A fauna de peixes nas bacias do sul do Espírito Santo, Brasil

The South Espírito Santo river basins include the Rio Itapemirim basin, the small river basins in Marataízes and a portion of the Rio Itabapoana basin, in Southeast Brazil. Nighty-two geo-referenced sites were sampled: 23 in Itabapoana, 66 in Itapemirim and three in Marataízes. A species list has been prepared, giving habitat details. Seventy-nine species, in 31 families and 11 orders were, reported, 17 species being from marine or brackish-water/estuarine habitats. The great majority of freshwater species belong to the Siluriformes (29 species), followed by the Characiformes (19). Torrential rivers, protected by the Caparaó mountains, display the lowest richness, with only a few species recorded from the highest valleys. On the other hand, in lowland river valleys along the Serra das Torres, an exceptional diversity of stream fishes was observed. Because of the only known population of Trichogenes claviger, a relictual species of Trichomycteridae, in the river Caxixe, this area is highly strategic in planning conservation of the Icthyofauna of the Itapemirim basin. Some species from southern Espírito Santo were described based on material collected on the historic Thayer Expedition, which crossed the region in 1865. Likewise, Oligosarcus acutirostris, Astyanax microschemos and Trichogenes claviger were also described based on fishes from southern Espírito Santo. A high endemism of freshwater species was observed between southern Espírito Santo rivers and lower Paraíba do Sul, suggesting a common history among these rivers.