Description of a previously unknown population of an endangered desert fish, Poeciliopsis occidentalis occidentalis

We report a previously unknown population of Poeciliopsis occidentalis occidentalis in La Barge Creek, a tributary stream to the Salt River in Arizona. The population inhabits a slick rock canyon with four permanent pools of water. Previous translocation efforts for P. o. occidentalis occurred more than 7 km upstream of the described location in Charlebois Spring; however, this species has not been observed at the translocation site recently. It is possible that the LaBarge Creek population emigrated from Charlebois Spring. Additional sampling is necessary to determine the source of this population.