Species that contain: Olivaichthys and viedmensis [ 3 ] records

cuyanus, Diplomystes viedmensis Ringuelet [R. A.] 1965:91 [Physis (Buenos Aires) v. 25 (no. 69); ref. 9247] Arroyo Taucha [Yaucha], Vilucó, Province of Mendoza, Argentina. Holotype: MLP 286. Paratypes: MLP 948 (1). Type catalog: Ferraris 2007:166 [ref. 29155], Miquelarena & Nadalin 2014:10 [ref. 33466]. •Valid as Olivaichthys cuyanus (Ringuelet 1965) -- (de Pinna 1998:291 [ref. 23847], Ferraris in Reis et al. 2003:256 [ref. 27061], Ferraris 2007:166 [ref. 29155]). •Valid as Diplomystes cuyanus Ringuelet 1965 -- (Azpelicueta 1994:228 [ref. 22312], Azpelicueta 1994:13 [ref. 22377], Burgess & Finley 1996:163 [ref. 22901], Azpelicueta & Gosztonyi 1998:902 [ref. 25377], López et al. 2002:60 [ref. 26808], López et al. 2003:37 [ref. 27366], Lundberg et al. 2004:72 [ref. 27673], Menni 2004:79 [ref. 28131], Muñoz-Ramírez et al. 2014:148 [ref. 33192] with remarks, Mirande & Koerber 2015:27 [ref. 35117], Muñoz-Ramírez et al. 2023:8 [ref. 40526]). Current status: Valid as Diplomystes cuyanus Ringuelet 1965. Diplomystidae. Distribution: South America: several river basins in southern Argentina (Pacific drainage). Habitat: freshwater.

mesembrinus, Diplomystes viedmensis Ringuelet [R. A.] 1982:349, Figured (p. 350) [Limnobios (La Plata) v. 2 (no. 5); ref. 8984] Mouth of Senguer River, 45°60'S, 49°10'W, Province of Chubut, Argentina. Holotype (unique): MLP 8452. Type catalog: Ferraris 2007:166 [ref. 29155], Koerber 2007:2 [ref. 29776] with corrections, Miquelarena & Nadalin 2014:10 [ref. 33466]. •Valid as Olivaichthys mesembrinus (Ringuelet 1982) -- (Ferraris in Reis et al. 2003:256 [ref. 27061], Ferraris 2007:166 [ref. 29155]). •Valid as Diplomystes mesembrinus Ringuelet 1982 -- (Azpelicueta 1994:231 [ref. 22312], Azpelicueta 1994:13 [ref. 22377], Burgess & Finley 1996:163 [ref. 22901], Azpelicueta & Gosztonyi 1998:902 [ref. 25377], López et al. 2002:60 [ref. 26808], López et al. 2003:37 [ref. 27366], Lundberg et al. 2004:72 [ref. 27673], Menni 2004:79 [ref. 28131], Muñoz-Ramírez et al. 2014:146 [ref. 33192], Mirande & Koerber 2015:27 [ref. 35117], Muñoz-Ramírez et al. 2023:8 [ref. 40526]). Current status: Valid as Diplomystes mesembrinus (Ringuelet 1982). Diplomystidae. Distribution: South America: Baker, Chubut and Senguer River basins, Argentina. Habitat: freshwater.

viedmensis, Diplomystes MacDonagh [E. J.] 1931:65 [Notas Preliminares del Museo de La Plata v. 1; ref. 16301] Río Negro, vicinity of Viedma, Province of Río Negro, Argentina. Holotype: MLP 214 [ex 19-III-31.3]. Paratypes: MLP 8966 [ex MCILP 19-III-31-1] (1); ?MCLIP 19-III-31-2 (1). Type catalog: Ferraris 2007:166 [ref. 29155], Miquelarena & Nadalin 2014:10 [ref. 33466]. •Valid as Olivaichthys viedmensis (MacDonagh 1931) -- (de Pinna 1998:291 [ref. 23847] on Arratia 1987, Ferraris in Reis et al. 2003:256 [ref. 27061], López et al. 2003:37 [ref. 27366], Ferraris 2007:166 [ref. 29155], Arratia & Quezada-Romegialli 2017:6 [ref. 35155]). •Valid as Diplomystes viedmensis MacDonagh 1931 -- (Arratia 1987:68 [ref. 5957], Burgess 1989:25 [ref. 12860], Azpelicueta 1994:224 [ref. 22312], Azpelicueta 1994:12 [ref. 22377], Azpelicueta & Gosztonyi 1998:901 [ref. 25377], López et al. 2002:60 [ref. 26808], Lundberg et al. 2004:72 [ref. 27673], Menni 2004:79 [ref. 28131], Muñoz-Ramírez et al. 2014:146 [ref. 33192], Mirande & Koerber 2015:28 [ref. 35117], Muñoz-Ramírez et al. 2023:8 [ref. 40526]). Current status: Valid as Diplomystes viedmensis MacDonagh 1931. Diplomystidae. Distribution: South America: Negro River basin, Argentina and Chile. Habitat: freshwater.