elevation about 800 meters. Holotype: UFRJ 6017. Paratypes: UFRJ 6018-21 (9, 6, 6, 5). •Valid as Simpsonichthys radiosus Costa & Brasil 2004 -- (Costa 2005:63 [ref. 28575], Costa 2006:17 [ref. 28620], Costa 2007:68 [ref. 29445]). •Valid as Hypsolebias radiosus (Costa & Brasil 2004) -- (based on generic placement in Costa 2011 [ref. 31654]). Current status: Valid as Hypsolebias radiosus (Costa & Brasil 2004). Rivulidae: Cynolebiinae. Distribution: Crixás floodplains, Paraná River drainage, upper Tocantins River basin, central Brazil. Habitat: freshwater.

radiseriatus, Hypsolebias Costa [W. J. E. M.] in Costa, Amorim & Mattos 2012:83, Figs. 7, 14 [Systematics and Biodiversity v. 10 (no. 1); ref. 31845] Seasonal swamp adjacent to right bank of Verde Grande River, a tributary of São Francisco River, near the village of Gado Bravo, 14°55'20"S, 43°29'56"W, Estado de Minas Gerais, Brazil, elevation 457 meters. Holotype: UFRJ 8295. Paratypes: UFRJ 8294 (4, c&s), 8296 (12), 4780 (4), 4781 (5), 8298 (5, c&s). Plus non-type specimens. •Valid as Hypsolebias radiseriatus Costa 2012 -- (Costa et al. 2013:1 [ref. 32952], Britzke et al. 2016:134 [ref. 34461]). Current status: Valid as Hypsolebias radiseriatus Costa 2012. Rivulidae: Cynolebiinae. Distribution: Verde Grande River drainage, São Francisco River system, Minas Gerais state, Brazil. Habitat: freshwater.

rectiventer, Cynolebias Costa [W. J. E. M.] 2014:87, Fig. 4 [Ichthyological Exploration of Freshwaters v. 25 (no. 1); ref. 33510] Seasonal lagoon in the floodplains of the Verde River, 10°43'20"S, 42°20'30"W, elevation 404 meters. Holotype: UFRJ 8896. Paratypes: BMNH 2013.6.23.7-8 (2), UFRJ, ZFMJ •Valid as Cynolebias rectiventer Costa 2014 -- (Silva et al. 2020:14 [ref. 37809]). Current status: Valid as Cynolebias rectiventer Costa 2014. Rivulidae: Cynolebiinae. Distribution: Verde River floodplains, São Francisco River basin, Brazil. Habitat: freshwater.

rectocaudatus, Rivulus Fels [J. F.] & de Rham [P.] 1981:66, Figs 1, 16, 19, 20. [Revue française d'Aquariologie Herpétologie v. 8 (no. 3); ref. 8607] "Vivero Forestal El Varillal", 4°04'S, 73°27'W, 34 kilometers from Iquitos on the Iquitos-Nauta road, Peru. Holotype: MHNG 2079.10. Paratypes: MHNG 2079.11 to .32 (23); MNHN 1981-1263 (6), 1981-1264 (5). Type catalog: Weber 1998:12 [ref. 32707]. Combined with a neuter genus, the adjective should be rectocaudatum. •Valid as Rivulus rectocaudatus Fels & de Rham 1981 -- (Ortega & Vari 1986:19 [ref. 9708], Huber 1992:378 [ref. 20639], Lazara 2001:283 [ref. 25711], Costa in Reis et al. 2003:539 [ref. 27061], Costa 2004:4 [ref. 27570], Costa 2004:11 [ref. 27656], Hrbek et al. 2004:570 [ref. 27910], Costa 2004:2 [ref. 27923], Costa 2006:157 [ref. 28875] in subgenus Owiyeye, Schindler & Valdesalici 2011:109 [ref. 31382], Vermeulen et al. 2013:191 [ref. 32954], Vermeulen & Mejia-Vargas 2020:34 [ref. 37938]). •Valid as Laimosemion rectocaudatum (Fels & de Rham 1981) -- (Costa 2011:240 [ref. 31655] as rectocaudatus, Vermeulen et al. 2012:188 [ref. 32253] as rectocaudatus, Costa & Bragança 2013:93 [ref. 32797] as rectocaudatus, Costa & Lazzarotto 2014:372 [ref. 33247] as rectocaudatus, Meza-Vargas et al. 2021:27 [ref. 39298]). Current status: Valid as Laimosemion rectocaudatum (Fels & de Rham 1981). Rivulidae: Rivulinae. Distribution: South America: Amazon River basin (Peru). Habitat: freshwater.

regani, Cynolebias Myers [G. S.] 1952:139 [Aquarium Journal v. 23 (no. 7); ref. 3125] Not available, name only. Subsequent validation of name not researched. •Nomen nudum in genus Cynolebias -- (Lazara 2001:78 [ref. 25711]). •Nomen nudum in synonymy of Cynolebias microphthalmus Costa & Brasil 1995 -- (Costa 2001:354 [ref. 25719], Costa in Reis et al. 2003:529 [ref. 27061]). Nomen Nudum. Current status: Synonym of Cynolebias microphthalmus Costa & Brasil 1995. Rivulidae: Cynolebiinae.

regularis, Melanorivulus Costa [W. J. E. M.] 2017:61, Fig. 6 [ZooKeys No. 645; ref. 35046] Ribeirão da Sobra, upper Rio Itiquira drainage, Rio Paraguai basin, Alto Graças municipality, Mato Grosso state, Brazil, 16°54'41"S, 53°37'55"W, elevation approximately 750 meters. Holotype: UFRJ 6878. Paratypes: CICCAA, UFRJ. •Valid as Melanorivulus regularis Costa 2017 -- (Deprá et al. 2017:121 [ref. 35503]). Current status: Valid as Melanorivulus regularis Costa 2017. Rivulidae: Rivulinae. Distribution: Upper Rio Itiquira drainage, Rio Paraguai basin, Mato Grosso, Brazil. Habitat: freshwater.

reicherti, Cynolebias Loureiro [M.] & García [G.] 2004:16, Figs. 2A-B [Acta Zoológica Lilloana v. 48 (no. 1-2); ref. 28591] Temporary pool 300 meters east of Rte 18, 1 kilometer north of Vergara City, about 32°55'S, 53°54'W, Dept. de Treinta y Tres, Uruguay. Holotype: ZVC-P 4362. Paratypes: ZVC-P 4363 (18, 9 c&s), 4365 (5, 2 c&s), 4366 (5), 4367 (5), 4370 (10). Type catalog: Loureiro et al. 2016:414 [ref. 35150]. •Synonym of Austrolebias charrua Costa & Cheffe 2001 -- (Costa 2006:120 [ref. 28708]). •Valid as Austrolebias reicherti (Loureiro & García 2004) -- (Loureiro & García 2008:10 [ref. 30099], Volcan et al. 2014:170 [ref. 33543], Litz & Koerber 2014:30 [ref. 33622], Bertaco et al. 2016:424 [ref. 34561], Nión et al. 2016:43 [ref. 35565] with authors as Loureiro & García 2004, Costa et al. 2017:142 [ref. 35626], Loureiro et al. 2018:11 [ref. 36240], Volcan et al. 2021:104 [ref. 38292] as aff. reicherti, Loureiro et al. 2023:167 [ref. 40506]). •Valid as Garcialebias reicherti (Loureiro & García 2004) -- (Alonso et al. 2023:13 [ref. 40292], Koerber et al. 2023:10 [ref. 40355]). Current status: Valid as Garcialebias reicherti (Loureiro & García 2004). Rivulidae: Cynolebiinae. Distribution: South America: southern Laguna Merín basin and adjacent coastal plains on the border of Brazil and Uruguay. Habitat: freshwater.

reticulatus, Simpsonichthys Costa [W. J. E. M.] & Nielsen [D. T. B.] 2003:120, Figs. 1-2 [aqua, Journal of Ichthyology and Aquatic Biology v. 7 (no. 3); ref. 27246] Altamira, about 3°15'S, 52°20'W [3°13'34.5"S, 52°12'26.1"W], Estado do Pará, Brazil. Holotype: MCP 34090. Paratypes: UFRJ 5871 (2, 1 c&s). •Valid as Simpsonichthys reticulatus Costa & Nielsen 2003 -- (Costa 2006:17 [ref. 28620], Costa 2007:42 [ref. 29445], Costa & Brasil 2008:245 [ref. 29968]). •Valid as Spectrolebias reticulatus (Costa & Nielsen 2003) -- (Nielsen 2013:81 [ref. 32696], Costa & Amorim 2018:366 [ref. 36019]). Current status: Valid as Spectrolebias reticulatus (Costa & Nielsen 2003). Rivulidae: Cynolebiinae. Distribution: Lower Xingu River floodplains, Brazilian Amazon, Pará, Brazil. Habitat: freshwater.

ribeirensis, Atlantirivulus Costa [W. J. E. M.] 2014:17, Figs. 8-9 [Vertebrate Zoology v. 64 (no. 1); ref. 33307] Estado de São Paulo, Município de Juquiá, swamp in the road about 5 km W from Juquiá, 24°20′00″S ,47°38′ 51″ W, Brazil. Holotype: UFRJ 9800. Paratypes: UFRF 6326 (3), 6329 (11), 6330 (1), 6605 (5), 6607 (2). Plus non-type specimens. •Valid as Atlantirivulus ribeirensis Costa 2014. Current status: Valid as Atlantirivulus ribeirensis Costa 2014. Rivulidae: Rivulinae. Distribution: Ribeira de Iguape river basin, Brazil. Habitat: freshwater.

ribesrubrum, Rivulus Vermeulen [F. B. M.] 2013:53, Figs. 6-7 [Killi-Data Series 2013; ref. 33089] Tributary of right bank of Río La Miel, San Miguel, Caldas Departimento, central Colombia, 05°36'28"N, 74°99'35"W, elevation 290 meters. Holotype (unique): IAVHP 11256. Paratype: RMNH.PISC 36366 (1). Type catalog: DoNascimiento et al. 2016:430 [ref. 34787]. •Valid as Rivulus ribesrubrum Vermeulen 2013 -- (DoNascimiento et al. 2017:102 [ref. 35633], Gomes 2023:17 [ref. 40174]). •Valid as Cynodonichthys ribesrubrum (Vermeulen 2013). Current status: Valid as Cynodonichthys ribesrubrum (Vermeulen 2013). Rivulidae: Rivulinae. Distribution: South America: upper Río La Miel drainage, Colombia. Habitat: freshwater.

