Whether you’re brand new to owning an axolotl (ambystoma mexicanum) or you’re a seasoned veteran that has kept the “Peter Pan of amphibians” for many years, you may not know all of these amazing facts. Though they have been around for thousands of years, we are still learning more and more about these fascinating amphibians.
Keep reading as we go over 21 fascinating facts about axolotls. Go ahead and keep track of what you already knew compared to new things you learned here and let us know in the comments below.
Table of Contents
Fun Facts Axolotl Facts
1. Their Numbers Are Higher in Captivity Than in the Wild
Axolotls are considered critically endangered and hanging on the cusp of extinction in the wild. According to the National Geographic Society, there may only be between 50 to 1000 axolotls left in the wild as of 2019.
Their natural habitat is located in a small lake near Mexico City called Xochimilco. They are used to high elevation, cool, clean, glacier-fed waters but because of pollution, overfishing, and the introduction of invasive species, their natural numbers have rapidly declined.
Fast-growing, indiscriminate feeders like tilapia and carp are not native to these waters so they have few if any natural predators to keep their numbers in check. With nothing to control populations, they have taken to eating axolotls, their eggs, and babies.
Unchecked pollution has had detrimental effects on axolotl populations as well. Clean water is imperative for these little amphibians, and the dirty water that has clouded the habitat also leads to their decline.
It’s estimated there are over 1 million axolotls located in labs and home aquariums across the world. Unfortunately, the axolotls in captivity are not pure axolotls and can’t be reintroduced into the wild.
Scientists are unsure what the effects on the environment could create.
2. Axolotls on the Menu?
Did you know that in some areas of the world axolotls are considered a delicacy? In their native habitat before they became so endangered and protected, the citizens located around Lake Xochimilco would routinely eat the little amphibians.
Axolotl tamales were a regular occurrence. They were wrapped in cornmeal, covered in corn husks then steamed whole. In the late 1700s, people commented that axolotl tamales tasted very similar to eel dishes.
Today, because of breeding, you can get them deep fried in a special restaurant in Osaka, Japan. Patrons there liken their taste to crunchy whitefish. Personally, I think I’ll pass, they’re just too darn cute to eat.
3. Axolotls Are Only Found in One Place in the World
Once, hundreds of years ago axolotls could be found in a couple of high-altitude lakes in Mexico, but recently they can only be found in Lake Xochimilco, and in extremely rare numbers. Most of the other lakes have dried up or been taken over by overdevelopment.
Their closest relative is the fire salamander, but axolotls never morph out of their juvenile state and move to live on land.
4. From Lab Rat to Lab ‘Lotl
Scientists have been experimenting on little axies for over 150 years. They were transported from Mexico to Paris where they were a novelty for higher society. From there, they moved to labs because of their strange appearance, and have been a staple in many laboratories since.
Scientists were first interested in their resistance to “growing up.” They remained in the adolescent stage and never morphed like most other amphibians. Then when scientists realized how strong the regenerative properties were, they started looking into stem cell and regeneration studies.
The largest axolotl laboratory is at the University of Kentucky in Lexington.
5. Your Axie Probably Had Its Genes Spliced
The axolotl in your tank or the one you are thinking about buying is not the same as wild axolotls. Chances are, if you could track down its genetic lineage, it would probably originate from a lab.
Early in the experiments, axolotl genes were spliced with those of salamanders to test regeneration capabilities.
Some have even been spliced with jellyfish DNA. If you have seen or heard of axolotl morphs called Green Fluorescing Protein or Red Fluorescing Protein (GFP and RFP respectively) they will glow green or red under ultraviolet light.
They are rare morphs that will cost you more money to own, but they get their glowing skin color from the DNA of jellyfish.
6. Axolotls Are Becoming Inbred
Most of the axolotls in labs today came from a Polish lab back in 1935. Many of the axolotls in aquariums and shops came from those same labs.
In fact, the breeding stock became so closely related that scientists began introducing fire salamander DNA to axolotls to widen the diversity. Today, most axolotls have salamander genes and can actually breed with wild salamanders.
