Doradidae

Four thorny catfishes successfully invaded the upper rio Paraná after Itaipu: Oxydoras eigenmanni (= Doras eigenmanni in Zawadzki et al., 1996), Platydoras armatulus, Pterodoras granulosus, and Trachydoras paraguayensis, as already stated by Zawadzki et al. (1996). The only native doradid species upstream from the Falls was Rhinodoras dorbignyi, which remains hitherto cohabiting with congeners. Some of the introduced species became common, such as T. paraguayensis, especially in the years just after the impoundment, and P. granulosus, currently the second most important species in biomass considering artisanal fisheries in the Itaipu Reservoir (Okada et al., 2005). Oxydoras kneri is the only thorny catfish native to the rio Paraná basin below Sete Quedas Falls that did not colonize the upper rio Paraná after Itaipu.