riograndensis, Rivulus Costa [W. J. E. M.] & Lanés [L. E. K.] 2009:92, Fig. 1 [Ichthyological Exploration of Freshwaters v. 20 (no. 1); ref. 30256] Pai João swamp, Parque Nacional da Lagoa do Peixe, 31°03'24"S, 50°49'40"W, Estado do Rio Grande do Sul, Brazil. Holotype: UFRJ 6639. Paratypes: MCP 14977 (1), 22485 (2); UFRGS 5809 (9 + 3 c&s), 6674 (2); UFRJ 6640 (4), Plus non-type mmaerial. •Valid as Atlantirivulus riograndensis (Costa & Lanés 2009) -- (Costa 2011:244 [ref. 31655], Costa 2014:19 [ref. 33307], Bertaco et al. 2016:423 [ref. 34561], Loureiro et al. 2018:11 [ref. 36240]). Current status: Valid as Atlantirivulus riograndensis (Costa & Lanés 2009). Rivulidae: Rivulinae. Distribution: Patos lagoon basin and adjacent coastal plains, Rio Grande do Sul state, southern Brazil. Habitat: freshwater.

robustus, Cynolebias Günther [A.] 1883:140 [Annals and Magazine of Natural History (Series 5) v. 11 (no. 62) (art. 18); ref. 21260] Within 10 miles of San Antonio, La Plata, Province Buenos Aires, Argentina. Holotype (unique): BMNH 1879.6.28.12. •Synonym of Cynolebias elongatus Steindachner 1881 -- (Costa 1995:78 [ref. 22097]). •Synonym of Austrolebias bellotti (Steindachner 1881) -- (Lazara 2001:60 [ref. 25711]). •Valid as Austrolebias robustus (Günther 1883) -- (Costa 2002:917 [ref. 26505], Calviño 2003:1 [ref. 26595], Costa in Reis et al. 2003:528 [ref. 27061], Costa et al. 2004:15 [ref. 27657], Calviño 2005:15 [ref. 28325], Calviño 2006:183 [ref. 28679], Costa 2006:37 [ref. 28708], Costa 2011:100 [ref. 31504], Koerber 2011:7 [ref. 31122], Koerber 2014:12 [ref. 33621], Mirande & Koerber 2015:51 [ref. 35117], Koerber et al. 2017:7 [ref. 35083], Koerber et al. 2017:8 [ref. 35632], Loureiro et al. 2018:11 [ref. 36240], García et al. 2019:[12] [ref. 36487], Koerber et al. 2019:9 [ref. 36736]). •Valid as Cypholebias robustus (Günther 1883) -- (Alonso et al. 2023:12 [ref. 40292], Koerber et al. 2023:4 [ref. 40368]). Current status: Valid as Cypholebias robustus (Günther 1883). Rivulidae: Cynolebiinae. Distribution: South America: La Plata River basin (Argentina). Habitat: freshwater.

robustus, Rivulus Miller [R. R.] & Hubbs [C. L.] 1974:865, Figs. 1-3 [Copeia 1974 (no. 4); ref. 7523] Pool north of Arroyo Zacatispán, about 5 kilometers south of Papaloapan (now El Hule), Oaxaca, Mexico. Holotype: UMMZ 124278. Paratypes: (107) UF 16212 (4); UMMZ 124231 (5), 124252 (3), 124279 (4), 146156 (1), 188784 (8), 194706 (62, 8 c&s); USNM 212230 [ex UMMZ 194706] (20). Appeared first as nomen nudum (name only) in Gordon 1947:128 [ref. 38365], based on an unpublished revisionary study by Miller & Gordon. •Valid as Rivulus robustus Miller & Hubbs 1974 -- (Huber 1992:382 [ref. 20639], Espinosa Pérez et al. 1993:37 [ref. 22290]). •Valid as Millerichthys robustus (Miller & Hubbs 1974) -- (Costa 1995:19 [ref. 22097], Costa 1998:79 [ref. 23792], Lazara 2001:209 [ref. 25711], Costa in Reis et al. 2003:532 [ref. 27061], Nelson et al. 2004:101 [ref. 27807], Miller 2006:207 [ref. 28615], Scharpf 2007:11 [ref. 30398], Page et al. 2013:103 [ref. 32708], Lozano-Vilano & De la Maza-Benignos 2016:5 [ref. 35401], Page et al. 2023:140 [ref. 40505]). Current status: Valid as Millerichthys robustus (Miller & Hubbs 1974). Rivulidae: Rivulinae. Distribution: Southern North America: Papaloapan and Coatzacoalcos River basins (Mexico). IUCN (2019): Endangered. Habitat: freshwater.

rogoaguae, Rivulus Pearson [N. E.] & Myers [G. S.] in Pearson 1924:51 [Indiana University Studies v. 11 (no. 64); ref. 3396] Lago Rogoagua, Bolivia. Holotype: CAS 42531 [ex IU 17257]. Paratypes: CAS 42532 [ex IU 17257] (40, now 39). •Valid as Trigonectes rogoaguae (Pearson & Myers 1924) -- (Costa 1990:144 [ref. 14542], Costa 1998:78 [ref. 23792], Lazara 2001:309 [ref. 25711], Costa in Reis et al. 2003:543 [ref. 27061], Sarmiento et al. 2014:187 [ref. 35004], Drawert 2023:42 [ref. 40730]). Current status: Valid as Trigonectes rogoaguae (Pearson & Myers 1924). Rivulidae: Rivulinae. Distribution: South America: Mamoré River basin (Bolivia). Habitat: freshwater.

roloffi, Rivulus Roloff [E.] (ex Trewavas) 1938:597, Fig. 2 [Wochenschrift für Aquarien- und Terrarienkunde v. 35 (no. 38); ref. 20645] Small brook at Arbol Plantation, near Villa Altagracia [Villa Alta Gracia], on road between Ciudad Trujilio [Santo Domingo de Guzmán] and Puerto Plata, Dominican Republic, 18°41'39"N, 70°11'15"W. Lectotype: BMNH 1947.11.27:1-3. Paralectotypes: BMNH 1947.11.27.1-3 (2). Also described as new in Trewavas 1948:408 [ref. 13077]. Apparently characters used by Roloff are different from those of Trewavas, so authorship is Roloff (current authors) rather than Trewavas in Roloff. •Status uncertain -- (Lee et al. 1983:61 [ref. 22527]). •Valid as Rivulus roloffi Roloff 1938 -- (Huber 1992:385 [ref. 20639], Lazara 2001:283 [ref. 25711], Costa in Reis et al. 2003:539 [ref. 27061], Costa 2006:139 [ref. 28875], Costa 2011:239 [ref. 31655] as "Rivulus" roloffi). Current status: Valid as Rivulus roloffi Roloff 1938. Rivulidae: Rivulinae. Distribution: River basins of Dominican Republic. Habitat: freshwater.

romeri, Rivulus Costa [W. J. E. M.] 2003:176, Figs. 1-3 [Arquivos do Museu Nacional de Rio de Janeiro v. 61 (no. 3); ref. 27578] Brook tributary to Igarapé Iauiari, about 0°14.31'N, 68°03.48'W, tributary of Uaupés River which is a tributary of Negro River, Amazon basin, Amazonas, northern Brazil. Holotype: MCP 29751. Paratypes: MCP 29752 (1); UFRJ 5447 (2), 5448 (4, c&s). Named after U. Römer, so being based on a German name the name has to be corrected to roemeri (ICZN Art. 32.5.1). •Valid as Rivulus roemeri Costa 2003 (often seen as romeri) -- (Costa 2004:4 [ref. 27570], Costa 2004:11 [ref. 27656], Costa 2004:2 [ref. 27923], Costa 2006:157 [ref. 28875] in subgenus Owiyeye, Schindler & Valdesalici 2011:109 [ref. 31382], Vermeulen 2023:109 [ref. 40177]). •Valid as Laimosemion romeri (Costa 2003) -- (Costa 2011:240 [ref. 31655], Costa & Bragança 2013:93 [ref. 32797], Costa & Lazzarotto 2014:372 [ref. 33247], Valdesalici 2016:279 [ref. 34270], Valdesalici & Nielsen 2017:102 [ref. 35496]). •Valid as Laimosemion roemeri (Costa 2003). Current status: Valid as Laimosemion roemeri (Costa 2003). Rivulidae: Rivulinae. Distribution: Upper Negro River basin, northern Brazil. Habitat: freshwater.

rondoni, Rivulus Miranda Ribeiro [A. de] 1920:7, Unnum. Pls. 1-2 [Peixes (excl. Characinidae) No. 58 (Annexo 5); ref. 3727] Cáceres, antiga Villa Maria, Matto Grosso, Lagoa da Imbaúva, Brazil. Syntypes: (3) lost. Costa in Reis et al. 2003:543 [ref. 27061] list a lost holotype at MNRJ. •Synonym of Trigonectes balzanii (Perugia 1891) -- (Costa 1990:136 [ref. 14542], Lazara 2001:309 [ref. 25711], Costa in Reis et al. 2003:543 [ref. 27061], Mirande & Koerber 2015:52 [ref. 35117], Koerber et al. 2017:72 [ref. 35267]). Current status: Synonym of Trigonectes balzanii (Perugia 1891). Rivulidae: Rivulinae. Habitat: freshwater.

roraima, Anablepsoides Costa [W. J. E. M.], Bragança [P. H. N.] & Amorim [P. F.] 2013:286, Fig. 2 [Vertebrate Zoology v. 63 (no. 3); ref. 33108] Estado de Roraima, Município de Bonfim, stream 87 km NE of Boa Vista, road BR-401, Tacutu river drainage, part of Branco river drainage, middle Amazonas river basin, Brazil, 3°15′39″N, 60°04′ 57"W. Holotype: UFRJ 9571. Paratypes: UFRJ 9572 (5), 9573 (14). Plus additional non-type material. •Valid as Anablepsoides roraima Costa, Bragança & Amorim 2013. Current status: Valid as Anablepsoides roraima Costa, Bragança & Amorim 2013. Rivulidae: Rivulinae. Distribution: Tacutu River drainage, Brazil. Habitat: freshwater.

