longicauda, Pimelodus (Rhamdia) Boulenger [G. A.] 1887:275, Pl. 20 (fig. 2) [Proceedings of the Zoological Society of London 1887 (pt 2) (art. 2) (for 1 Mar. 1887); ref. 532] Canelos, eastern Ecuador. Syntypes: BMNH 1880.12.8.100-104 (5). Type catalog: Ferraris 2007:185 [ref. 29155]. The specific name is an indeclinable noun. •Valid as Rhamdia longicauda (Boulenger 1887) -- (Ovchynnyk 1967:35 [ref. 37559], Ortega & Vari 1986:15 [ref. 9708], Burgess 1989:279 [ref. 12860]). •Valid as Imparfinis longicauda (Boulenger 1887) (often seen as longicaudus) -- (Mees & Cala 1989:383 [ref. 14277], Bockmann & Guazzelli in Reis et al. 2003:414 [ref. 27061], Ferraris 2007:185 [ref. 29155], Ortega-Lara et al. 2011:778 [ref. 31716], Barriga Salazar 2014:114 [ref. 35745], Castro & Wosiacki 2019:471 [ref. 37139], Deprá et al. 2023:147 [ref. 39829]). Current status: Valid as Imparfinis longicauda (Boulenger 1887). Heptapteridae: Heptapterinae. Distribution: South America: Bobonaza River basin in upper Partaza River drainage (Ecuador) and Rio Corrente (Brazil). Habitat: freshwater.