At one time scientists also introduced more wild axolotls to the breeding group to keep them from becoming so inbred. Because of the close breeding, some labs began getting groups of baby axolotls that would die off soon mysteriously or have odd anomalies like extra digits.
The axolotls you’re breeding or planning to breed could be second or third cousins. If you do plan on breeding axolotls, try to get males and females from different aquariums or breeders to reduce the chance of inbreeding.
7. They Can Regenerate Like Wolverine
One of the reasons scientists are so interested in axolotls is because of their amazing regenerative capabilities. You may have even noticed their gills regenerating in your aquarium.
Sometimes axolotls in the same tank can get grumpy and attack the other, often seeing damage to the sensitive gills. Fish will also pick at them, thinking they are little worms. But the gills will often regrow.
Scientists take this regenerative capability to the max though. Some reports say they can regenerate whole limbs up to five times before they start growing back deformed. Others say they can regenerate the same tissue, including bones, hundreds of times.
Their regeneration is so complete that there isn’t even a scar. The skin comes back flawlessly.
They can even regenerate internal organ tissue like the liver, heart, lung, (not a typo, we’ll get into that in a minute), and parts of the brain. Their regenerative powers can even grow back parts of their spinal cord whether it’s been crushed or severed, it grows back.
8. Cancer Resistant
It may have to do with their mutant-like regenerating abilities, but axolotls are very resistant to cancer. It’s suggested that these little amphibians are somewhere in the neighborhood of over 1000 times more resistant to cancer than mammals.
Scientists are not sure what makes them so resistant to this terrible affliction, but they think it may have to do with the way the cells are able to regenerate so well. It’s like the cells are able to “push out” stem cells which are the building blocks of organs and tissue.
So, much like sharks and Deadpool, your axie really never has to worry about meeting “El Cancer,” the big C.
9. Axolotls Can Breathe Air
Not only can they breathe through their external gills, something that is nearly unique to axolotls, but they also have rudimentary lungs. While observing them, you may even see yours swim up to the top of the tank and take a gulp of air.
It may look like she is going up to snap at something floating on the surface, but really, she is grabbing a gulp of air. As long as there is enough oxygen in the water you don’t have to worry about this behavior. Sometimes they seem to simply want to get a gulp of air because they can.
If your axolotl is seen going to the surface on a regular basis or pretty frequently, you may not have enough oxygen in the water. You may have to add a bubbler or lower the temperature of the water.
Cooler water holds onto oxygen better than warm water.
10. Axolotls Never Grow Up
All amphibians go through a metamorphosis. They start out as eggs, usually covered in a jelly-like protective covering, then they live in the water for their developmental, juvenile time. Think back to grade school when they showed you the lifecycle of frogs.
They live in the water as tadpoles, but then they begin to grow tiny legs, their tails shorten and eventually disappear, and their gills are replaced by lungs. When that happens, the frogs move onto the land. They have to stay near the water and still jump in for protection, but they can survive on land.
Axolotls never lose their gills, their tails, or move to dry land. They stay perpetually juveniles. This trait of not morphing to the adult phase is called a neotenic trait.
While they can come out of the water for short periods, this isn’t a recommended practice. Axolotls really should spend their lives in water.
11. Gravel Helps Digest Food
Axolotls don’t have well-developed teeth and cannot chew their food. They swallow everything whole. Since they are carnivores, sometimes they will swallow small pieces of gravel to help digest their food, much like a chicken does.
Unlike chickens though, they don’t have gizzards. Because of this trait, many axolotl owners only use fine sand, or no substrate at all when they set up their axolotl aquariums.
Large pieces of gravel will probably end up getting swallowed. This can lead to impactions or other gastrointestinal problems, so when setting up an axolotl tank you should use fine aquarium sand or gravel that is bigger than the axie’s head.
12. Named After an Aztec God
Xolotl in Aztec mythology is the god of fire, deformities, twins, disease, and death.