rosaceus, Simpsonichthys Costa [W. J. E. M.], Nielsen [D. T. B.] & de Luca [A. C.] 2001:28, Fig. [Aquarium (Brasil) v. 4 (no. 26); ref. 25934] Poça temporária perto do rio Pardo, estrada entre Potiguará e Itapetinga, Bahia, Brazil [ca. 15°30'S, 39°50'W, elevation about 170 m]. Holotype: MZUSP 62572. Paratypes: MZUSP 62573 (5); UFRJ 5146-47 (20, 4). •Valid as Simpsonichthys rosaceus Costa, Nielsen & de Luca 2001 -- (Costa in Reis et al. 2003:542 [ref. 27061], Costa 2004:6 [ref. 27569], Costa 2007:22 [ref. 29445], Costa & Lima 2010:205 [ref. 31041] in subgenus Ophthalmolebias). •Valid as Ophthalmolebias rosaceus (Costa, Nielsen & de Luca 2001) -- (Silva et al. 2020:15 [ref. 37809], Vieira-Guimarães et al. 2024:55 [ref. 41258]). Current status: Valid as Ophthalmolebias rosaceus (Costa, Nielsen & de Luca 2001). Rivulidae: Cynolebiinae. Distribution: South America: middle Pardo River basin , Bahia State (Brazil). Habitat: freshwater.

roseus, Cynolebias Costa [W. J. E. M.] 2014:85, Fig. 3 [Ichthyological Exploration of Freshwaters v. 25 (no. 1); ref. 33510] Temporary pools close to road BA-161, about 15 km north of the town of Barra, São Francisco River floodplains,10°58'28"S, 43°03'00"W, Brazil, elevation 410 meters. Holotype: UFRJ 9330. Paratypes: UFRJ 9331 (4), 9332 (11), 6724 (4). •Valid as Cynolebias roseus Costa 2014 -- (Silva et al. 2020:14 [ref. 37809]). Current status: Valid as Cynolebias roseus Costa 2014. Rivulidae: Cynolebiinae. Distribution: South America: temporary pools near Barra, São Francisco River Basin (Brazil). Habitat: freshwater.

rossoi, Rivulus Costa [W. J. E. M.] 2005:74, Fig. 5 [Neotropical Ichthyology v. 3 (no. 1); ref. 28192] Stream at road BR-060, 21.5 kilometers southwest from Campo Grande, Inhanduí drainage, rio Paraná basin, about 20°40'S, 54°40'W, Estado de Mato Grosso do Sul, Brazil, elevation about 500 meters. Holotype: UFRJ 5976. Paratypes: MCP 36122 (2); UFRJ 5923 (1), 5977 (7), 5978 (4, c&s). •Valid as Rivulus rossoi Costa 2005 -- (Costa 2006:162 [ref. 28875] in subgenus Melanorivulus). •Valid as Melanorivulus rossoi (Costa 2005) -- (Costa 2011:241 [ref. 31655], Volcan et al. 2018:280 [ref. 35895]). Current status: Valid as Melanorivulus rossoi (Costa 2005). Rivulidae: Rivulinae. Distribution: Inhanduí River drainage, Paraná River basin, Brazil. Habitat: freshwater.

rubripunctatus, Rivulus isthmensis Bussing [W. A.] 1980:334, Figs. 1C, 3D, 4D [Brenesia No. 17; ref. 8732] Pond 1/2 kilometer southwest of Puerto Vargas, Punta Cahuita, Limón Province, Costa Rica, elevation 2 meters. Holotype: LACM 38278-1. Paratypes: LACM 38278-2 (20); UCR 212-1 (28), 791-1 (4), 892-1 (147), 892-2 (22), 893-6 (1), 894-1 (1), 896-1 (10), 897-1 (23), 1017-4 (1), 1018-1 (8); USNM 219777 (10). Type catalog: Angulo et al. 2015:373 [ref. 35212]. •Status uncertain -- (Huber 1992:388 [ref. 20639]). •Synonym of Rivulus isthmensis Garman 1895, but a valid subspecies as described -- (Bussing 1998:177 [ref. 24179], Lazara 2001:278 [ref. 25711]). •Valid as Rivulus rubripunctatus Bussing 1980 -- (Berkenkamp & Etzel 1999:64 [ref. 23985], Costa in Reis et al. 2003:539 [ref. 27061], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys). •Valid as Cynodonichthys rubripunctatus (Bussing 1980) -- (Costa 2011:242 [ref. 31655], Angulo et al. 2013:995 [ref. 33194]). Current status: Valid as Cynodonichthys rubripunctatus (Bussing 1980). Rivulidae: Rivulinae. Distribution: Atlantic river basins, Costa Rica. Habitat: freshwater.

rubrocaudatus, Pterolebias Seegers [L.] 1984:243, Figs. 1-2 [Bonner Zoologische Beiträge v. 35 (nos 1-3); ref. 17453] Río Tambopata, Río Madre de Dios drainage, 7 kilometers from Puerto Maldonado, southeastern Peru. Holotype: ZFMK 13413. Paratypes: ZFMK 13414 (1). Type catalog: Herder et al. 2010:125 [ref. 31087]. Combined with a feminine genus, the adjective should be rubrocaudata. •Valid as Pterolebias rubrocaudatus Seegers 1984 -- (Ortega & Vari 1986:19 [ref. 9708]). •Valid as Aphyolebias rubrocaudatus (Seegers 1984) -- (Costa 1998:78 [ref. 23792], Lazara 2001:5 [ref. 25711], Costa in Reis et al. 2003:526 [ref. 27061], Costa 2003:156 [ref. 27616]). •Valid as Moema rubrocaudata (Seegers 1984) -- (Valdesalici et al. 2015:129 [ref. 33902] as rubrocaudatus, Valdesalici 2016:70 [ref. 34174] as rubrocaudatus). Current status: Valid as Moema rubrocaudata (Seegers 1984). Rivulidae: Rivulinae. Distribution: Madre de Dios River basin, Amazon River basin, Peru. Habitat: freshwater, brackish.

rubrofasciatus, Neofundulus Costa [W. J. E. M.] 2015:17, Fig. 3 [Vertebrate Zoology v. 65 (no. 1); ref. 33783] Estado de Mato Grosso de Sul, Municipio de Bodoquena, temporary pool about 18 km west of the village of Bodoquena, road MS-339, Salobra river floodplains, Miranda River drainage, Paraguay River basin, 20°29'42"N, 56°48'37"W, altitude about 170 meters. Holotype: UFRJ 10083. Paratypes: UFRJ. Plus additional non-type material. •Valid as Neofundulus rubrofasciatus Costa 2015. Current status: Valid as Neofundulus rubrofasciatus Costa 2015. Rivulidae: Rivulinae. Distribution: Salobra River floodplains, Brazil. Habitat: freshwater.

rubrolineatus, Rivulus Fels [J. F.] & de Rham [P.] 1981:66, Fig. [Revue française d'Aquariologie Herpétologie v. 8 (no. 3); ref. 8607] 14 kilometers from Jenaro Herrera, on the way to Colonia Angamos, 4°53'S, 73°41'W, Peru. Holotype: MHNG 2079.46. Paratypes: MHNG 2079.47 to .56 (10), MNHN 1981-1267 (2) and 1268 (8). Type catalog: Weber 1998:12 [ref. 32707]. •Doubtfully valid as Rivulus rubrolineatus Fels & de Rham 1981 -- (Huber 1992:391 [ref. 20639]). •Valid as Rivulus rubrolineatus Fels & de Rham 1981 -- (Ortega & Vari 1986:19 [ref. 9708], Lazara 2001:283 [ref. 25711], Costa 2006:139, 165 [ref. 28875] in subgenus Cynodonichthys, Valdesalici & Schindler 2011:313 [ref. 31673] in subgenus Cynodonichthys, Barriga Salazar 2014:117 [ref. 35745]). •Valid as Anablepsoides rubrolineatus (Fels & de Rham 1981) -- (Costa 2011:243 [ref. 31655], Costa 2013:346 [ref. 32528], Valdesalici & Schindler 2013:296 [ref. 33109], Nielsen et al. 2016:70 [ref. 34406], Nielsen 2016:166 [ref. 34861], DoNascimiento et al. 2017:101 [ref. 35633], Valdesalici & Gil 2019:152 [ref. 37074], Meza-Vargas et al. 2021:27 [ref. 39298]). Current status: Valid as Anablepsoides rubrolineatus (Fels & de Rham 1981). Rivulidae: Rivulinae. Distribution: South America: upper Amazon basin (Colombia, Ecuador and Peru). Habitat: freshwater.

rubromarginatus, Rivulus Costa [W. J. E. M.] 2007:58, Figs. 4-5 [aqua, International Journal of Ichthyology v. 13 (no. 2); ref. 29394] Stream tributary to Rio Espingarda, Rio de Pexie drainage, Rio Araguaia basin at road GO-164 crossing, Goiás State, Brazil, 14°28'27.5"S, 50°28'21.7"W, elevation 275 meters. Holotype: UFRJ 6474. Paratypes: (20) UFRJ 6475 (2), 6476 (14), 6477 (4). •Valid as Rivulus rubromarginatus Costa 2007 -- (Costa 2010:369 [ref. 30690], Costa 2010:197 [ref. 31043]). •Valid as Melanorivulus rubromarginatus (Costa 2007) -- (Costa 2011:241 [ref. 31655], Costa 2016:145 [ref. 34900], Nielsen 2017:67 [ref. 35340], Nielsen & Britzke 2019:42 [ref. 36525]). Current status: Valid as Melanorivulus rubromarginatus (Costa 2007). Rivulidae: Rivulinae. Distribution: Middle Araguaia River basin, central Brazil. Habitat: freshwater.

rubromarginatus, Trigonectes Costa [W. J. E. M.] 1990:145, Figs. 13-14 [Ichthyological Exploration of Freshwaters v. 1 (no. 2); ref. 14542] Aruana, Goiás, Brazil. Holotype: MZUSP 37194. Paratypes: MNRJ 11311 (3), 11700 (2); MZUSP 35417 (3), 38455 (1, c&s). •Valid as Trigonectes rubromarginatus Costa 1990 -- (Murphy & Collier 1997:797 [ref. 25585], Costa 1998:78 [ref. 23792], Lazara 2001:310 [ref. 25711], Costa et al. 2003:144 [ref. 26946], Costa in Reis et al. 2003:543 [ref. 27061]). Current status: Valid as Trigonectes rubromarginatus Costa 1990. Rivulidae: Rivulinae. Distribution: Araguaia River basin, Brazil. Habitat: freshwater.

rubroreticulatus, Melanorivulus Costa [W. J. E. M.], Amorim [P. F.] & Bragança [P. H. N.] 2014:194, Figs. 1-2 [Vertebrate Zoology v. 64 (no. 2); ref. 33400] Estado do Pará: Município de Altamira: swamp close to the road to the Altamira airport, lower Xingu river drainage, southern Amazonas river basin, 3°14′02″S, 52°14′05″W, Brazil, altitude about 100 meters. Holotype: UFRJ 9950. Paratypes: UFRJ. •Valid as Melanorivulus rubroreticulatus Costa, Amorim & Bragança 2014 -- (Costa 2016:128 [ref. 34900], Costa et al. 2016:270 [ref. 35405], Nielsen 2017:66 [ref. 35340], Nielsen & Britzke 2019:41 [ref. 36525]). Current status: Valid as Melanorivulus rubroreticulatus Costa, Amorim & Bragança 2014. Rivulidae: Rivulinae. Distribution: Lower Xingu River drainage, northern Brazil. Habitat: freshwater.

