margaritifer, Plecostomus Regan [C. T.] 1908:796, Pl. 47 (fig. 2) [Proceedings of the Zoological Society of London 1907 (pt 4); ref. 14333] Rio Piracicaba, San Paulo, Brazil. Holotype (unique): BMNH 1907.7.6.14. Type catalog: Ferraris 2007:256 [ref. 29155]. •Valid as Hypostomus margaritifer (Regan 1908) -- (Isbrücker 1980:27 [ref. 2303], Burgess 1989:431 [ref. 12860], Isbrücker 2001:28, 31 [ref. 25653], Isbrücker 2002:19 [ref. 27178], Weber in Reis et al. 2003:360 [ref. 27061], Armbruster 2004:79 [ref. 27644], Ferraris 2007:256 [ref. 29155], Zawadzki et al. 2016:273 [ref. 34908], Zawadzki et al. 2017:12 [ref. 35355], Ramos et al. 2017:8 [ref. 35396] as cf. margaritifer, Zawadzki et al. 2018:[16] [ref. 35944], Zawadzki et al. 2018:[16] [ref. 35944], Zawadzki et al. 2019:[11] [ref. 37170], Azevedo et al. 2021:4 [ref. 38203], Reis et al. 2020:467 [ref. 38364], Zawadzki & Azevedo 2024:325 [ref. 41237]). Current status: Valid as Hypostomus margaritifer (Regan 1908). Loricariidae: Hypostominae. Distribution: South America: upper and middle Paraná River basin (Brazil and ?Paraguay). Habitat: freshwater.