A new species of livebearer has been described from Mexico in the latest issue of the journal Vertebrate Zoology.
Manfred Meyer, Susanne Schories and Manfred Schartl name the new livebearer Gambusia zarskei after German ichthyologist Axel Zarske.
Gambusia zarskei is known from the upper Rio Conchos system in the Sierra San Diego area, east of San Diego de AlcalaÌ, Chihuahua, Mexico, and is distinguished from congeners by its gonopodial morphology, the presence of 8 dorsal-fin rays and a black anal spot.
An analysis of a partial sequence of the mitochondrial cytochrome b gene confirms the distinctiveness of this species.
The new species inhabits streams with clear water, a rapid current and a substrate of gravel and sand. Water parameters measured at the type locality were: temperature 24–26°C, conductivity 1486 mS, pH 7.85, and total hardness 9.
For more information, see the paper: Meyer, MK, S Schories and M Schartl (2010) Description of Gambusia zarskei sp. n. – a new poeciliid fish from the upper Rio Conchos system, Chihuahua, Mexico (Teleostei: Cyprinodontiformes: Poeciliidae). Vertebrate Zoology 60, pp. 11–18.