Axolotl Fact File
Credit: Bouboulski, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons
Wild 10-12 years
Captive 25 years
Mexico's Forever Young Amphibian!
The axolotl will spend the majority of its life in its larval form unless exposed to special chemicals which will make them metamorphose.
This species is found exclusively in Mexico. Here they occur in two permanent freshwater lakes, Lake Xochimilco and Lake Chalco, though the population at Lake Chalco is likely extinct.
Females may lay up to a 1,000 eggs in each clutch. Each is individually attached to a plant and covered with a protective jelly coating.
They are threatened through pollution, hunting and draining of the lakes in which they live.
Read on to learn more about these amazing amphibians.
What does the Axolotl look like?
Axolotls spend most of their life in the larval form and have the ability to breed during this stage.
The axolotl has a plump body ending with the long flat tail. Their snout is rounded. On either side of the head is an external gill which consists of three small fingers extending from either side of the head with many small feather like structures coming off this. A fin runs along the back from behind the head to the tip of the tail.
In the wild the most common color variant is black with greenish mottling. Some exhibit silvery highlights.
In captivity they are bred in albino, grey and a mottled white and black variety.
They have a round eye which has a yellow iris. This can be covered by the movable eyelid. They have four legs which are used to carry them along the lake floor but are too small to successfully carry them across land.
On the front foot they have four toes with five present on the back foot.
The entire skeleton of the axolotl is formed from cartilage.
An axolotl may measure 45cm (18in) in length but an average length is typically 22.8 (9in) long. An average axolotl will weigh 56-226g (2-8oz).
How does the Axolotl survive in its habitat?
Axolotls have been popular in medical testing for a long time. They are able to regenerate lost parts of their body up to 5 times. Unlike most animals their body parts regenerate perfectly and takes a few weeks.
Research has shown that the axolotl may be as much as 1,000 times more resistant to cancer than humans.
Their gills allow them to breathe while submerged for life. On occasion they will surface and take a breath.
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What does the Axolotl eat?
Axolotls feed upon a range of worms, molluscs, tadpoles, crustaceans and small fish making them a carnivore. They have been known to cannibalize other axolotls.
They will use suction to hoover up food. This also sucks up small amounts of gravel and this is used to help grind up food in the stomach.
Learn more about the Axolotl in this video from TED-ED on YouTube
Where do you find the Axolotl?
The axolotl is found in only two lakes in Mexico. These are Lake Xochimilco and Lake Chalco. It is believed they are now extinct in Lake Chalco. They could previously have been found in additional lakes connected to these two but it is unclear if this occurred.
Where can the Axolotl survive?
They make their home in two spring fed lakes and are entirely aquatic in their larval form.
Credit: Under License
How does the Axolotl produce its young?
Breeding takes place in their larval form. The breeding season is from March to June in the wild though breeding can occur year round in captivity.
Males and females engage in a courtship display in which they rub and slide against one another while spinning in a circle. At the conclusion of this the male will drop a cone shaped mass that includes the sperm.
The female takes this in her cloaca and uses it to fertilize her eggs. There may be 300-1,000 eggs. Each egg is laid individually on to a plant or rock. Each egg has a protective jelly coating. This method prevents the entire egg mass being taken by a predator and is also needed due to the higher oxygen requirement of each egg.
Incubation is two weeks long. After hatching the young axolotls are on their own with no parental care provided.
Sexual maturity is reached at 6 months old.
What does the Axolotl do during its day?
While they do posses gills they also have well developed lungs and will occasionally come to the surface to breathe. If they spend a long period of time in shallow water they may absorb their gills and begin to breathe entirely using their lungs.
They are solitary and spend most of their day alone.
Most of their life is spent in the larval form though if injected with a hormone in captivity they will metamorphose in to their adult form.
Axolotls are primarily active by night. During the day they will burrow under mud or aquatic vegetation.
When faced with a threat they can move as quick as 15km/h (10mph).
Credit: Under License
Predators and Threats
What stops the Axolotl from surviving and thriving?
Their main predator is large fish. Few of these naturally occur in the lakes they inhabit but many have been introduced leading to them becoming critically endangered.
Humans have had a major impact on their population. The lakes they call home are located close to large human populations leading to increased pollution and hunting.
The axolotl was previously seen as a delicacy by local people but now is legally protected to prevent this.
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The first axolotls used for research were brought to the Jardin Des Plantes in 1860. Almost all laboratory axolotls today can be traced back to the 33 from this import.
They are also known as the ‘Mexican walking fish.’
The name axolotl comes from an Aztec word meaning “water dog.”
This species is believed to have diverged from its closest ancestor just 10,000 years ago.
They are a member of the salamander family.
This species was first described for modern science in 1798.
Credit: Public Domain
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Jackson, T. and Chinery, M., 2012. The illustrated encyclopedia of animals of the world. London: Southwater.
Luis Zambrano, Paola Mosig Reidl, Jeanne McKay, Richard Griffiths, Brad Shaffer, Oscar Flores-Villela, Gabriela Parra-Olea, David Wake. 2010. Ambystoma mexicanum. The IUCN Red List of Threatened Species 2010: e.T1095A3229615. https://dx.doi.org/10.2305/IUCN.UK.2010-2.RLTS.T1095A3229615.en. Downloaded on 10 July 2020.
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