Axolotl

Axolotl
In the National Aquarium in Washington, D.C.
Conservation status
Critically Endangered  (IUCN 3.1)[1]
CITES Appendix II (CITES)[2]
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Amphibia
Order:	Urodela
Family:	Ambystomatidae
Genus:	Ambystoma
Species:	A. mexicanum
Binomial name
Ambystoma mexicanum (Shaw and Nodder, 1798)
IUCN range of the Axolotl.   Axolotl (Ambystoma mexicanum)
Synonyms[3]
Gyrinus mexicanus Shaw and Nodder, 1798 Siren pisciformis Shaw, 1802 Siredon axolotl Wagler, 1830 Axolotes guttata Owen, 1844 Siredon Humboldtii Duméril, Bibron, and Duméril, 1854 Amblystoma weismanni Wiedersheim, 1879 Siredon edule Dugès, 1888

The axolotl (/ˈæksəlɒtəl/ ^ⓘ; from Classical Nahuatl: āxōlōtl [aːˈʃoːloːtɬ] ^ⓘ) (Ambystoma mexicanum)^[3] is a paedomorphic salamander closely related to the tiger salamander.^[3][4][5] It is unusual among amphibians in that it reaches adulthood without undergoing metamorphosis. Instead of taking to the land, adults remain aquatic and gilled. The species was originally found in several lakes underlying what is now Mexico City, such as Lake Xochimilco and Lake Chalco.^[1] These lakes were drained by Spanish settlers after the conquest of the Aztec Empire, leading to the destruction of much of the axolotl's natural habitat.

As of 2020^[update], the axolotl was near extinction^[6][7] due to urbanization in Mexico City and consequent water pollution, as well as the introduction of invasive species such as tilapia and perch. It is listed as critically endangered in the wild, with a decreasing population of around 50 to 1,000 adult individuals, by the International Union for Conservation of Nature and Natural Resources (IUCN) and is listed under Appendix II of the Convention on International Trade in Endangered Species (CITES).^[2] Axolotls are used extensively in scientific research due to their ability to regenerate limbs, gills and parts of their eyes and brains.^[8] Notably, their ability to regenerate declines with age, but it does not disappear. Axolotls keep modestly growing throughout their life and some consider this trait to be a direct contributor to their regenerative abilities.^[9] Further research has been conducted to examine their heart as a model of human single ventricle and excessive trabeculation.^[10] Axolotls were also sold as food in Mexican markets and were a staple in the Aztec diet.^[11]

Axolotls may be confused with the larval stage of the closely related tiger salamander (A. tigrinum), which are widespread in much of North America and occasionally become paedomorphic, or with mudpuppies (Necturus spp.), fully aquatic salamanders from a different family that are not closely related to the axolotl but bear a superficial resemblance.^[12]