The Axolotl, also known as the Mexican walking fish, is a neotenic salamander native to Mexico. Despite the name, Axolotls are amphibians, but live exclusively in the water and bear a strong resemblance to fish. Axolotls are a model example of neoteny, the retention of juvenile characteristics throughout adulthood. This neoteny makes the adult Axolotl appear more tadpole-like than fully grown salamanders; as a result the Axolotl requires less food than fully matured salamanders. Unfortunately, due to the draining of lake Chalco and the urbanization of Mexico city, the Axolotl was declared extinct in the wild in 2013. Never the less, Axolotls are frequently kept as pets, and are extensively studied by biologists due to their extensive regenerative abilities.