440

Lake Patzcuaro Salamander

Central America

440

Ambystoma dumerilii

Endangered

The filling and pollution of the only lake that the species inhabits is the major threat to its survival. The lake is an important area for local fisheries. Predatory fish have been introduced into the lake, which might be a major problem for the species, although it has been able to co-exist with such species for a long time.

Ambystoma dumerilii is a neotenic salamander found only in Lake Pátzcuaro, Mexico. A sexually mature specimen measures, from snout to vent, over 122 mm; there is no body length difference between the sexes. Of preserved specimens, total size ranges from 128-282 mm (Brandon 1970). Distinct features include a flat, wide head, caudal fins, and few rakers on the third gill arch’s anterior surface (the exact number is disputed). The salamander can also be identified by perennibranchiate (lifelong), hyperfilamentous gills and diminutive, webbed toes with the fourth digit possessing three phalanges. This animal is tan to brown and homogenous in coloration.

The amphibian is known historically and currently to inhabit only Lake Pátzcuaro in the Mexican state of Michoacan. Rumors of salamander sightings in San Juan del Rio, Queretaro, are highly unlikely due to geographic isolation. Area of occurrence is less than 100 km2, the occupancy area less than 10 km2.