The axolotl ( Ambystoma mexicanum ) is one of the most fascinating and unique amphibians in the animal kingdom due to its amazing abilities and characteristics. Since its discovery 150 years ago, it has captured the attention of scientists and wildlife enthusiasts because of its unusual capacity to regenerate body parts and its neotenic behavior, maintaining a juvenile appearance throughout its adult life.
The axolotl is a species endemic to the lakes of Xochimilco , in Mexico City, and despite its popularity in captivity, wild populations are critically endangered. In this article, we will discuss in detail the physical and biological characteristics of the axolotl, its habitat, diet, and reproduction , as well as some interesting facts that make this animal a unique and amazing species.
Main characteristics of the axolotl
Scientifically known as Ambystoma mexicanum , the axolotl is famous for its regenerative abilities , which allow it to rebuild limbs, its tail, and even vital organs such as the brain and heart. This astonishing power not only sparks interest in the scientific community but also opens a window for medical research into cell regeneration and the repair of human tissues.
One of the axolotl's most peculiar characteristics is its neoteny , meaning it reaches sexual maturity without undergoing complete metamorphosis. Unlike most salamanders, which undergo transformations that allow them to live on land, the axolotl retains larval characteristics such as external gills and its entirely aquatic lifestyle.
The axolotl can measure between 15 and 30 cm in length and weigh between 60 and 230 grams. There are various pigmentations: ranging from brown and gray to the very distinctive albino with white skin and reddish eyes. Mutations exist that give them particular colors, such as the golden albino or the leucistic, which displays pink skin with black eyes.
Physical description of the axolotl
The axolotl has a wide, flat head with small, lidless eyes. Its large mouth gives it a "smiling" appearance, a characteristic that makes this species particularly striking. On either side of its head, the axolotl has three pairs of feathery external gills that allow it to breathe underwater and give it a very distinctive look.
In addition to gills, the axolotl can breathe through its lungs and skin , a trait shared by other amphibian species. Its body is slender and long, with a laterally flattened tail that it uses for swimming, giving it greater agility in the water. Although it has slender limbs, they are not developed enough for walking on land.
Axolotls in the wild tend to be dark, such as brown or black, which provides them with natural camouflage in their aquatic environment. In captivity, however, albino and leucistic varieties are bred, whose lighter shades make them popular as pets.
Habitat and distribution of the axolotl
The axolotl is a species endemic to Mexico , historically inhabiting the basins of Lakes Xochimilco and Chalco. However, due to the urbanization of Mexico City, lake pollution, and the introduction of exotic species such as tilapia and carp, its populations have declined drastically, and today it can only be found in the canals of Xochimilco.
Axolotls prefer fresh, cool, well-oxygenated waters with temperatures ranging from 10 to 20 degrees Celsius. Their environment should contain abundant aquatic vegetation, which not only provides them with shelter from predators, but also serves as a safe platform where they lay their eggs.
In captivity, the axolotl can survive as long as very specific conditions are maintained in its aquatic environment. It is vital that the water is free of contaminants such as chlorine and ammonia, which can be lethal to these amphibians.
Axolotl feeding
The axolotl is a strictly nocturnal carnivore . In the wild, it feeds on small fish, aquatic insects, mosquito larvae, crustaceans, and small invertebrates. Since it lacks true teeth, the axolotl uses its mouth to suck in its food, swallowing prey whole and then digesting it in its digestive tract.
In captivity, their diet may include worms, small pieces of meat such as chicken or fish, as well as other live foods such as insect larvae and shrimp. It is essential to avoid excess food in their diet, as overfeeding can lead to obesity and worsen the quality of the water in which they live.
Juveniles feed more frequently than adults, meaning young axolotls should be fed daily, while adults can be fed 2-4 times per week.
Reproduction of the axolotl
The axolotl's reproductive process is as unique as its biology. Axolotls reach sexual maturity at 12-18 months , although they never undergo metamorphosis, meaning they reproduce while retaining their larval characteristics. This distinctive trait is one of the clearest manifestations of neoteny in this species.
The male's courtship involves a dance in which they use rapid movements of the tail to attract the attention of the female. During copulation, the male deposits packets of sperm on the lake bed, known as spermatophores, which the female collects with her cloaca to fertilise her eggs internally.
The female can lay between 200 and 300 eggs, which are attached to surfaces in the water, such as aquatic vegetation or rocks. In approximately 14 days, the eggs hatch and the young emerge with a larval appearance, fully ready to begin their aquatic life and feed themselves, although their survival rate in the wild is quite low due to the presence of predators such as introduced fish.
The reproductive cycle of the axolotl has been the subject of study due to its neoteny and regenerative capacity, and significant efforts are currently being made to encourage captive breeding and safeguard this species. However, the situation of the axolotl in the wild remains critical due to pollution and habitat loss.
The axolotl represents much more than an animal with fascinating qualities. This small amphibian has had a profound impact on modern science, particularly in studies on cellular regeneration, and its extinction would mean the loss of an invaluable opportunity for scientific learning. In addition, it is a culturally significant animal for Mexico, always represented in local mythology and legends.