The axolotl is an amphibian whose natural habitat is the lake complex in the area surrounding Mexico City. The original area included Lakes Xochimilco and Chalco, with their canal system, located near the population center known as Tenochtitlán before the arrival of the Spaniards.
The axolotl is considered to be an amphibian of medium size -- between 6 and 12 inches long. The creature is often kept in a freshwater aquarium as an exotic pet. He resembles his relative the tiger salamander, but he never undergoes metapmorphosis, a characteristic called neoteny, so does not outgrow his resemblance to a tadpole. He has feathery gills on both sides of his head. His name, which comes from Nahuatl, the Aztec language, means water monster or water dog.
The axolotl hides under rocks because his body is soft and vulnerable. He is often albino, or pink, but sometimes he has greyish, black or brown shading. He can also be piebald or spotted. He is a carnivore who feeds chiefly on worms and insect larvae. Other options for his diet are small fish or crustaceans. Because he dwells mostly on the bottom of the lake, the axolotl is less visible to predators.
The most common animal predators of the axolotl are birds, including storks and herons. However, the introduction of large fish into the lakes and channels has meant the addition of this natural threat to his survival as well. Species such as tilapia and carp have been introduced so they be a food source for human consumption, but these fish feed on the axolotl.
Unnatural (Human) Predators
Humans are also a menace to axolotls because they capture these curious-looking animals. They catch axolotls in order to put them on display in aquariums, although improper conditions in captivity will cause them to refuse to eat and they will die. Other captors sell them for food. The tradition of using axolotls as food is not new: it stems from the Aztec nation in the pre-Columbian period. Roasted, axolotls are considered a delicacy by modern consumers, although it is becoming harder to find them in Mexican markets. Another way in which humans are a threat to these amphibians is their usefulness in scientific experiments. Axolotls can regenerate body parts, so that what is a survival mechanism for them in the wild has now become a threat to their survival. They are targeted for use by scientists who study them in order to gain a better understanding of evolution.
Axolotls are increasingly endangered; few of these amphibians, which can live up to 15 years, are found in their natural environment in the lake area. The high level of pollution around an ever-growing Mexico City is partially responsible for their diminishing numbers. In 2013 they were found only in Lake Xochimilco, because in the 1970s Lake Chalco was drained in order to avoid flooding. The axolotl is now listed as a protected species and as critically endangered by groups such as the International Union for Conservation of Nature. Fewer than 1,200 are thought to survive in the wild.