Description of Gambusia zarskei sp. n. – a new poeciliid fish from the upper Rio Conchos system, Chihuahua, Mexico (Teleostei: Cyprinodontiformes: Poeciliidae)

" Gambusia zarskei, new species, is described from the upper drainage of Rio Conchos, Rio Grande system, Chihuahua, Mexico. It is clearly distinguished by metrics, gonopodial and other morphological characteristics from all other species of the genus. A mitochondrial DNA-sequence based molecular phylogenetic analysis revealed similar results on the status of the new species as a separate taxon and its relation to other closely related species "