The axolotl is an amphibian and a type of salamander. 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. An axolotl has feathery gills on the outside of its head for breathing underwater. Grown axolotls have working lungs as well as gills. They can also breathe through their skin.

Wild axolotls are mostly dark in color. They are black, brown or gray. An axolotl can reach about 12 inches long. It 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 too, which helps grind up its food. Storks, herons and large fish sometimes eat axolotls.

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. Axolotls can also regrow hearts and parts of the brain. After an injury, a mass of cells called a blastema forms and can grow back the missing part. Axolotls also heal wounds without forming scar tissue. Because of this ability, axolotls are a common research subject for biologists.

Axolotls come from lakes and wetlands in southern Mexico City, in Mexico. They once lived in a series of lakes and wetlands in the Mexican Central Valley. Many of those lakes have been drained to reduce flooding. Urbanization and pollution of their lakes are the biggest threats. Fish such as tilapia and carp compete with axolotls for food and eat their young. In 1864, 34 living axolotls were brought from Mexico to Paris.

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. The number of wild axolotls is decreasing. Wild axolotls live 10 to 15 years. Farmers are increasingly using traditional farming methods, free of pesticides and fertilizers, to help conserve axolotls.

Words to know

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