You may have heard the axolotl called the Mexican walking fish. It is sometimes called that, though it is not a fish at all. The axolotl is an amphibian. It is a type of salamander, and its closest relative is the tiger salamander. The word axolotl comes from Nahuatl, a language of the Aztecs. An axolotl lives in the water for its whole life. Axolotls are neotenic, which means they keep young traits when they are grown. They never grow up to become adult salamanders.

One idea is that axolotls stay in the water because their native lakes never dry up. If so, they never had to trade water traits for land ones. Axolotls once lived in a series of lakes and wetlands in the Mexican Central Valley. Many of those lakes have been drained to reduce flooding. The Xochimilco-Chalco basin was once about 200 square kilometers of marshes, swamps and lagoons. It was greatly reduced when drainage projects were completed.

An axolotl has feathery gills on the outside of its head for breathing underwater. Grown axolotls also have working lungs. They can breathe through their skin too. An axolotl has a tail with a fin. It has small, underdeveloped teeth. It has no movable eyelids. It can reach about 12 inches long. Wild axolotls are mostly dark in color: black, brown or gray. Axolotls communicate visually and chemically. They can also sense electrical impulses in the water to locate prey.

An axolotl hides in mud and plants during the day and is active at night. It eats worms, insect larvae and small fish. It catches food by sucking it in. It may suck up gravel, which helps grind up its food. A female axolotl lays her eggs on plants or rocks. The eggs hatch after about two weeks. Young axolotls get no parental care. Wild axolotls live 10 to 15 years.

An axolotl can regrow a lost leg in a few weeks to months. When it does, every tissue is replaced, including skin, bone, cartilage and muscle. After an injury, a mass of cells called a blastema forms and can regrow the missing part. Axolotls also heal wounds without forming scar tissue. As a salamander gets older, its ability to regenerate decreases. But old salamanders still regenerate missing or damaged tissues. Biologists often study axolotls because of this ability.

Urbanization and pollution of their lakes are the biggest threats to axolotls. Fish put into the waterways, such as tilapia and carp, compete with axolotls for food and eat their young. As of November 2026, the IUCN Red List lists the axolotl as Critically Endangered. An IUCN assessment found only 50 to 1,000 axolotls left in the wild, and the number of wild axolotls is decreasing. Farmers are increasingly using traditional farming methods, free of pesticides and fertilizers, to help conserve axolotls.

Words to know

• neotenic: keeping young traits
• amphibian: animal group
• blastema: mass of cells
• conserve: protect