Description of Priapella chamulae sp. n. - a new poeciliid fish from the upper río Grijalva system, Tabasco, Mexico (Teleostei: Cyprinodontiformes: Poeciliidae)

" Priapella chamulae, new species, is described from the tributaries of río Tacotalpa and río Pichucalco, río Grijalva system, Tabasco, Mexico. It is clearly distinguished by metrics, gonopodial and other morphological characteristics from all other species of the genus. A mitochondrial DNAsequence based molecular phylogenetic analysis revealed similar results on the status of the new species as a separate taxon and its relation to the other closest related species "