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Kingdom: animalia
Branch: chordata
Class: amphibia
Order: caudata
Family: ambystomatidae
Genus: Ambystoma
Species: mexicanum


it is a non-domestic species, not subject to the certificate of capacity, listed in appendix II of CITES. This species has been on the IUCN Red List of Threatened Species since 2008 and some scientists believe that it could disappear in the next few years.
Note that the albino variety (therefore white skin and red eyes) is considered in France as a domestic species (it is only based on the color of the animal, so on the same laying, only albino individuals do not need transfer certificate, other colors, if).

Geographic origin

Ambystoma mexicanum is native to Mexico, more precisely to two lakes, called Xochimilco and Chalco. Unfortunately, with the expansion of cities and the increase of the population, it seems that these lakes are more and more reduced, and are reduced to a few canals. Attempts have been made to reproduce and reintroduce the species in its natural environment but its habitat is shrinking, its near end seems inevitable, and the numbers are more numerous today in captivity than in the wild.


It is a rather nocturnal animal, at least crepuscular and totally aquatic throughout its life. He walks at the bottom of the water more than he swims, so it is necessary to favor the surface on the ground with the height of water. In its natural environment, it lives in lakes of calm (no current) and cold water (the water rarely exceeds 20 ° C and can drop to 6 ° C, or even less).


The axolotl is a neotenic salamander, that is to say that it remains all its life in the larval state, retains its gills and therefore never comes out of the water. The gills are external and there are 3 on each side of the head. At birth, it measures about 8 mm, reaching an average of 25/30 cm in adulthood, knowing that some reach 40cm. It is a nocturnal animal and not very moving in general. Exclusively aquatic, it combines three types of breathing: through the skin, through the gills, and through rudimentary lungs (which explains why it regularly rises to the surface to inhale air). The first peculiarity of axolotls is neotenia. This means that this salamander retains its juvenile characteristics (outer gills, caudal veil, webbed fingers and absence of eyelids) at its adult size. More importantly, it can reproduce in this larval state once it reaches adult size. Only one other species of the genus also has this ability, it is Ambystoma andersoni, which is much more active, was born and feeds in a less protein way. and should not be hybridized with ambystoma mexicanum to avoid loss of the species.

This neotenia is due to the development of an atrophied thyroid gland and therefore to the absence of a hormone interacting with growth hormones, thyroxine. The first hypothesis concerning the atrophy of this gland wants that the cold temperatures of their environment of origin disadvantage the more fragile terrestrial form. Because axolotl can under certain conditions (increase in temperature, decrease in water level, and above all external contribution of thyroxine) override neotenia and transform to reach an adult stage of life on earth. It then loses its juvenile characteristics and develops lungs and eyelids to physically approximate the rest of the species of its genus. Its biology also changes dramatically, because even if it now lives in wetlands, it becomes strictly terrestrial, see burrower. It was also long believed that Ambystoma tigrinum was the adult form of Ambystoma mexicanum.

It has very visible costal furrows in adulthood, kinds of hollows, along the sides.
It has 4 toes on the front legs and 5 on the back legs.
Its natural color is more or less dark brown. In captivity, different colors are obtained including albino (white skin, red eyes), depigmented (white skin, black eyes), golden (more or less golden skin, red eyes), and other colors such as piebald (harlequin), the copper color created in the USA and imported into Europe which, on the other hand, comes from a single strain, we isolated on one side the strong and larger individuals and on the other the weaker and smaller (the latter more prone to various diseases). New colors appear little by little. And also more and more mosaics, which seems logical given the increasing number of individuals in our aquariums.
Its average lifespan is 15 to 20 years.

