Fish diversity from tributaries of the Chavantes Reservoir, upper Paraná River basin, PR

Distribution and abundance of stream fish species can be influenced by environmental characteristics related to the aquatic environment and its margins. The objective of this study was to inventory the ichthyofauna of the Cruz, Taquaruçu, and Taquaruçu II streams, in the Paranapanema River basin, and to analyze the diversity parameters and associate them with abiotic variables. A total of 4,956 specimens were collected, in 27 species, with a predominance of Characiformes and Siluriformes. The greater width, depth, and the riparian forest are the environmental variables that best explain the higher diversity of species in the Taquaruçu II stream, while the species dominance observed in the Cruz and Taquaruçu streams may reflect anthropogenic impacts, such as high degree of erosion. Hydrological connectivity could be related to the greater similarity in species composition between the Cruz and Taquaruçu streams. Electrical conductivity and width of the streams were the abiotic variables that correlated the most with the abundance and diversity of species in the sampled streams. The results of this study demonstrate the ecological importance of conserving aquatic ecosystems to maintain fish diversity, in addition to showing the effect of anthropogenic impacts on the ichthyofauna