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 Gymnorhamphichthys britskii Carvalho, Ramos, Albert, 2011 Fig. 17 Body elongated and compressed; greatest depth contained 16.6 to 17.9 times in TL; head length 8.5 to 8.7, anal-fin base length 1.4 to 1.6, caudal peduncle length 4.9 to 6.0, preanal distance 7.7 to 8.3 and prepectoral distance 7.8 to 8.2 in LEA; snout length 1.7 to 2.3, horizontal orbital diameter 11.5 to 17.5 and least interorbital width 8.9 to 14.9 in HL. Mouth subterminal; snout relatively short. Pectoral fin with 13-15 rays and anal fin with 141-172 rays ( Graça, Pavanelli, 2007 ; Carvalho et al. , 2011 ). Ground color pale yellow; three dark-brown inconspicuous longitudinal stripes on flank; darkbrown transverse bars on dorsolateral region. Hyaline fins. Maximum total length. 180.0 mm. Biological data. Lives in different habitats, from small streams to large size rivers ( Carvalho et al. , 2011 ). Distribution. Río de La Plata basin. Remarks. Gymnorhamphichthys britskii was identified as Gymnorhamphichthys sp. by Graça, Pavanelli (2007) . Carvalho et al. (2011) described the new species from the río de La Plata basin. Gymnorhamphichthys britskii has been sampled in the upper rio Paraná floodplain recently, with no anterior records in the basin. Therefore, this species is considered as non-native from the upper rio Paraná , and its occurrence in the region can be associated with its introduction as a live bait by anglers, or with the filling of the Itaipu Reservoir and the consequent inundation of the Sete Quedas Falls.