derbyi, Plecostomus Haseman [J. D.] 1911:384, Pls. 79-81 [Annals of the Carnegie Museum v. 7 (nos 3-4) (19); ref. 2048] Rio Iguaçu at Porto União da Victoria, Brazil. Holotype (unique): FMNH 54246 [ex CM 2865]. Type catalog: Henn 1928:84 [ref. 12305], Ibarra & Stewart 1987:67 [ref. 12367], Ferraris 2007:253 [ref. 29155]. •Valid as Hypostomus derbyi (Haseman 1911) -- (Mirande & Koerber 2015:42 [ref. 35117], Cardoso et al. 2016:22 [ref. 34373], Zawadzki et al. 2016:272 [ref. 34908], Koerber et al. 2017:61 [ref. 35267], Zawadzki et al. 2018:[16] [ref. 35944], Zawadzki et al. 2019:[11] [ref. 37170], Reis et al. 2020:467 [ref. 38364]). Current status: Valid as Hypostomus derbyi (Haseman 1911). Loricariidae: Hypostominae. Distribution: South America: Iguaçu River and Uruga-í Creek basins, Paraguayan tributaries of Paraná River basin (Argentina, Brazil, Paraguay). Habitat: freshwater.