8 Fascinating Facts About the Axolotl (2024)

Axolotls (pronounced ak·suh·laa·tls) are aquatic salamanders that are found in the wild in only one place, Lake Xochimilco in Mexico City. These critically endangered amphibians are also popular as pets and are bred in captivity for scientific research due to their unique ability to regrow body parts. Habitat destruction and the introduction of invasive fish species have led to a dramatic decline in the axolotl population.

These amphibians are small in size, come in a range of colors, and maintain their larval traits throughout their entire lives. Their unusual appearance, often featuring bright pink skin and frilly headdresses (which are their gills, in fact), has made them beloved by many fans around the world. These solitary animals are not unfriendly or antisocial, but they're also quite happy to be left alone. They are fully aquatic, so if you keep them as a pet, you will not be able to have direct interaction, but they are entertaining to watch.

From their quirky mating dances to their amazing regenerative traits, discover the most fascinating facts about the axolotl.

1. Axolotls Look Like Babies for Their Entire Lives

Axolotls are "neotenic" creatures, meaning they achieve sexual maturity without losing any of their larval features. So while many amphibians, like the salamander, will eventually develop lungs and live on land, axolotls keep their trademark feathery external gills and remain aquatic. This also means that their teeth never develop and that they must rely on a suction method to consume food.

Sometimes, when eating, their mouths remain open for a few seconds after swallowing, which can make them look like they're smiling. Certain axolotls have slightly turned-up mouths that also give the impression that they're smiling all the time—but unfortunately for hopeful pet owners, that's not the case and just a matter of appearance.

2. They Are Native to One Place in the World

The axolotl's native habitat is in dire straits. Once found in two high-altitude lakes in Mexico City, these aquatic amphibians are only found in the wild in one location: Lake Xochimilco in southern Mexico City. Their former home, Lake Chalco in central Mexico City, was drained to avoid flooding. Xochimilco has been reduced to a series of canals, and axolotls are scarce due to the loss of its habitat as well as the introduction of predatory carp and tilapia.

3. They Are Carnivorous

Axolotls are carnivorous—they eat everything from fish and worms to insects and crustaceans. They aren’t especially picky and will eat meat that is dead or alive. In captivity, they frequently eat brine shrimp, strips of beef liver, earthworms, fish pellets, and more. Young axolotls, and those with an inadequate food supply, can be cannibalistic, biting off an appendage of a nearby family member. Fortunately, thanks to their ability to regenerate, the injured axolotl can easily grow back the severed body part.

4. They Come in a Variety of Color Patterns

The color pigmentation and patterns of axolotls are the result of four different genes. In the wild, axolotls are most commonly brown or black with specks of gold or olive. Like other salamanders, they can also adjust their color to better camouflage with their surroundings.

The lighter colored axolotls, including albino, leucistic (with reduced pigmentation), and pink, are more common in animals that have been bred in captivity. The feathery gills that line the back of an axolotl's head are also pigmented, most notably in the bright red shade found in albino axolotls.

5. They Can Regenerate Body Parts

A number of amphibians and fish are capable of regenerating tails and limbs, but axolotls take this ability up a notch by regenerating jaws, spinal cords, skin, ovary and lung tissue, and even portions of their hearts and brains. What's more, an axolotl can continue to regenerate throughout its life.

The regenerative abilities of this animal's cells are of significant interest to researchers hoping to translate this ability to humans. This is a remarkable capability: "If an axolotl loses a limb, the appendage will grow back, at just the right size and orientation. Within weeks, the seam between old and new disappears completely."

6. They Have a Large Genome

With 32 billion DNA bases and a genome 10 times the size of a human’s, sequencing the DNA of axolotls is a challenge for scientists. But it's an important one, as it will help researchers discover how the axolotl uses stem cells to regenerate tissue. Scientists have already identified two genes used in regeneration in axolotls. Because the regenerative abilities of axolotls are so impressive, scientists continue to expand their research to include other internal organs and retina regeneration.

Smithsonian describes them as being ubiquitous in research labs—"basically the white mice of amphibians, thanks to their unique genetic profile and their potential to unlock the secrets of evolution and regeneration."

7. Their Courtship Rituals Involve Dancing

When axolotls reach six months of age, it’s time for them to mate. The process begins with the adult animals rubbing each other's cloacal region, and continues with them moving together in a circular, dance-like fashion.

Females lay approximately 100 to 300 eggs and breed once per year in the wild, more frequently in captivity. After the eggs are safely deposited, there is no further parental involvement. When the eggs hatch after 10 to 14 days, the young axolotl are on their own.

8. They Are Critically Endangered

Found only in one small region in Mexico, the axolotl is critically endangered in the wild. They occupy less than four square miles in a habitat that is in severe decline due to development, pollution, and invasive species. Their importance to scientific research and their ability to be bred in captivity should help ensure their survival, but not necessarily in the wild. In 2009, scientists estimated their population had dwindled by 90%. In 2015 they were pronounced extinct in the wild, but then one was found a week later.

The number of axolotls remaining in the wild is uncertain. Conservation efforts have centered on raising the water level of Lake Xochimilco, restoring the axolotls’ environment, and reducing the population of invasive fish species like tilapia and carp (introduced by the Mexican government to improve food insecurity for low-income households) in their habitat.