tenebrosus, Imparfinis Schubart [O.] 1964:9, Figs. 3-4 [Boletim do Museu Nacional do Rio de Janeiro, Zoologia, Nova Série No. 244; ref. 3417] Rio Mogi Guaçu, Brazil. Syntypes: EEBP 109 (1), 197 (5), 197 (bis) (?), 630 (4). Type catalog: Ferraris 2007:189 [ref. 29155]. •Valid as Heptapterus tenebrosus (Schubart 1964) -- (Burgess 1989:277 [ref. 12860]). •Valid as Phenacorhamdia tenebrosa (Schubart 1964) -- (Britski 1993:45 [ref. 21110], Burgess & Finley 1996:167 [ref. 22901], Casatti et al. 2001:5 [ref. 25929], Bockmann & Guazzelli in Reis et al. 2003:416 [ref. 27061], Ferraris 2007:189 [ref. 29155], DoNascimiento & Milani 2008:165 [ref. 29737], Koerber 2014:7 [ref. 33621], Mirande & Koerber 2015:34 [ref. 35117], Rocha et al. 2018:360 [ref. 35864], Azevedo-Santos et al. 2020:6 [ref. 39606], Reis et al. 2020:466 [ref. 38364], Silva et al. 2020:10 [ref. 37809], Silva 2020:281 [ref. 37978], Vieira-Guimarães et al. 2024:44 [ref. 41258]). Current status: Valid as Phenacorhamdia tenebrosa (Schubart 1964). Heptapteridae: Heptapterinae. Distribution: South America: upper Paraná and São Francisco River basins (Argentina and Brazil). Habitat: freshwater.