rufus, Simpsonichthys Costa [W. J. E. M.], Nielsen [D. T. B.] & de Luca [A. C.] 2001:29, Fig. [Aquarium (Brasil) v. 4 (no. 26); ref. 25934] Temporary pool in vicinity of Riacho do Barro, Ibiaí, in floodplain of Río São Francisco, Minas Gerais State, Brazil. Holotype: MZUSP 61234. Paratypes: MZUSP 61235 (1); UFRJ 5110-13 (3, 2, 3, 4). Also appeared as new with description in Costa & Nielsen 2001:8 [ref. 26580]; earliest not determined. •Valid as Simpsonichthys rufus Costa, Nielsen & de Luca 2001 -- (Costa in Reis et al. 2003:542 [ref. 27061], Costa & Brasil 2004:2 [ref. 28012] with authors as Costa & Nielsen, Costa 2005:63 [ref. 28575], Costa 2006:17 [ref. 28620], Costa 2007:59 [ref. 29445]). •Valid as Hypsolebias rufus (Costa, Nielsen & de Luca 2001) -- (based on generic placement in Costa 2011 [ref. 31654]). Current status: Valid as Hypsolebias rufus (Costa, Nielsen & de Luca 2001). Rivulidae: Cynolebiinae. Distribution: Middle São Francisco River basin, Minas Gerais State, Brazil. Habitat: freshwater.

rupununi, Austrofundulus Hrbek [T.], Taphorn [D. C.] & Thomerson [J. E.] 2005:15, Figs. 7-8 [Zootaxa No. 825; ref. 28063] Arapari area on Louis Orella's Manari Ranch, about 4 miles due west of ranch house, 9th District, Guyana. Holotype: FMNH 108226 [ex FMNH 92580]. Paratypes: FMNH 92580 (23), MCNG 52001 (4), UMMA uncat. (1), UMMZ uncat. (2). •Valid as Austrofundulus rupununi Hrbek, Taphorn & Thomerson 2005 -- (Taphorn et al. 2022:36 [ref. 41297]). Current status: Valid as Austrofundulus rupununi Hrbek, Taphorn & Thomerson 2005. Rivulidae: Rivulinae. Distribution: South America: Rupununi savannah (Guyana) endemic. Habitat: freshwater.

rutilicaudus, Rivulus Costa [W. J. E. M.] 2005:77, Figs. 8-9 [Neotropical Ichthyology v. 3 (no. 1); ref. 28192] Município de Serranópolis, rio Verde floodplains, rio Paraná basin, road BR-060, 18°22'31.5"S, 52°00'59.5"W, Estafo de Goiás, Brazil, elevation 531 meters. Holotype: UFRJ 5965. Paratypes: MCP 36124 (2); UFRJ 5966 (11), 5967 (3, c&s). Plus non-type specimens. •Valid as Rivulus rutilicaudus Costa 2005 -- (Costa 2006:162 [ref. 28875] in subgenus Melanorivulus, Costa 2008:86 [ref. 29717], Costa 2010:197 [ref. 31043]). •Valid as Melanorivulus rutilicaudus (Costa 2005) -- (Costa 2011:241 [ref. 31655], Nielsen et al. 2016:87 [ref. 34407], Costa et al. 2016:270 [ref. 35405], Volcan et al. 2017:92 [ref. 35156], Costa 2018:25 [ref. 35717], Volcan et al. 2018:275 [ref. 35895]). Current status: Valid as Melanorivulus rutilicaudus (Costa 2005). Rivulidae: Rivulinae. Distribution: Verde River floodplains, Paraná River basin, Goiás, Brazil. Habitat: freshwater.

salmonicaudus, Rivulus Costa [W. J. E. M.] 2007:56, Figs. 1-2 [aqua, International Journal of Ichthyology v. 13 (no. 2); ref. 29394] Dom Bill creek, tributary to Rio Araguaia at road BR-070 crossing, ca. 44 kilometers west of Aparecida do Rio Claro, Montes Claros de Goiás, Goiás State, Brazil, 15°53'10.8"S, 51°43.23.8"W, elevation 320 meters. Holotype: MNRJ 6481. Paratypes: (37) MNRJ 1567 (5), 1575 (3), 6419 (20), 6420 (3), 6482 (6). •Valid as Rivulus salmonicaudus Costa 2007 -- (Costa 2010:369 [ref. 30690]). •Valid as Melanorivulus salmonicaudus (Costa 2007) -- (Costa 2011:241 [ref. 31655], Costa 2016:133 [ref. 34900], Costa et al. 2016:270 [ref. 35405], Nielsen 2017:66 [ref. 35340], Nielsen & Britzke 2019:42 [ref. 36525]). Current status: Valid as Melanorivulus salmonicaudus (Costa 2007). Rivulidae: Rivulinae. Distribution: Middle Araguaia River drainage, central Brazil. Habitat: freshwater.

salviai, Austrolebias Costa [W. J. E. M.], Litz [T.] & Laurino [P.] in Costa 2006:137, Fig. 51 [Zootaxa No. 1213; ref. 28708] Paso del Dragón, temporary swamp near río Tacuari, laguna Merín basin, 32°45.95'S, 53°43.19'W, Treinta y Tres Province, Uruguay. Holotype: MUNH [MUNHINA] 3208. Paratypes: CIMC 9567 (6); MUNH 3209 (2), 3210 (7); UFRJ 6169 (8), 6170 (4, c&s), 6171 (2); ZSM 33389 (8), 33390 (4). Type catalog: Neumann 2011:276 [ref. 31652]. •Synonym of Austrolebias reicherti (Loureiro & García 2004) -- (Loureiro & García 2008:10 [ref. 30099], Litz & Koerber 2014:30 [ref. 33622]). •Possibly valid as Austrolebias salviai Costa, Litz & Laurino 2006 -- (Costa et al. 2017:147 [ref. 35626]). •Synonym of Garcialebias reicherti (Loureiro & García 2004). Current status: Synonym of Garcialebias reicherti (Loureiro & García 2004). Rivulidae: Cynolebiinae. Habitat: freshwater.

sandrii, Gynopoecilus Faria [A.] & Muller [H.] 1937:98, Fig. 1 [Revista Naval No. 3; ref. 19184] Rio de Janeiro State, Brazil. Syntypes: (?5, lost). Suppressed for purposes of priority but not homonymy; placed on Official Index (Opinion 1762); same as Cynolebias splendens Myers 1942. Original genus an error for Cynopoecilus. •Valid as Cynolebias sandrii (Faria & Muller 1937) -- (Costa & Lacerda 1988:129 [ref. 19183], Costa 1995:93 [ref. 22097]). •Valid as Leptolebias sandrii (Faria & Muller 1937) -- (Costa 1998:73 [ref. 23792]). •Synonym of Leptolebias splendens (Myers 1942) -- (Lazara 2001:195 [ref. 25711], Costa in Reis et al. 2003:531 [ref. 27061]). •Synonym of Leptopanchax splendens (Myers 1942). Suppressed. Current status: Synonym of Leptopanchax splendens (Myers 1942). Rivulidae: Cynolebiinae. Habitat: freshwater.

sanguineus, Leptopanchax Costa [W. J. E. M.] 2019:75, Figs. 1-2A [ZooKeys No. 867; ref. 36869] Temporary swamp in Reserva Particular do Patrimônio Natural Campo Escoteiro Geraldo Hugo Nunes, Magé River basin near the village of Citrolândia, Magé Municipality, Rio de Janeiro State, Brazil, 22°34'57"S, 43°02'08"W, elevation about 30 meters. Holotype: MNRJ 51331. Paratypes: MNRJ 11413 (2), MZUSP 38443 (1). •Valid as Leptopanchax sanguineus Costa 2019. Current status: Valid as Leptopanchax sanguineus Costa 2019. Rivulidae: Cynolebiinae. Distribution: Magé River basina, Rio de Janeiro State, Brazil. Habitat: freshwater.

santanae, Cynolebias Shibatta [O. A.] & Garavello [J. C.] 1992:182, Fig. 5 [Comunicações do Museu de Ciências da PUCRS, Série Zoologia v. 5 (no. 11); ref. 21420] Right bank of ribeirão Sant'ana [Santana], Distrito Federal, 750 meters from border of Distrito Federal with Goiás, Brazil, [16°02'31"S, 47°45'38"W]. Holotype: MZUSP 43777. Paratypes: MCP 15453 (4), MZUSP 43778 (41). •Valid as Simpsonichthys santanae (Shibatta & Garavello 1992) -- (Costa & Brasil 1996:95 [ref. 22917], Costa 1996:130 [ref. 25271], Costa 1998:75 [ref. 23792], Lazara 2001:298 [ref. 25711], Costa et al. 2003:140 [ref. 26946], Costa in Reis et al. 2003:542 [ref. 27061], Costa 2006:17 [ref. 28620], Costa & Brasil 2006:221 [ref. 28843], Costa & Brasil 2007:60 [ref. 29215], Costa 2007:200 [ref. 29338], Costa 2007:38 [ref. 29445], Costa & Nielsen 2007:69 [ref. 35757], Costa 2012:314 [ref. 31750], Nielsen et al. 2017:166 [ref. 35304], Nielsen et al. 2017:166 [ref. 35304], Loureiro et al. 2018:11 [ref. 36240]). Current status: Valid as Simpsonichthys santanae (Shibatta & Garavello 1992). Rivulidae: Cynolebiinae. Distribution: Ribeirão Santana floodplains, upper Paraná River basin, central Brazil. Habitat: freshwater.

santensis, Rivulus elegans var. Köhler [W.] 1906:408, Fig. [Blätter für Aquarien- und Terrarienkunde v. 17 (no. 41); ref. 19678] Western surroundings of Santos, near Pedro Taques, Estado de São Paulo, Brazil [Santos, Brazil]. Neotype: MNHN 1991-6856. Neotype designation by Huber 1992:396 [ref. 20639]. MNHN 1991-6857 (1) listed as a "Paraneotype" and many others. •Synonym of Rivulus elegans Steindachner 1880, but a valid subspecies as described -- (Costa 1991:582 [ref. 20033], Huber 1992:396 [ref. 20639]). •Valid as Rivulus santensis Köhler 1906 -- (Lazara 2001:283 [ref. 25711], Costa in Reis et al. 2003:539 [ref. 27061], Costa 2004:105 [ref. 27824], Costa 2004:105 [ref. 27824], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys, Costa 2007:181 [ref. 29203], Costa 2007:128 [ref. 29225], Costa 2008:135 [ref. 29871], Costa 2008:197 [ref. 29962], Costa & Lanés 2009:94 [ref. 30256]). •Valid as Atlantirivulus santensis (Köhler 1906) -- (Costa 2011:244 [ref. 31655], Costa 2014:19 [ref. 33307], Volcan et al. 2024:98 [ref. 41345]). Current status: Valid as Atlantirivulus santensis (Köhler 1906). Rivulidae: Rivulinae. Distribution: South America: Atlantic coastal river basins, eastern Brazil. Habitat: freshwater.