Particularities of the species

As already discussed, this species is neotenic, it has gradually lost the ability to pass from the larval state to the terrestrial state, since it no longer has the utility in nature. Other species such as Ambystoma tigrinum can also be neotenic on occasion, when outside conditions do not allow them to come out of the water, but most of them are not. In axolotl, a lack of iodine produced by the thyroid means that the animal is very rarely able to pass to the terrestrial phase. Stimulation of the thyroid by injection of iodine or thyroxine (thyroid hormone) can artificially cause the transformation. In this earthly form, it survives on average only 3 to 5 years (when it does not succumb to this metamorphosis).

Its second characteristic, for which it has been studied extensively in the laboratory, is its great capacity for regeneration. Indeed, in the event of loss of a limb, this one pushes back in a few weeks, whatever the age of the animal (even if it seems that it is faster in a young individual). This regrowth has also been observed in scientific studies of the tail, gills, lips, and even parts of the brain and spine. This is why this species is much studied in order to understand this regenerative capacity with the aim of applying it to human medicine.


Since it spends its life in water, the axolotl must be kept in an aquarium (and not a vivarium!). For a couple, a 160 liter aquarium is suitable but this is a minimum, it is better to have more space for our kitties than less. The axolotl is relatively territorial and the aquarium will therefore have to be large enough if you want to have several individuals live together without there being "small disputes".
It is a bottom animal, the ground surface of the aquarium is therefore more important than the height of the water (which must nevertheless be at least the length of the body of the animal as well as 10 to 15 cm of margin for the jumping axos). The aquarium must contain real plants (waterweed, vallisnerias, microsorum, anubia, etc. you can consult a list of these plants in the maintenance section) (Note that the axolotl can also play bulldozers and uproot plants), hiding places to his size (at least one per individual), a substrate (fine sand) and a thermometer to monitor the temperature of the water.

Filtration is important because axolotl produces a lot of waste. However, it is an animal of stagnant water originally, this is no longer the case but it does not like excessive currents, and too powerful a filter will produce it and may stress the animal to the point of it. cause long-term illness. The filter jet must therefore be "broken". The plants will help keep the water clean by partially filtering the waste produced.
The water used can be that from the tap, which has been left to stand for 24 to 48 hours to allow the evaporation of the chlorine (which destroys the good bacteria in the aquarium).
You can also use rainwater, collected for example in a plastic container (if it is too soft KH too low place a limestone there). Avoid water that has leaked into zinc gutters as water can be made toxic by this metal.

As with any aquarium setup, you must respect the nitrogen cycle before putting the kitties in the aquarium, which usually takes between 4 and 5 weeks.

cycle azote aquarium axolotl

Lighting is not necessary for the axolotl, it will stress it if it is too powerful but essential for the plants which participate in a good oxygenation of the water as well as an elimination of nitrates, and are very aesthetic. If you think that your axolotl is stressed by too much light, you can add floating plants to its aquarium (Vallisneria or waterweed can grow to the point of partially covering the surface of the water, or surface plants such as than Pistia Stratiotes or duckweed used by some to cover the surface of your water very quickly). But let's put into perspective our axolotls are now in clear water and no longer have their feet in the mud, they are perfectly suited to life in lighted aquariums now.

vallisnerias, plantes avec axolotls
axolotls, lentilles d'eau

The question of whether or not to put a bubbler? It all depends some axolotls will be strongly stressed by it others not for you to see with yours (knowing that the benefit is mainly visual the best way to have oxygenated water is to maintain a certain quantity of plants and to pump outlet nozzle to obtain a small swirl which helps to promote gas exchange).


Axolotl lives at room temperature and does not require heating. A temperature of 16 to 18 ° C is perfect, above, the axolotl will be stressed and will be at risk of contracting diseases. The water should especially not exceed 22/23 ° C because this would put the life of the animal in danger. Do not be afraid if the temperature of your water drops, the axolotl is not afraid of cold water on the contrary. The water can drop to 10 ° C without any discomfort for axolotls (remember that their natural habitat is in cold mountain waters). Aquarium neon produces heat and therefore increases the temperature of the water. Prefer the led lighting as much as possible (between 6000 and 7000 k to obtain the solar spectrum is: cold white not less not more (risk of algae) and the intensity in lumens will vary according to the depth and width of the tray 850 lumens will be sufficient on a small portion 50 cm wide with 40 cm high but it will need at least 1300 lumens on a height of 50 cm by 50 cm wide.You choose bulbs or ramps.

