The axolotl ("water monster"), also known as a Mexican salamander (Ambystoma mexicanum) or a Mexican walking fish, is a neotenic salamander, closely related to the tiger salamander. Although the axolotl is colloquially known as a "walking fish", it is not a fish, but an amphibian.
As of 2010, wild axolotls were near extinction due to urbanization in Mexico City and consequent water pollution. They are currently listed by CITES as an endangered species and by IUCN as critically endangered in the wild, with a decreasing population. Axolotls are used extensively in scientific research due to their ability to regenerate limbs. Axolotls were also sold as food in Mexican markets and were a staple in the Aztec diet.
A four month long search in 2013 turned up no surviving individuals in the wild. Previous surveys in 1998, 2003 and 2008 had found 6000, 1000 and 100 axolotls per square kilometer in its Lake Xochimilco habitat, respectively.