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.