gymnogenys, Geophagus Hensel [R.] 1870:61 [Archiv für Naturgeschichte v. 36 (pt. 1); ref. 18277] Rio Cadeia, Rio Grande do Sul, Brazil. Lectotype: ZMB 7465. Paralectotypes: ZMB 22296 (11), 22299 (4). Type catalog: Paepke & Schindler 2013:268 [ref. 32895]. Lectotype selected by Gosse 1976:119 [ref. 7029]. •Valid as Gymnogeophagus gymnogenys (Hensel 1870) -- (Gosse 1976:117 [ref. 7029], Reis & Malabarba 1988:277 [ref. 6638], Malabarba 1989:167 [ref. 14217], Wimburger et al. 1998:510 [ref. 23857], Casciotta et al. 2000:53 [ref. 24908], Kullander in Reis et al. 2003:635 [ref. 27061], López et al. 2003:77 [ref. 27366], Menni 2004:87 [ref. 28131], Staeck 2006:104 [ref. 29421], González-Bergonzoni et al. 2009:21 [ref. 30455], Litz & Koerber 2014:34 [ref. 33622], Malabarba et al. 2015:660 [ref. 34105], Mirande & Koerber 2015:58 [ref. 35117], Bertaco et al. 2016:426 [ref. 34561], Nión et al. 2016:50 [ref. 35565], Koerber et al. 2017:8 [ref. 35083], Koerber et al. 2017:9 [ref. 35632] not from Argentina, Casciotta et al. 2017:20 [ref. 35727], Alonso et al. 2019:S1 [ref. 36529], Mirande & Koerber 2020:2 [ref. 37594], Loureiro et al. 2023:152 [ref. 40506]). Current status: Valid as Gymnogeophagus gymnogenys (Hensel 1870). Cichlidae: Cichlinae. Distribution: South America: southeastern Brazil and Uruguay. Habitat: freshwater.