sape, Rivulus Lasso-Alcalá [O. M.], Taphorn [D. C.], Lasso [C. A.] & León-Mata [O.] 2006:23, Figs. 1-3 [Zootaxa No. 1275; ref. 28774] Small stream, a tributary entering right side of Ichún River, downstream from Ichún, on Espuma Falls, tributary of Paragua River, Caroni River system, Orinoco River basin, Bolivar State, Venezuela., about 4°46'04N, 63°27'57"W, elevation 340 meters. Holotype: MHNLS 18934. Paratypes: ANSP 182913 (4); MCNG 54730 (4), 54731 (7); MBVCV-V-32971 (3); MHNLS 18935 (4), 18936 (6), 18937 (1) •Valid as Rivulus sape Lasso-Alcalá, Taphorn, Lasso & León-Mata 2006. •Valid as Laimosemion sape (Lasso-Alcalá, Taphorn, Lasso & León-Mata 2006) -- (Costa 2011:240 [ref. 31655], Costa & Lazzarotto 2014:372 [ref. 33247]). Current status: Valid as Laimosemion sape (Lasso-Alcalá, Taphorn, Lasso & León-Mata 2006). Rivulidae: Rivulinae. Distribution: Paragua River system of upper Caroni River drainage, Orinoco River basin, Venezuela. Habitat: freshwater.

scalaris, Rivulus Costa [W. J. E. M.] 2005:78, Fig. 10 [Neotropical Ichthyology v. 3 (no. 1); ref. 28192] Município de Costa Rica, stream tributary to the upper rio Sucuruí drainage, rio Paraná basin, 18°53'54.7"S, 52°58'44.2"W, Estado de Mato Grosso do Sul, Brazil, elevation 810 meters. Holotype: UFRJ 5968. Paratypes: MCP 36125 (5); UFRJ 2277 (5), 2278 (4, c&s), 5969 (19), 5970 (4). •Valid as Rivulus scalaris Costa 2005 -- (Costa 2006:162 [ref. 28875] in subgenus Melanorivulus, Costa 2008:86 [ref. 29717]). •Valid as Melanorivulus scalaris (Costa 2005) -- (Costa 2011:241 [ref. 31655], Nielsen et al. 2016:87 [ref. 34407], Volcan et al. 2017:92 [ref. 35156], Deprá et al. 2017:121 [ref. 35503], Costa 2018:25 [ref. 35717], Volcan et al. 2018:275 [ref. 35895]). Current status: Valid as Melanorivulus scalaris (Costa 2005). Rivulidae: Rivulinae. Distribution: Paraná River and upper Paraguay river basins, Brazil. Habitat: freshwater.

schindleri, Pituna Costa [W. J. E. M.] 2007:13, Figs. 8-9 [Zootaxa No. 1410; ref. 28993] Road BR-343, 26 kilometers northwest from Camp Maior, rio Corrente drainage, rio Parnaíba basin, about 4°30'S, 42°00'W, Estado do Piauí, Brazil. Holotype: UFRJ 6399. Paratypes: MCP 40497 (6); UFRJ 4592 (6), 4879 (46), 5547 (8, c&s), 5548 (1) •Valid as Pituna schindleri Costa 2007 -- (Ramos et al. 2014:4 [ref. 35321]). Current status: Valid as Pituna schindleri Costa 2007. Rivulidae: Rivulinae. Distribution: Seasonal pools in lower Parnaíba River basin, northeastern Brazil. Habitat: freshwater.

schleseri, Aphyolebias Costa [W. J. E. M.] 2003:160, Fig. 2B [Comunicações do Museu de Ciências e Tecnologia da PUCRS, Sér. Zoologia. v. 16 (no. 2); ref. 27616] About 1 kilometer upriver from Tacshacuraray, about 3°50'S, 72°30'W, caño Lata, drainage of río Orosa, tributary of Amazon River, Depart Loreto, Peru. Holotype: MUSM 20294. Paratypes: UFRJ 5471(2), 5472 (2, c&s). •Valid as Aphyolebias schleseri Costa 2003. •Valid as Moema schleseri (Costa 2003) -- (Valdesalici et al. 2015:129 [ref. 33902], Meza-Vargas et al. 2021:27 [ref. 39298]). Current status: Valid as Moema schleseri Costa 2003. Rivulidae: Rivulinae. Distribution: South America: Amazon basin (Peru). Habitat: freshwater.

schreitmuelleri, Cynolebias Ahl [E.] in Schreitmüller 1934:673, Fig. 1 [Wochenschrift für Aquarien- und Terrarienkunde v. 31 (no. 43); ref. 35925] Laguna dos Patos system, Rio Grande do Sul, Brazil. Neotype: UFRJ 6218. Later described, as Cynolebias schreitmülleri, by Ahl 1934: 308 [ref. 16410]. No types at ZMB: Paepke & Seegers 1986:157 [ref. 19981], Paepke 1995:94 [ref. 21847]; 3 syntypes lost. Neotype designated by Costa 2006:48 [ref. 28708]. •Regarded as a nomen dubium, incertae sedis -- (Costa 2001:347 [ref. 25719]). •Synonym of Austrolebias wolterstorffi (Ahl 1924) -- (Costa 2006:48 [ref. 28708], Lanés et al. 2014:17 [ref. 33234], Litz & Koerber 2014:31 [ref. 33622]). •Synonym of Megalebias wolterstorffi (Ahl 1924) -- (Lazara 2001:204 [ref. 25711]). Current status: Synonym of Megalebias wolterstorffi (Ahl 1924). Rivulidae: Cynolebiinae. Habitat: freshwater.

schuncki, Rivulus Costa [W. J. E. M.] & De Luca [A. C.] 2011:290, Fig. 1 [Ichthyological Exploration of Freshwaters v. 21 (no. 4) [Dec. 2010]; ref. 31185] Stream near Vila Nova, road AP 030, Anauerapucu River basin, Amazonas River basin, 0°08'23"N, 51°32'14"W, Estado do Amapá, Brazil. Holotype: UFRJ 6766. Paratypes: UFRJ 6767 (4), 6768 (6, c&s). •Valid as Melanorivulus schuncki (Costa & De Luca 2011) -- (Costa 2011:241 [ref. 31655], Bragança et al. 2012:51 [ref. 32067], Melo et al. 2016:135 [ref. 34701], Costa et al. 2016:270 [ref. 35405]). Current status: Valid as Melanorivulus schuncki (Costa & De Luca 2011). Rivulidae: Rivulinae. Distribution: Amazon River basin, Brazil. Habitat: freshwater.

semiocellatus, Spectrolebias Costa [W. J. E. M.] & Nielsen [D. T. B.] 1997:259, Figs. 1-2 [Ichthyological Exploration of Freshwaters v. 7 (no. 3); ref. 22744] Rio Araguaia Basin, Brazil. Holotype: MZUSP 50654. Paratypes: MZUSP 50655 (3); UFRJ 3632 (6), 3633 (5, c&s). •Valid as Simpsonichthys semiocellatus (Costa & Nielsen 1997) -- (Costa 2006:17 [ref. 28620], Costa 2007:52 [ref. 29445], Costa & Brasil 2008:245 [ref. 29968]). •Valid as Spectrolebias semiocellatus Costa & Nielsen 1997 -- (Costa 1998:74 [ref. 23792], Costa & Le Bail 1999:1028 [ref. 24187], Lazara 2001:301 [ref. 25711], Costa et al. 2003:144 [ref. 26946], Costa in Reis et al. 2003:542 [ref. 27061], Nielsen 2013:81 [ref. 32696], Niesen & Brousseau 2013:116 [ref. 32794], Costa & Amorim 2018:365 [ref. 36019]). Current status: Valid as Spectrolebias semiocellatus Costa & Nielsen 1997. Rivulidae: Cynolebiinae. Distribution: Araguaia River basin, central Brazil. Habitat: freshwater.

sepia, Kryptolebias Vermeulen [F. B. M.] & Hrbek [T.] 2005:4, Figs. 1-7 [Zootaxa No. 928; ref. 28142] 5 kilometers downriver from Palumeu on the right bank, 3°22'43"N, 55°24'42"W, Tapanahony River, Upper Marowijne system, Suriname. Holotype: ZMA 123714. Paratypes: MNHN 2004-3096 (1); NYCZ F6418 (1), F7063-66 (4); ZMA 123715 (1, allotype), 123716 (2), 123717 (6). •Valid as Kryptolebias sepia Vermeulen & Hrbek 2005 -- (Vermeulen 2022:14 [ref. 39817]). Current status: Valid as Kryptolebias sepia Vermeulen & Hrbek 2005. Rivulidae: Kryptolebiatinae. Distribution: South America: Tapanahony and Palumeu River drainages, southeastern Suriname. Habitat: freshwater.

sertanejo, Hypsolebias Costa [W. J. E. M.] in Costa, Amorim & Mattos 2012:85, Figs. 9, 15 [Systematics and Biodiversity v. 10 (no. 1); ref. 31845] Seasonal pool east of town of Januária, São Francisco River floodplains, 15°30'01"S, 44°23'18"W, Estado de Minas Gerais, Brazil, elevation 450 meters. Holotype: UFRJ 8380. Paratypes: BMNH 2011.11.17.12-15 (4), plus many at UFRJ. Plus additional non-type material. •Valid as Hypsolebias sertanejo Costa 2012 -- (Costa et al. 2013:1 [ref. 32952], Britzke et al. 2016:134 [ref. 34461]). Current status: Valid as Hypsolebias sertanejo Costa 2012. Rivulidae: Cynolebiinae. Distribution: Upper part of middle São River basin, Minas Gerais, Brazil. Habitat: freshwater.

