Where do Axolotls live and why do they look so strange?

The axolotl (Ambystoma mexicanum) fell into mythology centuries ago; the Aztecs believed that the first axolotl appeared in the lake system surrounding modern-day Mexico City when the powerful underworld god Xolotl transformed himself into a small, feathered amphibian to escape capture.

Among the first modern zoo animals, 34 axolotls were brought from Mexico (along with three deer and three wild dogs) to the “Jardin zoologique d’acclimatation” in Paris in 1864. where do axolotls live? today, and why do they look so strange to us?

Where do Axolotls live?

Axolotls are a large, endangered species of salamander that live in freshwater, specifically Lake Xochimilco in the southern part of Mexico City. Even though they are sometimes called “Mexican walking fish,” they are amphibians and not fish at all.

What do Axolotls look like?

In the wild they are usually dark brown or black with speckles, but leucitic or albino varieties are common and are often seen as pets.

With their round heads and permanently smiling faces, wild axolotls are adorable (it’s one of the reasons they do well in the pet trade). One reason for the cuteness overload is neoteny, the retention of youthful characteristics throughout adult life.

For example, although adult axolotls also have functional lungs like other amphibians and can breathe through their skin, they have large, fluffy external gills – something other amphibians do not retain after infancy.

They have small, delicate webbed feet and a long, tadpole-like tail with a translucent fin, because they do not rely on their webbed feet and legs for land travel, but they must be able to move through the water like a large tadpole.

Stable habitat, stable characteristics

Scientists think they remain baby-like throughout their lives because, unlike other salamander species, the wild axolotl population has evolved in very stable habitats. Other species of salamanders, such as the tiger salamander, live in wetlands that dry up during certain parts of the year, so they must lose their feathery gills and breathe through functional lungs and through their skin.

Wild axolotls evolved in a habitat with year-round water and very few aquatic predators, so they did not have to expend energy altering their bodies to suit their changing circumstances.

The life cycle of the Axolotl

The lifespan of an axolotl is about 15 years in captivity, but a wild axolotl probably lives only five or six years. They reach sexual maturity after a year, and although they are for the most part solitary creatures, in February the breeding season begins and wild axolotl males begin to find females using pheromones.

When they come together, the male does a courtship dance where he shakes his tail in her direction. After the female agrees, she pokes him with her nose and he deposits a sperm packet at the bottom of the lake, which she picks up and uses to fertilize her eggs.

The female wild axolotl lays hundreds of eggs in the weeds or around some rocks and then leaves them to fend for themselves; baby axolotls do not receive any parental care.

Baby axolotls, hungry after hatching from their eggs, have even been observed gnawing on the legs and tails of their siblings to sustain themselves. As you’ll see, this is completely fine as the legs will simply grow back later.

Pink predators

In their home ecosystem, axolotls are – or at least were – top predators around the lakes, wetlands and canals of central Mexico. They are unusual among amphibians in that they remain submerged their entire lives and breathe through feathered gills, while most other salamander species are terrestrial and breathe with the lungs during the adult stage of life.

Although they appear unassuming, they are actually ruthless carnivores, feasting on worms, mollusks, insects, insect larvae and even small fish in the wild.

Regenerative abilities

Part of the Aztec mythology of the axolotl revolves around the fact that, like a powerful god, they are difficult to kill. An axolotl can regenerate virtually any body part it loses, no problem. While some lizards can regrow a tail, bisected flatworms can regrow their other half and starfish can regrow a limb, an axolotl can regrow virtually any part of its body in a few weeks.

“Of the animals closest to us – the vertebrates – salamanders are the only ones that can regenerate in this way and heal without scarring,” says David Gardiner, professor at the University of California’s School of Biological Sciences . Irvine, when we spoke to him in 2019: “Other salamanders can regenerate, but axolotls do it best.”

When Europeans caught wind of axolotl regeneration, axolotls went from a zoo exhibit to one of the most important and longest self-sustaining laboratory animals in history.

Georges Cuvier, popularly considered the father of paleontology, studied axolotls in an attempt to find out whether Carl Linnaeus was right in categorizing the classes Amphibian And Reptilia individual. Cuvier concluded that because axolotls breathe through gills their entire lives, they must be a type of lizard that existed as a perpetual larva—in the words of paleontologist Stephen Jay Gould, a “sexually mature tadpole.” (Cuvier was sometimes right, but not in this case.)

