Gambusia eurystoma
Overview
The widemouth gambusia is a species of fish in the family Poeciliidae of the order Cyprinodontiformes. It is endemic to Mexico, specifically to the Baños del Azufre near Teapa, Tabasco. The Baños del Azufre are sulfidic springs that contain high concentrations of toxic hydrogen sulfide. This prevents most animals from living in them; the only other fish found in the toxic sections of Baños del Azufre is the sulphur molly.
Gambusia eurystoma faces severe threats from habitat destruction and water extraction in its extremely limited range in northeastern Mexico. The species is confined to a few spring systems that are increasingly impacted by agricultural water diversion and urban development. Introduced species, particularly other Gambusia species and larger predatory fish, pose additional pressure through competition and predation on this endemic pupfish.
Habitat
This species is endemic to freshwater spring systems and associated pools in the Cuatro Ciénegas basin of Coahuila, Mexico. It inhabits shallow, clear waters with constant temperatures and specific mineral compositions typical of desert spring ecosystems.
