The axolotl is strictly aquatic. It never leaves the water. It generally evolves by walking or crawling on the ground. Sometimes it rests by floating on the surface or by resting on an element of the scenery or on a plant. It hardly swims, except when, disturbed, a reflex of escape propels it quickly forward by powerful movements of the tail and undulations of the body, the legs tightened along the body. When it uses its air breathing, for example when the water becomes more or too hot, less rich in oxygen, it gains the surface to take a gulp of air. To activate the use of its external gills, it moves them by jerks.
Its sight seems rather reduced, it seeks its food on the ground, with the touch, the smell or the taste thanks to receptors located on the tongue, and in the mouth. Detection is based on the movement of the food or on the smell of the food after the animals have been accustomed to inert food. It occurs only at short distance, a few centimeters.
The capture of the food is a reflex movement of aspiration, violent and not very precise. The animal does not chew, it sucks the whole prey, the teeth are just used to retain the piece of food. Animals that are looking for food typically stand with their heads slightly tilted downwards or obliquely to the ground. Apart from reproduction, and as long as they are too large to be considered as prey, the axolotl shows no interest in its fellow animals, no social activity, no territorial behavior.
However, as the taking of food is a blind reflex, it can happen that it seizes by accident a piece of leg, gill or another part of another axolotl and sometimes tears it off. The damaged part can be reconstituted.
Axolotls have their home in stagnant waters and lakes near Mexico City, so they do not like water flows. They usually stay close to the bottom or directly on the bottom. In a home tank, too, it can usually be observed that axolotls feel most comfortable at the bottom. Axolotl come in multiple types and colors.
As axolotls are nocturnal, many of the animals like to stay somewhat hidden during the day and only come out in the evening.
All about axolotls
Axolotls ( Ambystoma mexicanum ) are caudata amphibians but are often mistakenly thought to be reptiles. They are classified in the family of the mole salamanders ( genus Ambystoma ). Both size and expected lifespan can vary greatly in some cases. As a rule, axolotls grow to between 15 and 30 centimetres ( between 6 and 12 inches ) and weigh between 50 and 300 grams ( between 2 and 10 ounces ). However, there are also specimens that grow up to 40 centimetres ( 16 inches ).
How long does an Axolotl live?
Most axolotls live between ten and twenty years. Occasionally, however, some axolotls have been known to live up to 25 years. Axolotls need cool and oxygen-rich water. They are not solitary animals and should therefore be kept at least in pairs. Many owners decide to keep three animals. These should be about the same size!
Axolotls have external gills, and their lungs are not fully developed. Although they can switch between land and water for short periods, they should spend their lives in water as they are not adult moles but remain in the larval stage. The colder it is, the more often axolotls voluntarily go ashore.
Atl means water and Xolotl stands for monster but is also the name of an Aztec god. Axolotls probably got the name water monster because of their appearance, although nowadays many people find the little amphibians very cute and not monster-like.
Where do Axolotls come from?
Axolotls have their home in Mexico and are not too common in the wild. They lived in Lake Chalco, Lake Xochimilco and a few other bodies of water in Mexico. These are mainly stagnant waters and lakes.
The lakes mentioned are located in a volcanic basin near Mexico City. Today, they are largely dry, and the water bodies are only sparsely developed.
In 1805, Alexander von Humboldt, a German explorer, returned from an expedition in Mexico and brought back two axolotls. He wanted to study them more closely. Many years later, in 1863, a French research team brought a somewhat larger group of axolotls from Mexico to France. Over the years, the little animals were studied more and more intensively before they established themselves much later as popular pets.
Appearance of the Axolotl
The heads of axolotls are rounded and large, their limbs are relatively short. The eyes are wide apart. Behind the eyes they each have three gill branches that can be actively moved. Their tail is flat, has fin seams and is very long. Axolotls use their tail to control their swimming direction. Usually, the males have a slightly longer tail than the females.
What is special about axolotls is that although they grow steadily and also become reproductively mature, they always remain larvae. This peculiarity of axolotls is due to their limited thyroid function – hormones are produced in the thyroid gland of a living creature that are responsible, among other things, for the development of a larvae into an adult.
Axolotls, however, have a malfunctioning thyroid gland, which is why they never become a ‘proper’ adult amphibian. Metamorphosis is therefore not possible for them. Through the external addition of artificial hormones, an axolotl can indeed develop into an adult caudate and then have a similar appearance to a tiger salamander, but this should be avoided.