shibattai, Hypsolebias Nielsen [D. T. B.], Martins [M.], Araujo [L. M. de] & Suzart [R. dos R.] 2014:2, Figs. 1-2 [aqua, International Journal of Ichthyology v. 20 (no. 1); ref. 33143] Bahia, Bom Jesus da Lapa, rio São Fancisco basin, temporary pool at road BR-430, 13°21'16"S, 43°17'15"W, Brazil, elevation 433 meters. Holotype: ZUEC 7648. Paratypes: MZUEL 7879 (4), ZUEC 7649 (6). •Valid as Hypsolebias shibattai Nielsen, Martins, Araujo & Suzart 2014 -- (Silva et al. 2020:14 [ref. 37809]). Current status: Valid as Hypsolebias shibattai Nielsen, Martins, Araujo & Suzart 2014. Rivulidae: Cynolebiinae. Distribution: South America: Bon Jesus de Lapa (Bahia State, Brazil). Habitat: freshwater.

sicheleri, Cynopoecilus Miranda Ribeiro [A. de] 1939:363 [Boletim Biológico, São Paulo (Nova Série) v. 4 (no. 3); ref. 3023] Base of the Serra de Petrópolis, Rio de Janeiro State, Brazil. Syntypes: MNRJ 4739 (8). Type catalog: Miranda Ribeiro 1955:398 [ref. 12732] as sichcleri on p. 391. Also misprinted ticheleri (see Huber 2006:11 [ref. 28935]). •Synonym of Leptolebias marmoratus (Ladiges 1934) -- (Costa 1995:92 [ref. 22097], Lazara 2001:193 [ref. 25711], Costa 2002:380 [ref. 26544], Costa in Reis et al. 2003:530 [ref. 27061], Costa 2008:156 [ref. 29596]). Current status: Synonym of Leptolebias marmoratus (Ladiges 1934). Rivulidae: Cynolebiinae. Habitat: freshwater.

siegfriedi, Rivulus uroflammeus Bussing [W. A.] 1980:340, Figs. 2C, 5C, 6C [Brenesia No. 17; ref. 8732] Stream tributary to Río Térraba, 3.6 kilometers south of Palmar Norte, Puntarenas Province, Costa Rica, elevation 20 meters. Holotype: LACM 38274-1. Paratypes: LACM 38274-2 (5); UCR 111-16 (8), 112-20 (1), 1195-1 (1), 1196-1 (2), 1197-1 (4). Type catalog: Angulo et al. 2015:373 [ref. 35212]. •Doubtfully valid as Rivulus uroflammeus Bussing 1980, subspecies siegfriedi Bussing 1980 -- (Huber 1992:400 [ref. 20639]). •Synonym of Rivulus uroflammeus Bussing 1980, but a valid subspecies as described -- (Bussing 1998:179 [ref. 24179], Lazara 2001:285 [ref. 25711]). •Valid as Rivulus siegfriedi Bussing 1980 -- (Costa in Reis et al. 2003:539 [ref. 27061], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys). •Valid as Cynodonichthys siegfriedi (Bussing 1980) -- (Costa 2011:242 [ref. 31655], Angulo et al. 2013:995 [ref. 33194]). Current status: Valid as Cynodonichthys siegfriedi (Bussing 1980). Rivulidae: Rivulinae. Distribution: Pacific river basins, Costa Rica. Habitat: freshwater.

similis, Simpsonichthys Costa [W. J. E. M.] & Hellner [S.] 1999:90, Fig. 1 [Revue française d'Aquariologie Herpétologie v. 25 (no. 3/4) [for 1998]; ref. 23864] Temporary pool close to Urucuia, road to São Romão, rio Urucuia basins, Estado de Minas Gerais, Brazil [ca. 16°05'S, 454°45'W, elevation about 500 m]. Holotype: MZUSP 51834. Paratypes: MZUSP 51835 (1); UFRJ 4146 (1), 4147 (5, c&s), 4148 (1). •Valid as Simpsoichthys similis Costa & Hellner 1999 -- (Lazara 2001:298 [ref. 25711], Costa in Reis et al. 2003:542 [ref. 27061], Costa & Brasil 2004:2 [ref. 28012], Costa 2005:63 [ref. 28575], Costa 2006:17 [ref. 28620], Costa 2007:70 [ref. 29445]). •Valid as Hypsolebias similis (Costa & Hellner 1999) -- (based on generic placement in Costa 2011 [ref. 31654]). Current status: Valid as Hypsolebias similis (Costa & Hellner 1999). Rivulidae: Cynolebiinae. Distribution: São Francisco River basin, Brazil. Habitat: freshwater.

simplicis, Rivulus Costa [W. J. E. M.] 2004:104, Figs. 1-2 [aqua, Journal of Ichthyology and Aquatic Biology v. 8 (no. 3); ref. 27824] Swamp near Jabaquara beach, 23°12'26.7"S, 44°43'12.9"W, Parati, Estado do Rio de Janeiro, Brazil, elevation 23 meters. Holotype: UFRJ 5940. Paratypes: UFRJ 5941 (31), 5942 (5, c&s), 5976 (3). •Valid as Rivulus simplicis Costa 2004 -- (Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys, Costa 2007:127 [ref. 29225], Costa 2008:47 [ref. 29622] in subgenus Atlantirivulus, Costa 2008:135 [ref. 29871]). •Valid as Atlantirivulus simplicis (Costa 2004) -- (Costa 2011:244 [ref. 31655]). Current status: Valid as Atlantirivulus simplicis (Costa 2004). Rivulidae: Rivulinae. Distribution: Coastal plains of southeastern Brazil. Habitat: freshwater.

sladkowskii, Rivulus Vermeulen [F. B. M.] 2023:103, Figs. 1-6 [Killi-Data Series 2023; ref. 40177] Small creek, about 14.6 km southeast of the indigenous village Mitú, Vaupés Department, eastern Colombia, 1°9'57.12"N, 70°8'54.18"W, elevation 190 meters. Holotype: CIUA 0008005. Paratypes: CIUA 0008006 (9), 0008007 (2). Genus tentative. •Valid as Laimosemion sladkowskii (Vermeulen 2023). Current status: Valid as Laimosemion sladkowskii (Vermeulen 2023). Rivulidae: Rivulinae. Distribution: South America: upper Vaupés River drainage, Vaupés Department, eastern Colombia. Habitat: freshwater.

speciosus, Rivulus Fels [J. F.] & de Rham [P.] 1981:66, Fig. [Revue française d'Aquariologie Herpétologie v. 8 (no. 3); ref. 8607] Quisto Cocha, 3°56'S, 72°24'W, 18 kilometers from Iquitos on Iquitos-Nauta Road, Peru. Holotype: MHNG 2079.68. Paratypes: MHNG 2079.69 to .76 (8), MNHN 1981-1271 (3). Type catalog: Weber 1998:12 [ref. 32707]. •Valid as Rivulus speciosus Fels & de Rham 1981 -- (Ortega & Vari 1986:19 [ref. 9708], Huber 1992:403 [ref. 20639], Lazara 2001:284 [ref. 25711], Costa in Reis et al. 2003:539 [ref. 27061], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys, Huber 2021:9 [ref. 38709]). •Valid as Anablepsoides speciosus (Fels & de Rham 1981) -- (Costa 2011:243 [ref. 31655], Meza-Vargas et al. 2021:27 [ref. 39298]). Current status: Valid as Anablepsoides speciosus (Fels & de Rham 1981). Rivulidae: Rivulinae. Distribution: South America: middle Amazon River basin (Peru). Habitat: freshwater.

spinifer, Cynolebias Ahl [E.] 1934:310 [Zoologischer Anzeiger v. 108 (nos 11/12); ref. 16410] La Plata, Buenos Aires, Argentina. Lectotype: ZMH H64. Paralectotypes: ZMB 21164 (2), ZMH H38 (2). Type catalog: Ladiges et al. 1958:161 [ref. 19181], Paepke & Seegers 1986:157 [ref. 19981], Wilkens & Dohse 1993:404 [ref. 21161] with syntypes. Types mentioned: Paepke 1995:94 [ref. 21847] as spinnifer. •Synonym of Cynolebias elongatus Steindachner 1881 -- (Costa 1995:78 [ref. 22097]). •Synonym of Megalebias elongatus (Steindachner 1881) -- (Lazara 2001:203 [ref. 25711], Costa in Reis et al. 2003:531 [ref. 27061]). •Synonym of Austrolebias elongatus (Steindachner 1881) -- (Costa 2006:57 [ref. 28708], Litz & Koerber 2014:30 [ref. 33622], Mirande & Koerber 2015:51 [ref. 35117]). •Synonym of Titanolebias elongatus (Steindachner 1881). Current status: Synonym of Titanolebias elongatus (Steindachner 1881). Rivulidae: Cynolebiinae. Habitat: freshwater.

spixi, Melanorivulus Costa [W. J. E. M.] 2016:132, Fig. 20 [Ichthyological Exploration of Freshwaters v. 27 (no. 2) for Oct.; ref. 34900] Swamp close to road MT-240, 7 km east of Água Boa, between Água Boa and road MT-100, Município de Água Boa, Mato Grosso, Brazil, 14°01'00"S, 52°05'48"W, elevation about 480 meters. Holotype: UFRJ 6869. Paratypes: UFRJ. Plus additional non-type material. •Valid as Melanorivulus spixi Costa 2016 -- (Nielsen 2017:66 [ref. 35340], Nielsen & Britzke 2019:41 [ref. 36525]). Current status: Valid as Melanorivulus spixi Costa 2016. Rivulidae: Rivulinae. Distribution: Rio Araguaia drainage, Brazil. Habitat: freshwater.

splendens, Cynolebias Myers [G. S.] 1942:110 [Stanford Ichthyological Bulletin v. 2 (no. 4); ref. 3121] Water holes or ponds along base of Serra de Petrópolis, Rio de Janeiro State, Brazil. Holotype: CAS-SU 36527. Paratypes: CAS-SU 36528 (3). Type catalog: Type catalog: Böhlke 1953:53 [ref. 12291]. Conserved over senior subjective synonym Cynopoecilus [as Gynopoecilus] sandrii Faria & Muller 1937 (Case 2792) and placed on Official List (Opinion 1762). •Synonym of Cynolebias sandrii (Faria & Muller 1937) -- (Costa & Lacerda 1988:129 [ref. 19183], Costa 1995:94 [ref. 22097]). •Valid as Leptolebias splendens (Myers 1942) -- (Lazara 2001:195 [ref. 25711], Costa 2002:383 [ref. 26544], Costa in Reis et al. 2003:531 [ref. 27061], Costa 2008:155 [ref. 29596], Ferrer et al. 2014:847 [ref. 33589]). •Valid as Leptopanchax splendens (Myers 1942) -- (Costa 2016:128 [ref. 34776], Costa 2019:82 [ref. 36869]). Current status: Valid as Leptopanchax splendens (Myers 1942). Rivulidae: Cynolebiinae. Distribution: Atlantic coastal river basins, Rio de Janeiro State, Brazil. Habitat: freshwater.

