Historical records of this species indicate presence in six municipalities near Toluca between 2,500-3,000 m asl. Currently, it is restricted to the central highlands of the State of Mexico, near the city of Toluca, in the Río Lerma and the Lerma Lake around Almoloya (Area de Protección de Flora y Fauna Ciénagas de Lerma). It has an extent of occurrence of 303 km
Habitat and Ecology
It is a variable species, with individuals capable of reaching sexual maturity either in the metamorphosed or larval stage. Metamorphosed individuals spend most of the time on land in grassland habitat. It breeds in streams, lakes and moderately deep reservoirs.
Since the species was last assessed (2008), the species has been recorded in the three lagoons of the Ciénegas de Lerma protected area. Populations in one of the lagoons seems relatively healthy, and for the other two lagoons there are records of malformations and pollution, where the sub-populations are decreasing.
The extremely high degree of pollution of the rivers and pools where this species breeds has contributed to its decline. There is also a serious problem of habitat loss due to urban expansion. In addition, animals have been captured for food consumption and for medicinal purposes, and introduced predatory fish and the American Bullfrog (Lithobates catesbeianus) might also be a threat.
Additional work differentiating this species from nearby populations of Ambystoma velasci is needed (Shaffer and McKnight 1996).
IUCN SSC Amphibian Specialist Group 2015. Ambystoma lermaense. In: IUCN 2014