Ichthyofauna of the Rio Verde Grande, middle São Francisco basin, eastern Brazil (Actinopterygii, Teleostei)

Tributaries of the middle Rio São Francisco basin, including the Rio Verde Grande, are important nursery habitats for reproduction of migratory fishes and provide water for economic activities such as agriculture, but the characterization of the fish fauna in these areas remains understudied. We document the presence of 53 species across 43 genera within 21 families in the Rio Verde Grande, encompassing the otophysan orders Characiformes (30 species), Gymnotiformes (two species), and Siluriformes (16 species), as well as the percomorph families Cichlidae (two species) and Poeciliidae (three species). Megalamphodus eques and Poecilia reticulata are non-native species and introduced in the Rio Verde Grande and along the São Francisco basin. The sampling site near Jaíba situated at the lowest altitude of 467 m a.s.l. harbored the highest species richness among all sites with 37 species representing 62% of the overall richness and was completely dry in 2019. Analysis of ecological trait factors resulted in assemblage dominated by medium- and large-bodied fishes, prevalence of benthic feeding strategies, and habitat association with lotic environments. This survey represents a baseline for future regional initiatives that require the development of conservation plans focused on the Rio Verde Grande that can thus maintain the unique freshwater species diversity.