gymnorhynchus, Plecostomus Norman [J. R.] 1926:95 [Annals and Magazine of Natural History (Series 9) v. 18 (no. 103); ref. 15602] Iponcin Creek, into Approuague River, French Guiana. Holotype (unique): BMNH 1926.3.2.745. Type catalog: Ferraris 2007:254 [ref. 29155]. •Valid as Hypostomus gymnorhynchus (Norman 1926) -- (Isbrücker 1980:24 [ref. 2303], Burgess 1989:431 [ref. 12860], Le Bail et al. 2000:254 [ref. 24549], Isbrücker 2001:31 [ref. 25653], Isbrücker 2002:18 [ref. 27178], Weber in Reis et al. 2003:358 [ref. 27061], Armbruster 2004:79 [ref. 27644], Ferraris 2007:254 [ref. 29155], Weber et al. 2012:209, 211 [ref. 31999], Zawadzki et al. 2015:56 [ref. 33866], Zawadzki et al. 2017:571 [ref. 35666], Borstein et al. 2022:18 [ref. 39507]). Current status: Valid as Hypostomus gymnorhynchus (Norman 1926). Loricariidae: Hypostominae. Distribution: South America: Guianan coastal drainages, from Oyapock westward to Suriname basin (French Guiana and Suriname). Habitat: freshwater.