orbignyanus, Tetragonopterus Valenciennes [A.] in Cuvier & Valenciennes 1850:147 [Histoire naturelle des poissons v. 22; ref. 1014] Buenos Aires, Argentina. Syntypes: MNHN 0000-4530 (1, poor condition), A-9816 to 9818 (2, 1, 1). Type catalog: Bertin 1948:19 [ref. 19577]. •Valid as Astyanax orbignyanus (Valenciennes 1850) -- (Buckup in Reis et al. 2003:111 [ref. 27061], Mirande & Koerber 2015:24 [ref. 35117]). •Species inquirenda -- (Lucena & Soares 2016:118 [ref. 34169], Zanata & Bertaco 2024:110 [ref. 40817]). Current status: Uncertain as Astyanax orbignyanus (Valenciennes 1850). Acestrorhamphidae: Acestrorhamphinae. Distribution: South America: lower La Plata River basin, Argentina. Habitat: freshwater.