Details
Ambystoma mexicanum
The axolotl is a Mexican salamander that matures while keeping its larval gills and aquatic form. It is famous both as a wild survivor of ancient lake systems and as a laboratory model for regeneration.
Map: Ecoregions 2017 © RESOLVE (CC BY 4.0) · Natural Earth (PD)
Wild axolotls are now largely confined to the Xochimilco lake and canal system in the Basin of Mexico. They use vegetated freshwater, but urban growth, pollution, and introduced fishes have greatly reduced suitable habitat.
Adults are about 15-30 cm long. A broad head carries three feathery external gills on each side, and the slender body has a fin-edged tail. Wild types are dark and mottled, while captive lines include white, golden, and other colour forms.
Nocturnal and solitary, it shelters on the bottom or among aquatic plants. It normally does not metamorphose, retaining gills and fins while becoming sexually mature. Lost limbs, tail, gills, and some tissues can regenerate.
Carnivorous, it eats small crustaceans, insect larvae, worms, and small fish. Prey is taken by a rapid suction strike, with the broad mouth drawing in food and water together.
Breeding takes place underwater: the male deposits spermatophores and the female picks them up for internal fertilization. She attaches many individual eggs to plants and other surfaces; hatching follows after several weeks depending on temperature.
The species is Critically Endangered in the wild despite being common in captivity and research. Introduced fish, polluted water, and continuing development remain major pressures on the remnant native population.
