Diversidade de peixes migradores da Bacia Tocantins-Araguaia, Brasil

Abstract

Migration upstream is a common behavior for many species around the world, including in South America, where many potamodromous species are observed that spawn in upper reaches and tributaries of watersheds. In this context, among the Brazilian migratory ichthyofauna, the Tocantins-Araguaia basin stands out, due to the richness of species presented and the size of the drainage area it occupies (767,000 km²). Based on this, the objective of the present work was to identify the species of migratory fish for the basin, where the taxonomic and functional traits of 77 species of migratory fish were identified and described. Our results allowed observing that the species colonize the main rivers that form the basin, due to the connection in the lower Tocantins River. Furthermore, we observed that most species have a wide distribution; however, despite presenting a functional and taxonomic redundancy along the drainage, some migrants are restricted to single stretches within the basin. In view of this, we reinforce the need to conserve these rivers and their tributaries, as the entire basin has been used as a survival habitat and migration route.