Simpsonichthys de Carvalho

Wilson J. E. M. Costa & Gilberto C. Brasil, 2006, Three new species of the seasonal killifish genus Simpsonichthys, subgenus Hypsolebias (Teleostei: Cyprinodontiformes: Rivulidae) from the rio Paracatu drainage, rio São Francisco basin, Brazil., Zootaxa 1244, pp. 41-55 : 42

[[ Simpsonichthys de Carvalho ]]

Simpsonichthys de Carvalho is the most diversified genus of seasonal aplocheiloid killifishes, comprising 44 valid species (Costa, 2005, 2006). Species of Simpsonichthys occur over a vast neotropical area, including the Amazonas, Paraná-Paraguay, and São Francisco river basins of northeastern, central, and eastern South America, and in several other smaller coastal rivers basins (Costa, 2006). The greatest diversification is concentrated in the rio São Francisco basin, with 19 endemic species (Costa, 2005, 2006). Six species ( S. trilineatus (Costa & Brasil, 1994) ; S. auratus Costa & Nielsen, 2000 ; S. similis Costa & Hellner, 1999 ; S. alternatus (Costa & Brasil, 1994) ; S. delucai Costa, 2003 ; and S. zonatus (Costa & Brasil, 1990) ) are endemic to the rio Paracatu and rio Urucuia drainages, two adjacent drainages constituting the southwestern portion of the rio São Francisco basin. Among them, four species form two well corroborated clades ( S. trilineatus and S. auratus , and S. alternatus and S. delucai ), with all four hypothesized to be more closely related to species of Simpsonichthys endemic to the rio Tocantins basin than to congeners occurring in other parts of the rio São Francisco basin (Costa, 1996, 2003, 2006). Three new species belonging to these clades were collected by the second author in the middle rio Paracatu drainage, and are herein described.