What Is an Axolotl?

Medically Reviewed by Amy Flowers, DVM on October 22, 2022
5 min read

Axolotls are amazing little animals. Not only do they look like they could be knockoff Pokémon, they are, in many ways, biologically unique. 

The axolotl, Ambystoma mexicanum, is a type of salamander. Salamanders are classified as amphibians along with frogs, toads, and newts. Amphibians are a class of animals that are vertebrates, meaning they have a backbone, and are cold-blooded, meaning their body relies on the environment to maintain their body temperature.

The term amphibian comes from a Greek word meaning “double life” because amphibians spend part of their life cycle in the water and part of it on land. Most amphibians, including most salamanders, spend their early days living in the water. When they go through metamorphosis, the process of changing into their mature form, their gills are replaced by lungs.

This is one area that sets the axolotl apart from most other salamanders. Axolotls are neotenic, meaning they keep many of the characteristics from their young form into their adult stage. Axolotls have both gills and lungs, though they remain in the water most of their life. They also retain juvenile traits, like a tail and body fin, that other salamanders lose in adulthood.

Like other salamanders, axolotls can regenerate parts of their bodies. So far, scientists have discovered that axolotls can regrow their:

  • Heart
  • Jaw
  • Limbs
  • Lungs
  • Parts of the brain
  • Spines

Research shows that axolotls can regrow their limbs up to five times perfectly without even a scar. Other organs may still be functional after countless regenerations. Scientists have also found that axolotls can accept organ and limb transplants from other axolotls without risk of rejection.

Due to their regenerative abilities, axolotls are popular animals for medical research. Axolotls also seem to be exceptionally resistant to cancer, which is definitely worth additional study.

Axolotls are descended from the tiger salamander, but aside from their general body shape, they don’t have much in common with their striped ancestors. 

Axolotls can grow as long as 18 inches, although nine inches is more standard. They can range in weight from 2 to 8 ounces. In the wild, axolotls are usually brown with dark mottling and may have silvery highlights. Axolotls in captivity are often bred to be white and pink. 

The axolotl’s head is wide and flat. Their mouths are often slightly upturned, making them look like they’re smiling. Eyes may be dark, but some have bright blue irises. The signature characteristic of the axolotl is the long, feathery gills on its head. Each side of the head has three frilly gills. In darker-colored axolotls, the frills are deep red or maroon, while in pale axolotls they can range from a soft pink to a vibrant fuchsia. 

Like other salamanders, axolotls have four legs with webbed feet, but their tails are very different. Instead of the thick, muscular tails that other salamanders have, the tail of the axolotl looks more like a tadpole tail, as it never matures.

Axolotls typically live between 10 and 15 years in captivity, although some may live as long as 20 years with proper care.

When axolotls are born, they’re on their own. They don’t get any help from their parents. After about six months, axolotls reach sexual maturity. They typically breed once the water starts to warm up, between March and June. A female axolotl may lay between 300 and 1,000 eggs at one time. The eggs hatch about two weeks later.

Axolotls are carnivorous predators that usually hunt at night. They use a suction method to suck up crustaceans, mollusks, insect larva, worms, and sometimes small fish. They also may suck up bits of gravel to help grind up their food and make it easier to digest.

Axolotls are only found in two freshwater lakes in Mexico: Lake Xochimilco and Lake Chalco. Unfortunately, due to human encroachment, they are critically endangered. Pollution, habitat disruption, and diversion of water for human use have caused the axolotl population to dwindle in size. There are currently only somewhere between 700 and 1,200 axolotls in the wild.

The name “axolotl” is a reflection of the creature’s homeland. Axolotls were named after the Aztec god of fire and lightning, Xolotl, who could turn into a salamander. 

Their natural habitat may offer a clue as to why axolotls never go through traditional metamorphosis. Other species of salamanders that sometimes don’t go through full metamorphosis have also been found in this area. One prevailing theory is that the lakes that hold these creatures are the perfect habitat. They’re freshwater lakes with few predators and the right temperature and pH. These lakes are also surrounded by harsh desert. If you’re born into the perfect environment, and the only other option is a hot, arid desert, why would you want to leave?

Axolotls thrive in captivity and are popular both in households and in research labs. Some states, such as New Mexico and Virginia, have strict rules on owning axolotls. California, Maine, and New Hampshire ban axolotls as pets, generally due to their endangered status.

Some states may also classify them as “exotic pets,” and as a result, certain steps must be followed before you can keep an axolotl as a pet. Check your state’s laws before buying axolotls.

Axolotls should be housed in an aquarium that’s at least 10 gallons, although 20 gallons is better. As axolotls live almost exclusively in water, no land area is needed, and the water level can be similar to that of a typical aquarium. Axolotls typically don’t like bright lighting, and the water temperature should be kept in the 60s or low 70s.

Research has shown that bloodworms are one of the best options to feed an axolotl pet. Large earthworms also work well.

Axolotls don’t need a companion in their tank, and young axolotls may end up fighting with each other. If you’re going to keep axolotls together, make sure they are all adults. Other creatures, such as fish, should not be kept with axolotls either.