melanistius, Corydoras Regan [C. T.] 1912:216 [Annals and Magazine of Natural History (Series 8) v. 10 (no. 56); ref. 14865] Essequibo River, Guyana. Lectotype: BMNH 1864.1.21.86. Paralectotypes: BMNH 1864.1.21.87 (1). Type catalog: Ferraris 2007:120 [ref. 29155]. Lectotype selected by Nijssen & Isbrücker 1967:32 [ref. 7981]. •Valid as Corydoras melanistius Regan 1912 -- (Ovchynnyk 1967:37 [ref. 37559], Nijssen & Isbrücker 1980:197 [ref. 6910], Burgess 1989:366 [ref. 12860], Isbrücker 2001:229 [ref. 26805], Reis in Reis et al. 2003:299 [ref. 27061], Ferraris 2007:120 [ref. 29155], Tencatt & Pavanelli 2015:294 [ref. 35434], Tencatt & Ohara 2016:[13] [ref. 34353], Tencatt & Evers 2016:[11] [ref. 34387], Tencatt et al. 2016:[17] [ref. 34388], Ottoni et al. 2016:133 [ref. 34756], DoNascimiento et al. 2017:73 [ref. 35633], Taphorn et al. 2022:45 [ref. 41297], Tencatt et al. 2023:20 [ref. 40562]). •Valid as Hoplisoma melanistium (Regan 1912) -- (Dias et al. 2024:27 [ref. 41219]). Current status: Valid as Hoplisoma melanistium (Regan 1912). Callichthyidae: Corydoradinae. Distribution: South America: coastal rivers (Colombia, French Guiana, Guyana, Suriname, ?Venezuela). Habitat: freshwater.