Distribution, abundance and use of different environments by dominant ichthyofauna in the influence area of the Itaipu Reservoir

Abstract

The aim of this paper is to characterize the structure of dominant ichthyofauna in the Itaipu reservoir and its area of influence. 85,160 individuals were collected during the period from November 1983 to October 1989 in 11 sample sites, or rather, in the dam area (Guaíra, Santa Helena and Foz do Iguaçu), in the tributaries of its left bank (the rivers Arroio Iguaçu, Ocoí, São Francisco Falso and São Francisco Verdadeiro), in upstream and downstream Paraná River, in the tributaries of the Paraná River (Piquiri and Iguatemi). Results showed a great number of species with low frequency and few dominant species. Among the dominant species Auchenipterus nuchalis, Hypophthalmus edentatus, Iheringichthys labrosus, Loricariichthys sp, Parauchenipterus galeatus, Plagioscion squamosissimus, Prochilodus lineatus, Pterodoras granulosus, Rhaphiodon vulpinus and Steindachnerina insculpta are conspicuous. The places of the feeding, reproduction and initial development places to the dominant species were identified.