Meet the water dog! More commonly known as the axolotl, the word axolotl loosely translates to “water dog” from the Aztec Nahuatl language .
This salamander species is pretty amazing. For one, the axolotl has a special life cycle where they skip the usual change into adults and instead keep their baby-like features throughout their whole life, a process called neoteny. This means they still have things like external gills, tails, and fins, and they don’t develop moveable eyelids.
Did you know that axolotls come in different colors? They are usually dark brown or gray with spots. They can even change their color to blend in and hide from predators, which is why muddy colors help them to survive.
The pink axolotls you see are actually bred by hobbyists who were seeking specific colors.
Axolotls are lentic animals, meaning they live in still waters. Even though axolotls lack fully developed teeth, they are effective predators. They use a suction technique when feeding on their prey of worms, mollusks, crustaceans, insect larvae, and small fish. When this happens, they also inhale gravel, which is thought to aid the digestion of food by grinding it up in place of teeth.
While these animals have captured the world’s attention for their cute looks and unique biology, there are still a lot of unanswered questions about the axolotl.
The axolotl’s amazing abilities of regeneration have scientists all over the world fascinated and stumped.
Axolotls can regrow lost or damaged body parts such as whole organs, limbs, and even central parts of the nervous system! Some researchers have even observed an axolotl regenerate a body part five times perfectly without scarring!
The axolotl, like humans, is a tetrapod, meaning it has four limbs. However, its genetic code is much bigger, with 32 billion base pairs—about 10 times more than humans.
The PAX3 gene is important for humans because it helps organs, bones, and tissues grow during early development. Even after this stage, PAX3 helps cells work properly.
In humans, PAX3 is also active in cells that help produce pigments for hair, eyes, and skin. This gene is found in other animals too, like mammals, fish, and amphibians!
Back to axolotls, after a lot of genetic research, it has been discovered that axolotls lack the PAX3 gene, however in its place, they contain a similar working gene called PAX7.
Studies have demonstrated that this unique gene carries out the same functions as PAX3 and is crucial in the development and growth of body parts.
It is also thought that the secret to their regeneration is linked to their consistent juvenile state, as the PAX genes are essential to embryonic growth.
Additionally, It has been discovered that the noncoding parts of axolotl DNA are 12 to 17 times bigger than those in humans! This shows that their ability to regrow limbs is affected by unique genes and DNA structures specific to their species.
While there is still so much to uncover, these exciting new developments in genetic research mean that we have come one step closer to understanding naturally occurring regeneration and how we can apply it to human medicine!
Unfortunately, these animals are critically endangered in the wild. It is thought that there are less than 100 axolotls in their natural habitat.
With few natural predators, the axolotl’s biggest threats are urbanization and pollution. Native to the lakes and wetlands of Southern Mexico City, specifically Lake Xochimilco and Lake Chalco.
85 years ago, multiple drainage projects underwent these areas to reduce flooding and consequently critically disrupted the axolotl’s habitat.
Though their conservation status is alarming in the wild, these animals are abundant in the hobbyist community and in scientific research laboratories across the world.
As a conservation effort, “shelters” of rocks and reedy plants are being built to aid the flow of clean water in Southern Mexico.
We can do our best to monitor our own overall environmental impacts, such as properly recycling, seeking out sustainable and local food sources, or reducing our plastic waste when we can. If you don’t already, try using a reusable water bottle!
These amazing creatures deserve all the attention they get, be sure to swim by Ripley's Aquarium of Canada and get up close with our amazing axolotls.
Julia Nalywaiko, Ripley’s Aquarium of Canada Educator
My name is Julia, and I am an Educator at Ripley’s Aquarium of Canada. I have always had a passion f…
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