In addition to this, you will need to know more about it.


Axolotl can coexist with certain fish that can live in cold water. The goldfish cannot coexist with an axolotl because it would attack its gills which it would take for bloodworms. On the other hand, we can easily make the axolotl "coexist" with small fish such as guppies, or platties, knowing that they will be used from time to time as a meal (therefore personal choice) if you incorporate fish, however, be careful. to have observed a quarantine of at least 15 days if they come from a pet store, the risk of parasitization for the axolotl is suddenly higher with this type of cohabitation.

In addition to this, you will need to know more about it.


The axolotl is not the most difficult to feed. It can feed on earthworms, (found in fishing stores or quite simply in the garden but nowadays be careful with the pollution of our land, personally I do not use, moreover some axolotls digest them very badly), (mealworms are to be avoided unless they crush their heads because they have small sharp teeth capable of causing lesions in the stomach of your axolotl but the chitin they contain remains a little indigestible), bloodworms (alive or frozen for young axolotls because past their 10 cms this does not meet the complete needs of axos), pieces of freshwater fish or pieces of beef heart (the latter rather in the case of a convalescence or reconstruction legs, etc. because it is more difficult to digest). The food should be the size of the axolotl's mouth because it does not chew. It can be given with pliers, or deposited at the bottom. We can indeed accustom the axolotls to eat at the bottom by always placing the food in the same place. Today there are pellets specially designed for axolotls, sold in specialized pet stores which contain all the elements necessary for a balanced diet and allow the other foods mentioned above to be given only “extra”. The calcium contained in these pellets stimulates the intestinal system (avoiding constipation which could lead to infections, prolapse, etc.) and the necessary vitamins. Young axolotls should be fed every day. When they reach 15 cm, they can be fed every 2-3 days. You will see if an axolotl is hungry when it moves around the aquarium a lot. The axolotl is a rather greedy animal but which (as a general rule) knows how to regulate its food consumption itself. Be careful not to overfeed your adult axolotl as some people are prone to obesity. The principle is therefore to feed 1 to 2 times a week, and at each feeding we give until the animal refuses (my adults only ask once a week), the hotter the water, the more the axolotls are hungry.


The axolotl is easy to reproduce, with or without stimulation. First, sexual maturity can be seen on light-colored axolotls by the fingertips turning black. Conversely, in dark-colored individuals, the fingertips are lighter. This maturity occurs early in the development of the axolotl, after about 6 months to a year, but it is better to wait until they have reached their adult size, or at least reached 20 cm, before reproducing them. To distinguish the sexes, it seems that the female is overall rounder than the male, with a proportionally shorter tail, but these criteria are quite difficult to observe. The most obvious clue is at the level of the cloaca, which is more swollen in the male than in the female.

axolotl femelle


axolotl male


male femelle axolotls

To stimulate reproduction, some lower the temperature to between 10 and 15 ° C for a few weeks. During this phase, we can separate the individuals but it is not essential. Some only separate their couples without lowering the temperatures. In others, even without any stimulation except the natural reduction in day length, and a natural lowering of temperature, axolotls recurred. Rather, the breeding season takes place from early winter through spring, but breeding can be initiated almost anytime. In some years, axolotls can lay up to 6 or 7 eggs. To reproduce, the male deposits one or more spermatophores (a kind of gelatinous cone with the sperm at the top) at the bottom of the water, and directs the female to suck it in with her cloaca. The spermatophore.

spermtophore, axolotl

The eggs are therefore fertilized in the abdomen of the female. The female then lays her eggs one by one by sticking them in the plants and on the decoration of the aquarium. She can lay between 50 and 500 eggs in one lay. On average, a laying revolves around a hundred eggs. Note that the eggs are the color of the female who lays them. The color of the young will appear as the embryos develop.

axolotls, oeufs, ponte
oeufs axolotls blancs

In addition to this, you will need to know more about it.

