Peixes da planície de inundação do alto rio Paraná e áreas adjacentes: revised, annotated and updated Author Ota, Renata Rúbia Author Deprá, Gabriel de Carvalho Author Graça, Weferson Júnio da Author Pavanelli, Carla Simone text Neotropical Ichthyology 2018 2018-06-11 16 2 1 111 journal article 10.1590/1982-0224-20170094 f68fe85c-2a4c-4625-b684-74f61398d6c2 1982-0224 3678395 Auchenipterus osteomystax (Miranda-Ribeiro, 1918) Fig. 18 Body elongated; greatest body depth contained 4.0 to 5.9 times in SL; head length 4.5 to 4.8, anal-fin base length 2.2 to 2.5 in SL; snout length 2.3 to 2.6, horizontal orbital diameter 3.2 to 3.5, least interorbital width 2.0 to 2.7 in HL; and orbital diameter 1.7 to 2.3 in interorbital width. Mouth terminal; premaxilla and dentary with several rows of thin teeth. Dorsal fin with 7, pectoral fin with 12 or 13, pelvic fin with 13 or 14 and anal fin with 42-51 rays ( Ferraris, Jr., Vari, 1999 ). Ground color greyish dorsally, whitish ventrally. Dorsal, pelvic and anal fins hyaline; pectoral and caudal fins with distal margins black ( Graça, Pavanelli, 2007 ). Maximum standard length. 285.0 mm ( Graça, Pavanelli, 2007 ). Distribution. Río de la Plata, rio Tocantins and lower rio Amazonas basins. Remarks. Auchenipterus osteomystax is a non-native species from the upper rio Paraná its occurrence can be associated with the filling of the Itaipu Reservoir and the consequent inundation of the Sete Quedas Falls.