He is portrayed as a black dog and was said to help guide souls through the various levels of hell. He is the twin brother of the more famous Aztec god Quetzalcoatl.
Xolotl was a master of disguise and could transform into nearly any shape. In the legend, the axolotl came about when the gods created humans and the sun. The gods wanted the sun to move around the earth but couldn’t move without sustenance.
This meant there needed to be a sacrifice. Xolotl was to be the sacrifice so the sun and moon could move around in the sky. Obviously, Xolotl didn’t want to be a sacrifice, so he transformed himself into the amphibian, axolotl, and hid out in a lake.
Soon the wind god found Xolotl, and he sacrificed anyway so the sun and moon could travel across the sky. But we still got the axolotl after all.
13. A Lot of ‘Lotl Eggs
A female can have eggs in her body and hold onto them while waiting for a male to fertilize them. If these eggs are not fertilized in time, they can be reabsorbed into her body. This can happen over and over.
But when her eggs are fertilized, she can lay a lot of them. Axolotls can lay anywhere between a couple of hundred eggs up to 1500.
When she starts to lay them, she will deposit them on plants—whether they are real or artificial it doesn’t matter—on aquarium decor or pumps. The female is really looking for water currents.
She wants to find a gentle current that will wash fresh water over the eggs so they can exchange gasses. A current that is too strong can damage the eggs or knock them loose and then they can get sucked into the pump.
The eggs are tiny and covered in protective jelly. Soon they will start to develop into baby axies and start hatching.
When babies are first born, they can’t smell much and rely on sight to catch prey. That’s why they need such small, wiggling prey like brine shrimp and daphnia when they start eating.
14. Came to American Labs in 1935
People knew about axolotls for a long time before they came to America. People of Mexico City were fishing for them and eating them for hundreds of years before people came from Europe and took the axolotl across the Atlantic.
There was a bit of a breeding craze sweeping across Europe in the 1900s. Naturalists, museums, and private aquariums all wanted to get their hands on the exotic axolotl.
Scientists also took note and eventually the axolotl made its way from a Polish lab all the way to the University of Buffalo in New York. From there they went to the University of Kentucky and beyond.
Now they are found in labs across the United States and in private aquariums everywhere.
15. Axolotls Only Have a Few Natural Colorations
Through selective breeding, adding different DNA, or transplanting, there are now approximately 20 different axolotl morphs (color variations). They can come in various colors from blue, green, white, pink, green, brown, black, and more as well as a mixture of all of these colors.
Some can even have different colored tails like the firefly morph, while still, some look like they were split down the middle and combined with another, but in the wild, there are only a few colors.
Wild axolotls are typically olive green, brown, or other drab, dark colors with a lighter belly and underside. This is so they can camouflage among the vegetation in their natural habitat.
16. Cannibalistic Axies
Axolotls are carnivores. They will eat fish, worms, insects, mollusks, and basically any living thing they can stick into their mouths. Whether this will harm them or not doesn’t seem to phase the axolotls as long as they think they can swallow it.
This tends to get them in trouble sometimes, as I’ve heard from several people who had to remove different things from their mouths.
This trait of trying to eat anything that moves means that their offspring or other axolotls are not exempt from getting eaten. If you are new to breeding, you will have to move the adults away from the eggs or vice versa after the female has finished laying.
It’s not uncommon for females to lay their eggs, then turn around and start snacking on them later on. Whether they have forgotten they spent all that time laying them or their hunger pangs are simply too strong to ignore, I can’t say.
This behavior is also seen in juveniles, especially if they start to feel crowded. They will start to eat each other when they start getting a little older and if they feel like they don’t have enough space.
17. Axolotls Can Be Forced to Grow Up
These perpetual teenagers can be forced to grow up and morph into an adult stage. Scientists have found out that giving them a shot of iodine will start maturation in axolotls. The iodine is injected into the thyroid which in turn is like giving them a huge dose of hormones.
Basically, it’s like Mom and Dad finally standing up and telling them to go out, get a job, and start living on their own. The axolotls end up losing their gills and looking a lot like their tiger salamander relatives except they tend to have slightly longer toes.