The eggs are round, transparent with the embryo in the center. We can also observe its evolution by transparency. The eggs develop and hatch in one to two weeks, depending mainly on the water temperature. The eggs must be separated from the adults as they will be devoured (the eggs or the young when they hatch). We place the eggs in a tray (with the plants because trying to take them off would damage them) with a bubbler preferably because they need well aerated water.

When hatching, the young have their yolk sac to absorb, so we do not feed them during the first two days, the time of their absorption. The young are very hungry, so be aware that there will be losses during group breeding. This can be avoided by raising the little ones individually, but it takes a lot more time.

The young will initially be fed live prey the size of their mouths (they are only stimulated the first few weeks by the movement of their food and therefore do not accept inert food). Artemia nauplii are very suitable. Artemia breeding kits are sold in pet stores.
The young axolotls grow quite slowly, once they measure 2 or 3 cm (at the exit of the front legs), we will be able to feed them with thawed bloodworms. At this size, we feed them every day.
Once they have reached ten centimeters, we can feed them every two days, switching to a richer and more nutritious food, such as pellets. Some will still claim every day, each his own pace, our axos are all different.
When acquiring axolotls, be careful not to mix animals of too different sizes.

Illnesses (More details in the health and hospital section)

As young people are particularly voracious, it often happens that animals are missing a limb. Do not panic, it grows back very well in a few weeks, you just have to watch for the appearance of an infection or a yeast infection.
Infection: presents as blackening or loss of injured areas. Treat with an aquarist antibacterial, following the instructions. Do not use any product containing malachite green, which is toxic to amphibians. Methylene blue can also be used in a bath, at a rate of 2 to 4 mg of product per liter of water (see methylene blue sheet to avoid dosing errors).
Mycosis: appears in the form of a kind of cottony cloud on the skin of the animal. To be treated with an aquarist antifungal if the case is very severe otherwise salt bath without iodine (see disease and care sheets).

Flotation : the animal floats on the surface and fails to return to the bottom despite its attempts. This situation is due to a stress of which the origin can be very diverse: current due to a too powerful filter, nervous fish which disturb them, bubbler, noise, too few hiding places, not enough plants, bad water quality. , excess food, occlusion, too much lighting, overcrowding, etc. The stress inflicted on the axolotl causes it to float and the stress to float, so this vicious circle must be broken. The solution is simple, just isolate the animal in a tank of fresh water (the ideal being 10-15 ° C) with just enough water so that its legs touch the bottom. It should be left in this tank for a few days without feeding it because it would float again. It is then necessary to determine the origin of the stress before reintegrating it in its usual baccalaureate to avoid a relapse. In most cases the serene adult axolotls do not float but if it does happen and you have enough plants for them to cling to it you might as well prefer this natural solution to additional stress by isolating it. "NO TO TUPP BAC / FOR NOTHING!"

When buying, an axolotl is not very expensive, between 10 euros and 35 euros depending on whether it is in a private or in a pet store. The most expensive purchase is the aquarium, at least 160 liters for a couple, but there are good opportunities on the net. You then have to buy a filter (3 times the flow rate of the tank capacity for a 200 liter tank 200 x 3 = 600 l / h for the pump) and plants. It is not a very expensive animal to maintain, since it does not require heating and its food can be purchased in pet stores and fishmongers. A sheet is available with the foods that you can give to your loulou.

In short
If you take the trouble to give it the place it needs, the axolotl is a very pleasant animal to observe that is not afraid to show itself as soon as the conditions are right. It makes an impression, pleases or displeases just as much, but it never leaves people indifferent.

interdits axolotls, iode, cuivre, galets, quartz
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