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 Triportheus nematurus (Kner, 1858) Fig. 15 Body deep; greatest body depth contained 2.7 to 3.2 and caudal peduncle depth 10.2 to 12.1 times in SL; head length 3.6 to 4.4, predorsal distance 1.6 to 1.8 and caudal peduncle length 9.3 to 14.7 in SL; snout length 3.9 to 5.0, horizontal orbital diameter 3.0 to 3.6 and least interorbital width 2.5 to 3.6 in HL. Mouth terminal; inner row of premaxilla with 6, outer row with 6 or 7, inner row of dentary with 1, outer row of dentary with 5 or 6 and maxilla up to 2 teeth. First gill arch with 43-48 gill rakers. Lateral line 33-37 pored scales; transverse series above lateral line with 6 scale rows and below with 2 or 3 scale rows. Dorsal fin with 11, pectoral fin with 11-13, pelvic fin with 7, anal fin with 28- 34 and caudal fin with 19 rays (Malabarba, 2004). Ground color silvery; longitudinal series of dark-brown spots on flank scales above pectoral-fin origin; black blotch on posterior portion of caudal peduncle, extending to median caudal-fin rays ( Graça, Pavanelli, 2007 ). Maximum standard length. 150.0 mm ( Graça, Pavanelli, 2007 ). Distribution. Paraná-Paraguay system. Remarks. Triportheus nematurus is a non-native species from the upper rio Paraná , and its occurrence can be associated with the filling of the Itaipu Reservoir and the consequent inundation of the Sete Quedas Falls.