While an axolotl can live for ten to twenty years as a larva, it can only live for about five years if artificial hormones are administered. Life expectancy is therefore drastically shortened.
The permanent state in the larval stage is called neoteny. Although axolotls always remain larvae, they can of course reproduce.
How can Axolotl regenerate themselves?
Axolotls can regenerate their bodies very well and usually completely, as they are able to regrow their limbs, organs and even brain parts. How this is possible is still not fully understood. Research into the regenerative properties of axolotls is still ongoing.
It is hoped that the research results and findings can also be applied in human medicine. However, some things have already been discovered. Axolotls have connective tissue cells that virtually reverse their development. The special body cells fibroblasts develop again into precursor cells that can form bones as well as skin and tendons.
Thus, the regeneration of different types of connective tissue is possible. However, the adaptation to humans is proving difficult in research – humans also have fibroblasts. In the case of an injury, however, the human fibroblasts do not develop back into precursor cells, but they continue to develop into myofibroblasts – and these form the scar tissue in humans.
The genome of an axolotl is extremely complex. It is ten times as large as the genome of a human, as it has over thirty billion base pairs. Therefore, decoding this genome is not easy. However, it has already been researched that axolotls have some genes that are only found in them and other amphibian species. These genes are active in regenerating tissue.
How does an Axolotl breath?
The axolotl breathes in addition to atmospheric air thanks to a pair of rudimentary lungs, and, like all amphibians, it also breathes through the skin, which is devoid of scales and covered with a protective film, the mucus. It is a vital necessity, we will take care to always maintain an access to the air, notably in the bags of transport. Therefore, the skin is a particularly sensitive organ, exposed to diseases, to the effects of the degradation of the quality of the water etc… and its aspect is a good indicator of health.
The axolotl has four legs each carrying 4 (in front) or 5 clawed fingers (in the back). The sexual and excretory organs, not differentiated externally (the cloaca) are located between the back legs and the birth of the crest. The natural form is pigmented, grey speckled or mottled with black or more rarely brown-beige speckled with dark brown, with a lighter belly.
An adult Axolotl can measure anywhere from six to 18 inches. However, the usual size for this species is only nine inches. As for its weight, the males can weigh about 125 to 135 grams while the females can weigh about 170 to 180 grams – the females are usually bigger than the males.
The head of an Axolotl is wide – much like typical salamanders. Their eyes are lidless (unlike human eyes), so they can’t blink their eyes (this is common in different types of fish as well).
As for their limbs, they have four short legs with long, thin digits. Their digits are what you would call fingers and toes in humans.
The eyes of Axolotls are lidless – they can’t blink their eyes.
Note that the overall shape of the bodies of males and females are also quite different. The females have wider bodies than the males – as the females need space to carry their eggs when they get pregnant. This is also the reason why females are typically bigger and heavier than the males.
Remember their gills? They actually have external and internal gills. They have three pairs of external gills that are located behind their heads – so, there are three on the left side and three on the right side.
Underneath their external gills are gill slits. These gill slits connect with the internal gills of the Axolotl.
Axolotl: Males VS females
Male axolotls usually have a slightly longer tail than females. Males also always have a swollen cloacal region, even outside the breeding season. This is not the case with females. However, the gender can only be determined after about one year, or when they are about twenty centimetres big.
A male reaches reproductive maturity at about one to two years. Females usually become reproductively mature earlier and can reproduce after about one year.
As in many other species, the male performs a “mating dance” at breeding time to “seduce” the female. During the mating dance, the male has his long tail towered, wags it back and forth and also nudges the female to encourage her to mate.
How many eggs can an Axolotl produce?
The females usually produce around 80 to 700 eggs and lay them on water plants. This happens about every two months. The eggs are not always actually fertilised. When fertilised, a small axolotl develops inside the egg – this process is called paedogenesis . Usually, axolotls hatch after about 10 to 20 days. They then feed on the yolk for a few more days.
The babies are already born independently and can move around without any problems. After five weeks they measure about five to six centimeters.
Do Axolotl live together?
As axolotls are not solitary animals, they should be kept at least in pairs.
Of course, if you have only males, egg-laying will never occur. Some owners prefer this.
Axolotls living together should be about the same size so that the larger axolotl does not – voluntarily or involuntarily – attack or try to swallow the smaller axolotl. Smaller axolotls are easily eaten by larger ones. As a worst-case scenario, the smaller axolotl may be even too big to eat and may get stuck in the mouth of the larger axolotl. Both animals can die from this! It is therefore very important that the animals are approximately the same size.