splendens, Rachovia Dahl [G.] 1958:43 [Stanford Ichthyological Bulletin v. 7 (no. 3); ref. 12064] Semi-permanent pond at Sincelejo, northern Colombia. Holotype: Retained by Dahl. Paratypes: (several hundred, plus allotype) CAS-SU 49519 (orig. 16, now 11), CAS-SU 68749 (1, c&s). Appeared first in Dahl 1958:34 [ref. 19187] if date of 18 June is correct for ref. 19187. •Synonym of Rachovia brevis (Regan 1912) -- (Taphorn & Thomerson 1978:389 [ref. 4337], Lazara 2001:265 [ref. 25711], Costa in Reis et al. 2003:533 [ref. 27061]). •Valid as Rachovia splendens Dahl 1958 -- (Berkenkamp 2020:15 [ref. 37695]). Current status: Valid as Rachovia splendens Dahl 1958. Rivulidae: Rivulinae. Distribution: Río Sinu basin, northern Colombia. Habitat: freshwater.

splendida, Maratecoara Costa [W. J. E. M.] 2007:36, Figs. 27-28 [Zootaxa No. 1410; ref. 28993] Temporary lagoon pool in left rio Canabrava floodplains, rio Santa Tereza drainage, rio Tocantins basin, road TO-373, between Alvorada and Peixe, 12°29'46.3"S, 49°00'50.7"W, Estado do Tocantins, Brazil, elevation 292 meters. Holotype: UFRJ 6431. Paratypes: MCP 40501 (2); UFRJ 6432 (9), 6433 (4). •Valid as Maratecoara splendida Costa 2007. Current status: Valid as Maratecoara splendida Costa 2007. Rivulidae: Rivulinae. Distribution: Brazil. Habitat: freshwater.

splendidus, Neofundulus Nielsen [D. T. B.] & Brousseau [R.] 2013:110, Figs. 1-2 [aqua, International Journal of Ichthyology v. 19 (no. 3); ref. 32795] Departamento Santa Cruz, San Miguel city, río San Miguel, río Mamoré basin, Bolivia,16°46’22.0°S, 61°11’12.6°W, altitude 440 meters. Holotype: MNKP 11205. Paratypes: MNKP 11206 (11), ZUEC 7303 (2). •Valid as Neofundulus splendidus Nielsen & Brousseau 2013 -- (Sarmiento et al. 2014:187 [ref. 35004], Costa 2015:15 [ref. 33783], Drawert 2023:37 [ref. 40730]). Current status: Valid as Neofundulus splendidus Nielsen & Brousseau 2013. Rivulidae: Rivulinae. Distribution: South America: Río Mamoré basin (Bolivia). Habitat: freshwater.

splendissimus, Hypsolebias Costa [W. J. E. M.] in Costa, Amorim & Mattos 2018:498, Figs. 2-3 [Zoosystematics and Evolution v. 94 (no. 2); ref. 36319] Temporary pool close to road BR-030, about 1.5 km W from the confluence between the Poço do Magro River and the Carnaíba de Dentro River, São Francisco River basin, Guanambi, Bahia, Brazil, 14°12'54"S, 42°50'22"W, elevation about 505 meters. Holotype: UFRJ 6909. Paratypes: UFRJ. •Valid as Hypsolebias splendissimus Costa 2018. Current status: Valid as Hypsolebias splendissimus Costa 2018. Rivulidae: Cynolebiinae. Distribution: Middle São Francisco River basin, Bahia, Brazil. Habitat: freshwater.

staecki, Pterolebias Seegers [L.] 1987:202, Figs. (p. 199, 201) [Die Aquarien- und Terrarienzeitschrift (DATZ) v. 40 (no. 5); ref. 9161] Lagune des Lago Janauacá, 3°25'S, 60°16'W, southwest of Manaus, Brazil. Holotype: ZFMK 14597. Paratypes: MZUSP (2), ZFMK 14598-01 (4). Type catalog: Herder et al. 2010:125 [ref. 31087]. •Valid as Moema staecki (Seegers 1987) -- (Costa 1993:623 [ref. 21979], Costa 1998:79 [ref. 23792], Lazara 2001:211 [ref. 25711], Costa in Reis et al. 2003:532 [ref. 27061], Huber 2003:14 [ref. 27251], Costa 2003:173 [ref. 27617], Valdesalici et al. 2015:129 [ref. 33902], Valdesalici 2016:66 [ref. 34174]). Current status: Valid as Moema staecki (Seegers 1987). Rivulidae: Rivulinae. Distribution: Lower River Negro and Solimões floodplains, Amazon River basin, Brazil. Habitat: freshwater.

staecki, Rivulus Schindler [I.] & Valdesalici [S.] 2011:111, Figs. 1-5 [Vertebrate Zoology v. 61 (no. 1); ref. 31382] Rio Negro drainage, pond close to village Arigua [Darigua on p. 112], about 20 km south of San Carlos de Rio Negro, ca. 1°50'N, 67°02'W, Estado Amazonas, Venezuela. Holotype: MCNG-UNELLEZ 56350. Paratypes: MCNG-UNELLEZ 56351 (1); MTD F 32344-32348 and 32397-32400 (9), plus author collection (1, c&s). •Valid as Rivulus staecki Schindler & Valdesalici 2011 -- (Vermeulen et al. 2013:191 [ref. 32954], Vermeulen & Mejia-Vargas 2020:34 [ref. 37938]). •Valid as Laimosemion staecki (Schlinder & Valdesalici 2011) -- (Costa & Lazzarotto 2014:372 [ref. 33247]). Current status: Valid as Laimosemion staecki (Schindler & Valdesalici 2011). Rivulidae: Rivulinae. Distribution: Rio Negro Basin, Amazonas, Venezuela and Colombia. Habitat: freshwater.

stagnalis, Austrofundulus Schultz [L. P.] 1949:88, Fig. 11 [Proceedings of the United States National Museum v. 99 (no. 3235); ref. 3967] About 6 kilometers north of Río Misoa and 20 kilometers south of Lagunillas, Maracaibo basin, Venezuela. Holotype: UMMZ 141918. Paratypes: UMMZ 141919 (103, now 81, 16 c&s), 141933 [ex USNM 121691] (15), ?200210 (9); USNM 121691 (orig. 125), 122006 (10); ZMA 102130 (5). Type catalog: Nijssen et al. 1982:69 [ref. 19236]. •Synonym of Austrofundulus limnaeus Schultz 1949 -- (Taphorn & Thomerson 1978:414 [ref. 4337], Lazara 2001:57 [ref. 25711], Costa in Reis et al. 2003:527 [ref. 27061], Hrbek et al. 2005:22 [ref. 28063]). Current status: Synonym of Austrofundulus limnaeus Schultz 1949. Rivulidae: Rivulinae. Habitat: freshwater.

stagnatus, Rivulus Eigenmann [C. H.] 1909:50 [Annals of the Carnegie Museum v. 6 (no. 1); ref. 1222] Christianburg, Guyana. Holotype: FMNH 52715 [ex CM 1082]. Paratypes: (19, CM and IU) BMNH 1911.10.31.536 (2); CAS 44228 [ex IU 11761] (3), 44228 (1, dessicated, not found); FMNH 7558 (1), 52716 (4); MCZ 29990 (1); NMW 83154 (1); CAS-SU 21971 (1); USNM 66303 (1); ZMB 18100 (1). Type catalog: Henn 1928:86 [ref. 12305], Böhlke 1953:54 [ref. 12291], Paepke & Seegers 1986:169 [ref. 19981], Ibarra & Stewart 1987:76 [ref. 12367]. •Valid as Rivulus stagnatus Eigenmann 1909 -- (Huber 1992:406 [ref. 20639], Murphy & Collier 1997:797 [ref. 25585], Lazara 2001:284 [ref. 25711], Costa in Reis et al. 2003:539 [ref. 27061], Suijker & Collier 2006:2 [ref. 28729], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys, Costa 2010:84 [ref. 30788], Vermeulen 2022:13 [ref. 39817]). •Valid as Anablepsoides stagnatus (Eigenmann 1909) -- (Costa 2011:243 [ref. 31655], Costa et al. 2013:292 [ref. 33108], Nielsen 2016:166 [ref. 34861], Taphorn et al. 2022:36 [ref. 41297]). Current status: Valid as Anablepsoides stagnatus (Eigenmann 1909). Rivulidae: Rivulinae. Distribution: South America: Atlantic coastal river basins (Guyana and Suriname). Habitat: freshwater.

stellatus, Cynolebias Costa [W. J. E. M.] & Brasil [G. C.] 1994:5, Fig. 1 [Revue française d'Aquariologie Herpétologie v. 21 (no. 1/2); ref. 21598] Temporary pool, 1 kilometer north of São Francisco, Minas Gerais State, Brazil. Holotype: MNRJ 12446. Paratypes: MNRJ 12518 (3); MZUSP 45771 (4); UFRJ 2066 (5), 2067 (4, 3 c&s). •Valid as Simpsonichthys stellatus (Costa & Brasil 1994) -- (Costa 1996:130 [ref. 25271], Costa 1998:75 [ref. 23792], Lazara 2001:298 [ref. 25711], Costa in Reis et al. 2003:542 [ref. 27061], Costa & Brasil 2004:2 [ref. 28012], Costa 2005:63 [ref. 28575], Costa 2006:17 [ref. 28620], Costa 2007:61 [ref. 29445]). •Valid as Hypsolebias stellatus (Costa & Brasil 1994) -- (based on generic placement in Costa 2011 [ref. 31654]). Current status: Valid as Hypsolebias stellatus (Costa & Brasil 1994). Rivulidae: Cynolebiinae. Distribution: Middle São Francisco River floodplains, Minas Gerais State, Brazil. Habitat: freshwater.

