Facts about Axolotl

21 Axolotl facts

Ambystoma mexicanum

They are very distinctive animals with unusual characteristics. In nature, despite never reaching an adult form, they are capable of reproduction. Remaining in the larval stage all their lives, they retain many breathtaking characteristics, causing envy among other living organisms. They are eagerly studied by scientists trying to learn about their fascinating regenerative abilities. Since breeding axolotls is quite simple, they can often be found in home aquariums.
The axolotl is an amphibian of the Ambystomatidae family.
This family contains more than 30 species of amphibians: Ambystoma – 32 species, and Dicamptodon – 4 species.
The axolotl is native to Lake Xochimilco and Lake Chalco in the Valle de México, Mexico City.
Today, axolotls can be found only in the southern parts of Lake Xochimilco since Lake Chalco was artificially drained in the late 1860s to prevent flooding.
It is closely related to the tiger salamander, an amphibian native to North America.
Unlike its cousin, however, the axolotl, lacking thyroid-stimulating hormone, never leaves the aquatic environment unless it is artificially stimulated to undergo metamorphosis with exposure to appropriate hormones.
Their size ranges from 15 to 45 centimeters, although they rarely exceed 30 centimeters in length.
Axolotls stay primarily at the bottom of the lake.
When kept in captivity, they can suck the substrate from the aquarium along with their food, which can cause severe problems with their digestive system. Therefore, it is valid not to fill the aquarium with gravel but with sand grains not exceeding 1 mm. It is also not recommended to place objects with a diameter of fewer than 3 centimeters, which axolotl can easily swallow. Ingested stones and gravel are prevalent causes of death.
Axolotls do not transform into adults.
It is due to the lack of thyrotropin, a hormone necessary for the thyroid gland to produce hormones allowing metamorphosis.
The most interesting phenomenon associated with the axolotl is neoteny.
It means acquiring sexual maturity without undergoing metamorphosis. Wild axolotls do not outgrow the juvenile stage; they remain in the aquatic environment and retain their gills.
Axolotls reach sexual maturity usually at a year old.
Axolotls spawning season is in February.
Females can lay up to thousand eggs that hatch within two or three weeks. "Parents" do not tend to their offspring.
Axolotl's eyes are lidless.
It is because eyelids are developed during metamorphosis. This process allows amphibians to adapt to a terrestrial lifestyle.
Axolotls that undergo metamorphosis change their physiology.
Metamorphosis allows axolotls to adapt to terrestrial conditions. They develop eyelids, muscle tone increases, gills disappear, and skin becomes more impermeable to water. Lungs, present in larval form, develop into vestigial form. Axolotls that undergo metamorphosis resemble salamanders of the Ambystoma velasci species, although growing longer fingers.
Axolotls are carnivorous.
They feed on mollusks, insects, arthropods, and small fish. They locate their prey using their sense of smell, and since having vestigial teeth, their primary feeding method is suctioning.
Axolotls can often be cannibalistic.
Cannibalism is widely observed shortly after hatching since larvae are voracious and require frequent feeding. In addition, axolotls kept in groups can bite each other's limbs and tail fins.
Axolotls have unique regenerative mechanisms.
Their wounds heal, and they can also regenerate their limbs, tails, fragments of the central nervous system, eye tissue, heart muscle and some parts of their brain.
They can have organs transplanted from other individuals.
There are known cases when eyes or parts of the brain were transplanted from another axolotl, regenerating and gaining full functionality.
The axolotl genome is approximately ten times longer than the human genome.
It is the second longest in the animal kingdom.
Axolotls were one of the pillars of the Aztecs' daily diet.
Given that the Aztec civilization fed on everything that lived, it is easy to imagine that axolotls were common prey for fishermen.
The species is critically threatened with extinction.
Currently, the number of wild individuals ranges from 500 to 1,000. It is mainly due to the increasing urbanization of the Mexico City area, water pollution, and the introduction of Tilapia and Perch fish – warm water species known for being invasive. They prey on young axolotls, reducing their population.
In 1998, 6,000 individuals could be found per square kilometer of Lake Xochimilco.
In 2008 the number dropped to 100, and since 2013 no specimens have been found. Soon, axolotls may disappear from their natural environment entirely.
Despite a drastic decline in the wild population, axolotls are unlikely to become extinct.
They are popular additions to house aquariums, where breeding is relatively easy – all that is needed is a 150-liter freshwater aquarium planted with vegetation. Axolotls will thrive undisturbed and reproduce quickly.
On October 2021, the Bank of Mexico introduced a new 50-peso note containing the image of an axolotl.
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