Because axolotls did incredibly well in laboratory and aquarium environments, 19th century zoologist Auguste Duméril took it upon himself to supply every laboratory in Europe with a supply of axolotls, resulting in some truly gruesome studies in which scientists used laboratory axolotls in chopped pieces to test them. the limits of their regenerative powers.

Scientific studies on Axolotls

Scientists are interested in axolotls because they hope to figure out how to one day apply the miraculous new capabilities of limb regeneration to the human body. Axolotls can regenerate limbs, heart tissue, eyes, and even the spinal cord and parts of the brain, creating new neurons throughout their lives, which human brains also do, although not as easily.

“Today, axolotls are hugely important model systems for our studies of regeneration,” says Gardiner. ‘We have known for decades – centuries even – that we can remove parts of a developing embryonic structure and that the cells that remain will fill in, repair and regenerate that structure. But in most animals – mammals, for example – the system shuts down at the end of embryonic development. Axolotls and other salamanders appear to be able to return to that embryonic state, regaining access to the developmental program that is already there. People have the program, but we simply don’t have access to it anymore when we’re no longer an embryo. You could say that, like axolotls, we have developed the ability to regenerate very well, but we have also developed a mechanism that inhibits that.’

It is possible to force an axolotl to turn into an adult salamander without gills by injecting it with iodine or thyroxine, or by feeding it food rich in iodine. However, scientists have discovered that after undergoing metamorphosis, they do not easily regenerate cells.

The dangers facing wild Axolotl populations

Wild axolotls may be godlike in their evolved ability to re-access embryonic instructions to regenerate organs and limbs – captive axolotls might even be able to live in a grim 19th century aquarium or laboratory, broken up into small pieces – but what they haven’t been able to tolerate is their home ecosystem being overrun with introduced predators, environmental toxins and habitat loss.

Their home lakes around ultra-urbanized Mexico City have become not only polluted by outdated wastewater systems, but also overrun by invasive fish species such as tilapia and bass, both of which axolotls happily eat. All this has put the axolotls in danger.

Conservation efforts

The Mexican government and many axolotl conservation groups throughout Mexico are doing their best to save the endangered salamander species by restoring the lakes and natural habitats in which they live.

One strategy is to create stationary floating island habitats for them chinampas – rafts made of aquatic plants, mud and wood that were used as floating gardens in ancient Mesoamerican culture.

Hundreds of years ago, when the Aztec capital Tenochtitlan stood on the site of Mexico City, the Aztecs built and farmed an extensive network of chinampas for miles around the capital. This agricultural system created channels that were shallow and sheltered, and where the axolotl population thrived.

When the European conquerors arrived in 1519, they destroyed the Aztec civilization, removed the chinampas and dried up the canals and lakes.

Now the natural habitat of the wild axolotl population is limited to Lake Xochimilco. People are working to remove the invasive species that threaten the axolotls’ habitat, eat the axolotls, and begin using chinampas-based agriculture in Lake Xochimilco, because the aquatic vegetation of chinampas not only provides habitat for the axolotls, but also filters toxins from the lake water.

These chinampas’ ecotourism has helped fund axolotl conservation efforts.

Axolotl populations in captivity

Although the wild axolotl population is not doing well, captive populations are doing very well. they are the most widely distributed amphibians in the world.

Because scientists are desperate to figure out how to help you regenerate a new set of toes, millions of them live in laboratories around the world – millions more, in fact, than in the wild. And while axolotl research is important in science, captive populations of axolotls are also popular in Japan, a country where you can also get axolotls as a fried snack in some restaurants.

Important notes for pet owners

It is not legal everywhere for pet owners to keep an axolotl as a pet, so it is important to check local exotic pet laws before purchasing one. Because they live entirely in water, it is important to fill the tank completely with water; a tank of 57 to 151 liters is best.

Like a small fish, never pick up or handle an axolotl, and you should never house it with another pet – a fish or another axolotl – because it doesn’t get along with anyone.

However, if you follow these few basic rules, you will find them relatively hardy and easy to care for. Naturally, you must pay close attention to how you handle critically endangered species.

Original article: Where do Axolotls live and why do they look so strange?

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