The unfortunate downside to forcing the axolotls to finally grow up, is their lives are drastically shortened. Maybe it’s the shock of seeing the “real world” for the first time that sends them into an early grave. Sometimes I wish I was a kid again—often on a daily basis.
It seems nature has left these unique creatures perpetual juveniles for a reason. They aren’t meant to grow up, and when they are forced to become adults, their regenerative abilities are greatly diminished.
18. Organ Donor Masters
Probably because of their incredible regenerative abilities, axolotls readily accept organ transplants.
Unlike humans and mammals, who have to have exact matches, and then they have to remain on anti-rejection medication for the rest of their lives. Still then, even after years, the body can suddenly reject the donated organ.
Axolotls don’t seem to have that problem at all. Scientists have transplanted all types of organs into axolotls without any rejection issues. They have even transplanted eyes and parts of the brain.
The axolotl quickly accepts the donor tissue, heals itself, and continues living as if nothing happened. The organ functions normally soon after transplant without any outside influences.
As you can see, this trait is immensely interesting to scientists. If they could get the same results in humans, we could save many lives every year. So many people die while waiting on a match or their bodies reject a match, and later on, then they have to go on the waiting list again.
19. Axies Are Night Owls
Axolotls are considered nocturnal. While they don’t have eyelids, it is difficult to know when they are resting.
Taking into account that they like their environment to be a little darker than most anyway, and they frequently spend time just sitting still at the bottom of the enclosure, it’s hard to tell when they actually go to sleep.
There are times when axolotls try to find a hideaway for a while that’s darker and protected like a hide or a cave. It’s thought they are resting during this time.
When they are observed to be more active at night, scientists label axolotls as nocturnal animals.
20. Bad Water is Bad for the Gills
If you have read any of our guides for axolotls, you will know that these Mexican Walking Fish need pristine water conditions for their best health, but did you know, if the water gets too dirty, your axie could lose his gills?
Dirty water or high ammonia concentrations in particular can affect the external gills on axolotls.
Cleaning the water and removing the ammonia can help the gills to grow back, but the older the axolotl the slower they grow. In fact, the gills may not grow back to their original size if you have an adult axolotl who loses them.
Younger axies have a better chance of getting their full-sized external gills back. It’s not quite understood why this particular phenomenon happens, especially since axolotls seem to be able to regenerate nearly anything else back to the exact same size.
21. The Official Emoji
Okay, so you might have known most of the above facts if you have been reading up on axies before coming here, but I bet you didn’t know this one the axolotl is the official emoji for Mexico City.
Here’s an extra little axolotl fact I’ll throw in for you as well, 2022, 50 Peso bill in Mexico now features this cute, smiling amphibian on the back. Yes, the indigenous axolotl is immortalized on cold hard cash.
What are axolotl babies called?
Axolotl babies are called larvae. Mostly because they never advance past that stage, even when they are fully grown.
Can axolotls change color?
Yes, they can. While this doesn’t happen with all axolotls, sometimes juveniles can change their color a little as they get older.
Why do axolotls jump?
Assuming this question is asking about behavior when they snap up at food; this happens when axolotls suck in a mouthful of water to snap at their meal. The resulting rush of water sends the axolotl up and forward, giving the appearance of jumping. It’s just how they eat or attack their food.
That’s All Folks
There you have it. 21 interesting facts about the little amphibian that is everywhere and nowhere at the same time. We hope you have enjoyed this list and hope you have learned something in the process.
How did you do? How many did you already know before coming here? There’s no shame or hard feelings if you didn’t know any at all or if you knew everything on here.
What matters is you’re here sharing the same fascination that we do about the amazing axolotl.
More Axolotl stuff
- Axolotl care guide
- A guide on what axolotls eat
- Different types of axolotls
- How much does it cost to own an axolotl?
- A guide to the best tanks for axolotls
- Best filters for axolotl tanks
- Best plants to put in an axolotl tank
- Best chiller for axolotls
- A guide on how to breed axolotls