stellifer, Rivulus Thomerson [J. E.] & Turner [B. J.] 1973:783, Figs. 1-2 [Copeia 1973 (no. 4); ref. 35] Temporary pond, about 1 kilometer north of Caño Benito, Estado Cojedes, on road between E. Pao and El Baul, Cojedes, Venezuela, 9°16'N, 68°09'W. Holotype: USNM 209254. Paratypes: CAS 27556 (2), FMNH 71667-68 (4, 1), ICNMNH 700 (3), MBUCV-V-7199 (4), UMMZ 193375 (2), USNM 209255 (now 3). Type catalog: Ibarra & Stewart 1987:76 [ref. 12367] as 5 paratypes at FMNH, Provenzano et al. 1998:17 [ref. 24196], Mojica & Agudelo-Zamora 2018:52 [ref. 36127]. •Valid as Rivulus stellifer Thomerson & Turner 1973 -- (Huber 1992:410 [ref. 20639]). •Valid as Pituna stellifer (Thomerson & Turner 1973) -- (Costa 1991:331 [ref. 20644]). •Valid as Rachovia stellifer (Thomerson & Turner 1973) -- (Costa 1998:80 [ref. 23792], Lazara 2001:266 [ref. 25711], Costa in Reis et al. 2003:534 [ref. 27061], Radda 2004:21 [ref. 27638]). •Valid as Llanolebias stellifer (Thomerson & Turner 1973) -- (Hrbek & Taphorn 2008 [ref. 29747], Reis et al. 2016:13 [ref. 34496]). Current status: Valid as Llanolebias stellifer (Thomerson & Turner 1973). Rivulidae: Rivulinae. Distribution: Orinoco River basin, Venezuela. Habitat: freshwater.

strigabundus, Trigonectes Myers [G. S.] 1925:371 [The Fish Culturist v. 4 (no. 8); ref. 5744] Porto Nacional, Rio Tocantins, Goiaz, Brazil. Holotype: CAS 40701 [ex IU uncat.]. Paratypes: CAS 40702 [ex IU uncat.] (4). Appeared in more detail in Myers 1927:128 [ref. 3098]. •Valid as Trigonectes strigabundus Myers 1925 -- (Costa 1990:148 [ref. 14542], Costa 1998:78 [ref. 23792], Lazara 2001:310 [ref. 25711], Costa in Reis et al. 2003:543 [ref. 27061]). Current status: Valid as Trigonectes strigabundus Myers 1925. Rivulidae: Rivulinae. Distribution: Tocantins River basin, Brazil. Habitat: freshwater.

strigatus, Rivulus Regan [C. T.] 1912:502 [Annals and Magazine of Natural History (Series 8) v. 10 (no. 59); ref. 3648] Amazon River basin [Rio de Prata, tributary of rio Jari, Pará]. Holotype (unique): BMNH 1912.8.30.5. Combined with a neuter genus, the adjective should be strigatum. •Synonym of Rivulus geayi Vaillant 1899 -- (Huber 1991:70 [ref. 19721], Huber 1992 [ref. 20639], Fernández & Butí 1996:255 [ref. 22775], Huber 1999:50 [ref. 23834], Lazara 2001:275 [ref. 25711], Hrbek et al. 2004:569 [ref. 27910]). •Valid as Rivulus strigatus Regan 1912 -- (Costa in Reis et al. 2003:539 [ref. 27061], Costa 2006:153 [ref. 28875] in subgenus Laimosemion). •Valid as Laimosemion strigatum (Regan 1912) -- (Costa 2011:240 [ref. 31655] as strigatus, Vermeulen et al. 2012:188 [ref. 32253] as strigatus, Valdesalici & García Gil 2015:169 [ref. 34010] as strigatus). Current status: Valid as Laimosemion strigatum (Regan 1912). Rivulidae: Rivulinae. Distribution: Lower Amazon River basin, Brazil. Habitat: freshwater.

sucubti, Rivulus chucunaque Breder [C. M., Jr.] 1925:8, Fig. 7 [American Museum Novitates No. 180; ref. 15531] Río Sucubti, in a small side stream, Darien Province, Panama. Holotype: AMNH 8407. Paratypes: (45) AMNH 22731-32 (21, 7); USNM 94227 (10). Type catalog: Huber 1992 [ref. 20639]. •Probable synonym of Rivulus chucunaque Breder 1925 -- (Huber 1992:418 [ref. 20639]). •Synonym of Rivulus chucunaque Breder 1925, but a valid subspecies as described -- (Lazara 2001:272 [ref. 25711], Etzel & Berkenkamp 1992:30 [ref. 32437]). •Synonym of Rivulus chucunaque Breder 1925 -- (Costa in Reis et al. 2003:535 [ref. 27061]). •Valid as Rivulus sucubti Breder 1925 -- (Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys). •Valid as Cynodonichthys sucubti (Breder 1925) -- (Costa 2011:242 [ref. 31655]). •Synonym of Cynodonichthys chucunaque (Breder 1925). Current status: Synonym of Cynodonichthys chucunaque (Breder 1925). Rivulidae: Rivulinae. Habitat: freshwater.

suzarti, Simpsonichthys Costa [W. J. E. M.] 2004:2, Figs. 1-2 [Zootaxa No. 468; ref. 27569] Temporary pool near Canavieiras, rio Pardo floodplains, about 15°45'S, 39°00'W, northeastern Brazil, elevation about 4 meters. Holotype: MCP 34088. Paratypes: UFRJ 5810 (1), 5811 (2, 1 c&s). •Valid as Simpsonichthys suzarti Costa 2004 -- (Costa 2007:18 [ref. 29445], Costa & Lima 2010:205 [ref. 31041] in subgenus Ophthalmolebias). •Valid as Ophthalmolebias suzarti (Costa 2004) -- (Silva et al. 2020:15 [ref. 37809], Vieira-Guimarães et al. 2024:55 [ref. 41258]). Current status: Valid as Ophthalmolebias suzarti (Costa 2004). Rivulidae: Cynolebiinae. Distribution: South America: Rio Pardo floodplains, Bahia State (Brazil). Habitat: freshwater.

taeniatus, Rivulus Fowler [H. W.] 1945:129, Figs. 44-45 [Proceedings of the Academy of Natural Sciences of Philadelphia v. 97; ref. 1454] Río Caquetá drainage, Morelia, Colombia [probably Bodoquero River, near the town of Morelia]. Holotype: ANSP 71720. Paratypes: ANSP 71721 (1, bisected). Type catalog: Böhlke 1984:97 [ref. 13621]. •Status uncertain -- (Huber 1992:421 [ref. 20639]). •Valid as Rivulus taeniatus Fowler 1945 -- (Lazara 2001:284 [ref. 25711], Costa in Reis et al. 2003:539 [ref. 27061], Costa 2006:139, 143, 165 [ref. 28875] in subgenus Cynodonichthys, Valdesalici & Schindler 2011:313 [ref. 31673] in subgenus Cynodonichthys). •Valid as Anablepsoides taeniatus (Fowler 1945) -- (Costa 2011:243 [ref. 31655], Costa 2013:346 [ref. 32528], Valdesalici & Schindler 2013:296 [ref. 33109], Nielsen et al. 2016:77 [ref. 34406], Nielsen 2016:166 [ref. 34861], DoNascimiento et al. 2017:101 [ref. 35633], Valdesalici & Gil 2019:152 [ref. 37074], Nielsen et al. 2022:35 [ref. 39105]). Current status: Valid as Anablepsoides taeniatus (Fowler 1945). Rivulidae: Rivulinae. Distribution: Upper Amazon basin, Colombia. Habitat: freshwater.

tecminae, Rivulus Thomerson [J. E.], Nico [L. G.] & Taphorn [D. C.] 1992:290, Figs. 1-3 [Ichthyological Exploration of Freshwaters v. 2 (no. 4); ref. 14220] Open savanna pools about 500 meters from left bank, Río Guayapo, Río Orinoco basin, Venezuela, 4°16'N, 67°20'W. Holotype: MCNB 23886. Paratypes: FMNH 100599 (4); MBUCV-V-20344 (4); MCNG 21363-64 (9, 46), 21368-69 (7, 33), 21372 (20), 21375 (7), 21844 (1), 23887 (1), 23899 (6), 23905 (2), 23907 (1), 23909 (2), 23190 (12); MAC-PAY 1155 (13). Type catalog: Provenzano et al. 1998:17 [ref. 24196]. •Valid as Rivulus tecminae Thomerson, Nico & Taphorn 1992 -- (Huber 1992:425 [ref. 20639], Lazara 2001:284 [ref. 25711], Costa 2004:4 [ref. 27570], Radda 2004:21 [ref. 27638], Costa 2004:11 [ref. 27656], Hrbek et al. 2004:573 [ref. 27910], Costa 2004:2 [ref. 27923], Costa 2006:157, 160 [ref. 28875] in subgenus Owiyeye, Schindler & Valdesalici 2011:109 [ref. 31382], Vermeulen et al. 2013:191 [ref. 32954], Vermeulen & Mejia-Vargas 2020:19 [ref. 37935], Vermeulen & Mejia-Vargas 2020:33 [ref. 37938]). •Valid as Laimosemion tecminae (Thomerson, Nico & Taphorn 1992) -- (Costa 2011:240 [ref. 31655], Costa & Lazzarotto 2014:372 [ref. 33247]). Current status: Valid as Laimosemion tecminae (Thomerson, Nico & Taphorn 1992). Rivulidae: Rivulinae. Distribution: Orinoco River basin, Venezuela and upper Negro River basin, Brazil and Colombia. Habitat: freshwater.

tenuis, Cynodonichthys Meek [S. E.] 1904:101, Fig. 27 [Field Columbian Museum, Zoölogical Series v. 5; ref. 2958] El Hule, Oaxaca, Mexico. Holotype (unique): FMNH 4643. Type catalog: Ibarra & Stewart 1987:30 [ref. 12367]. •Valid as Cynodonichthys tenuis Meek 1904 -- (Costa 2011:242 [ref. 31655]). •Valid as Rivulus tenuis (Meek 1904) -- (Huber 1992:428 [ref. 20639], Espinosa Pérez et al. 1993:38 [ref. 22290], Greenfield & Thomerson 1997:98 [ref. 22947], Murphy & Collier 1997:797 [ref. 25585], Lazara 2001:284 [ref. 25711], Costa in Reis et al. 2003:539 [ref. 27061], Nelson et al. 2004:101 [ref. 27807], Miller 2006:208 [ref. 28615], Costa 2006:139 [ref. 28875] in subgenus Cynodonichthys, Scharpf 2007:11 [ref. 30398], Matamoros et al. 2009:12 [ref. 31241], Page et al. 2013:103 [ref. 32708], Collier 2016:41 [ref. 35018]). •Valid as Cynodonichthys tenuis Meek 1904 -- (Costa 2011:242 [ref. 31655], Lozano-Vilano & De la Maza-Benignos 2016:5 [ref. 35401], Barrientos et al. 2023:274 [ref. 41235], Page et al. 2023:140 [ref. 40505], Quintana 2024:7 [ref. 41186]). Current status: Valid as Cynodonichthys tenuis Meek 1904. Rivulidae: Rivulinae. Distribution: Southern North America, central America: Atlantic Slope river basins (Belize, Guatemala, Honduras and Mexico). Habitat: freshwater.