As a result, the limbs are underdeveloped; it retains its caudal fin, which originates from behind its large head to the vent. It also keeps the external gills that allow gas exchange and is located behind its head. Such a feature makes the Mexican axolotl a fully aquatic creature, unlike most salamanders.
The appearance of the Mexican axolotl is divided in four categories: black, shades of brown with spots, light pink with black eyes and albino (light pink, golden or tan with pink eyes). While the size varies between 15 and 45 cm (6-18 in), the average length is usually 23 cm (9 in) while 30 cm (12 in) are considered to be rare. Another feature that differentiates them from the Tiger salamander is its long digits.
The eyes of this salamander's species are lidless. Their teeth are very small as they are undeveloped due to the lack of metamorphosis, resulting in the axolotls sucking in their food like a vacuum instead of chewing it.
This salamander species is native to the Lake Xochimilco and Lake Chalco. Unfortunately, Lake Chalco was drained years ago to prevent flooding. And all that remains of Lake Xochimilco is canals, due to the demand from the ever expanding Mexico City and the pollution resulting from it.
Other causes responsible for the rapidly decreasing population of this species in the wilderness are: the introduction of large fish such as the African Tilapia and Asian Carp, the pet trade, being used as laboratory specimens and being sold in food markets. Both the African Tilapia and the Asian Carp have become predators of the Mexican axolotl's young and also share the same food sources. As a result of all these factors, the wild population of this salamander's species belongs to the endangered species list.
The Mexican axolotl reaches sexual maturity between the ages of 18 and 24 months. The sex of the axolotl can be easily distinguished. The male can be recognized by the swollen cloacae lined with papillae, while females have a wider body that can be filled with eggs. The axolotl's body allows the observation of the development of large embryos. In fact, since the development continues without any heart activity until birth, scientists can observe the heart development and the problems linked to the lack of it.
This carnivore's diet is mainly containing the following: wax worms, blood worms, earthworms, small fish, insects, insect larvae, mollusks and crustaceans. Its natural predator is the heron. Its life expectancy in the wilderness varies between 10 and 15 years, although the average is 5 years. In captivity, one specimen lived up to 25 years.
Although most axolotls will not go through metamorphosis, they may be artificially induced through the use of hormonal injections or by diminishing the water level, although most specimens died through this type of experiment. Another special feature studied in a laboratory by numerous scientists is the fact that the Mexican axolotl can easily regenerate limbs and most vital organs within months. They can also accept implants easily and restore their use to full capacity. This special feature is one of the reasons why the Mexican axolotl is the most studied salamander in the world.
The Mexican axolotl is considered to be a culinary delicacy in Mexico and used to be a main food item used by the Aztecs.
As pets, you have to ensure a water temperature ranging between 12 and 20 degrees Celsius (54-68 degrees Fahrenheit) although, temperatures averaging 17 or 18 degrees Celsius (63-64 degrees Fahrenheit) are preferable. Keep in mind that being a poikilothermic organism, its metabolism with reacts to water temperature. Cold water slows its metabolism while warmer water increases the speed of the metabolism, causing stress and increasing this amphibian's appetite.
Using fine sand instead of small gravel is much better since, if swallowed, gravel smaller than the axolotl's mouth can be sucked in and cause the salamander to suffer from impaction in its digestive system, possibly causing death. It is recommended that pet owners put the Mexican axolotl in a 40 L tank and add at least 15 cm (6 in) of water. It is best if no fish are added to the tank as they may nibble on the axolotl's external gills, creating injuries. This type of salamander can feed on salmon and trout pellets, frozen or live bloodworms, wax worms and earthworms and feeder fish.
Chlorine found in tap water is harmful to the axolotl's health. Salts such as Holtfreter's solution are also added to the water of the tank in order to prevent infection.
Let's protect the natural habitat of the Mexican axolotl! Its survival depends on it!
Here are some resources linked to the Mexican axolotl!