This is no world for an axolotl

Basilio Rodríguez casts his net with a masterful swing, launching it into the air before it falls, sinking into the water. He then smacks the two sides of the canal with a wooden pole. Fish emerge from their hiding places among the reeds and head straight into the net. When he pulls up the catch, his net reveals a tilapia and a couple of juvenile carp — not what he is looking for, which is axolotls, the strange Mexican amphibians teetering on the brink of extinction.

The scientists accompanying him on the trajinera, or flat-bottomed boat, tally another zero in their field notebooks. Dawn is a magical time on the canals, suffuse with a fog reminiscent of Dublin that hangs over the water. An orange half-sun appears over the horizon. It is chilly here until light breaks over Mexico City’s southern sky. Again and again, the nets come up empty.

The axolotl, whose name comes from the Nahuatl language indigenous to the Mexico City area, is an amphibian so singular that it could well appear on the country’s flag instead of its eagle and serpent. It has an impressive resume, being the most studied animal in the world, subject of more investigations than even the Drosophila melanogaster or common fruit fly that resides in thousands of laboratories around the world.

Of all the curiosities among the planet’s fauna, the axolotl’s regenerative abilities are enviable: if one of its legs is cut off, a new limb will grow in a few hours, identical and pristine. The same process occurs with any other part of its awe-inspiring form. In his travels as a naturalist throughout Mexico, Germany’s Alexander von Humboldt first encountered the axolotl at the beginning of the 19th century, but it was French zoologist Auguste Duméril who came up with its most perfect description, years later: it seemed to him an animal who rebelled against God. Every morning, Duméril carefully cut off the external gills that flank the axolotl’s face. By the next day, the creature had grown a new set. The zoologist knew that for other amphibians, these gills were characteristic of the larval stage. But the axolotl refuses to grow up.

The Frenchman’s findings were accurate, but the research of his era did not manage to clarify what scientists at the National Autonomous University of Mexico (UNAM) now know. The regenerative magic of the axolotl is due to the fact that it lives forever in a larval state, like a fetus, during which animals form their body parts, thanks to stem cells. The creatures can live for four to six years in captivity, their lifespan in the wild is still undetermined. In addition, it is now known that in situations of extreme stress, the axolotl grows into a salamander. There is one specimen that has undergone this shift in Luis Zambrano’s laboratory at UNAM’s Biological Institute. It has lost its gills and transparency; its tail has thinned. It’s not expected to live longer than a year.

At the Biological Institute, as they are in hundreds of other laboratories around the world, the axolotl’s rarities are studied to see if its astounding qualities can be of use in the world of medicine, in combating the signs of aging or in edging humans closer towards eternal life, or 150 years of existence, at least.

That is why Rodríguez, the trajinero hired by UNAM, casts his nets again and again in Xochimilco, the Mexican capital’s great wetland that was once the source of food and water for the Mesoamerican people who lived in the area well before the Spanish arrived in the 16th century. From that point on, and until the early years of Rodríguez’s lifetime, the axolotl (which can measure between 15 and 35 centimeters in length) was part of the local diet. Dozens of types were captured by net to wind up in the cooking pot.

“The axolotl is smooth, soft, juicy, very rich with no bones, just cartilage that can be prepared just like that, on the griddle, with a little salt and a tortilla,” says Rodríguez, licking his fingers to emphasize the taste.

But it’s not the local gastronomy that has exhausted the amphibian’s population in nature. No, the usual trio of culprits are to blame: habitat destruction (lands once occupied by vegetable gardens in Xochimilco are now the site of urban development and soccer fields), worsening water quality (which has steadily declined due to the presence of treatment plants and plastic waste in the canals) and finally, climate change, which has led to higher temperatures.

Axolotls experience stress when it gets hotter than 66 degrees Fahrenheit. To make matters worse, invasive species have been introduced to the area such as the tilapia, which feeds not on the axolotl but its eggs, and is capable of gobbling down the 600 ovules that females have been known to lay. Of course, the axolotl itself is no slouch in the carnivore department, according to biologist Vania Mendoza, who shares aboard the trajinera that, “On the food chain, it is comparable to the shark, a nocturnal hunter. It eats all crustaceans smaller than itself and its only predators are water snakes and some birds, such as herons. But tilapia eat a broader variety, hence their survival advantage.”

Mendoza is the coordinator of the census that every few years is carried out by UNAM in the natural habitat of the Ambystoma mexicanum by casting nets around Xochimilco. In 1998, its measurements found 6,000 axolotls per square kilometer, but by the start of this century, their future seemed bleak, as the following censuses confirmed, documenting less than a dozen in the same area. This year, they haven’t found any. But no one is throwing in the towel.

“We don’t classify an animal as extinct until 10 years have passed without any sightings,” says Zambrano. Then there are the DNA tests that Mendoza and the census team’s Viviam Crespo and Paola Cervantes will carry out. “Those will tell us if there are or have been axolotls within a 200-foot radius, it’s not very precise,” says the coordinator, adding that such tests could nonetheless serve to keep hope alive for the amphibian.

In Mexico there are 17 species of Ambystoma of varying colors, from yellow to green to the black axolotls native to Xochimilco, one of the most curious — and undoubtedly the most famous. Ambystoma live in lakes and rivers all the way up to the United States and Canada, but “the majority of the 17 species are at risk of extinction,” says Zambrano. Just three have been classified as safe from this danger, and there is no precise data on two of them. “The Ambystoma is a forced neotenic. That is to say, if it transforms [into a salamander], it dies quickly,” explains the senior researcher. The Xochimilco axolotl does not transform regardless of the stress it experiences, which makes it a valuable subject of study for scientists.

Is all this to say that the world is condemned to losing the axolotl? Not necessarily. In fact, the animal is becoming more and more common as a pet. It reproduces easily in captivity, resulting in easy money for those that sell them. For $5 to $25, you can buy one to adorn your living room aquarium, which has meant that the hundreds of labs that study the creatures have a steady supply. Even as it disappears from its natural habitat, the little guy’s fame has spread across continents.

In Japan, the axolotl figures as the logo of a soup brand. In South Korea, it is all the rage, its silly smile beaming out everywhere from T-shirts to baseball hats, keychains to ceramics, magnets, towels and beach balls. On the streets of Mexico, axolotl souvenirs of all types are sold by vendors. Zambrano surmises that one particularly colorful type, the half-yellow-and-half-pink albino, has multiplied due to the advantages it offers in lab research: when scientists inject it with fluorescent material in order to observe its body’s reactions, no microscope is necessary, as they can be seen with the naked eye. The albino axolotl has also become a popular denizen of home aquariums. They are quite fetching, truth be told.

Of course, prevalence as pets is not akin to species survival. “People confuse conservation with aquariums,” laments Zambrano, who has spent years advocating for the restoration of Xochimilco so that it can once again be home to the axolotl, free of tilapia and chemicals. Studies have found that it will cost $30 million to carry out the renovations that this would require. But more importantly, there is a lack of political will and a surfeit of planning obstacles, such as the construction of bridges that are breaking up the wetlands.

The scientists have not lost faith. Maybe things will change during the current presidential administration, they tell themselves every morning. Meanwhile, the project to save the axolotl continues as it has for three years, with all sorts of bureaucratic impediments, it should be added. For $30, one can adopt an Ambystoma for a month, name it and visit it at Zambrano’s laboratory, where Horacio Mena González oversees the blue bathtubs housing 140 specimens. A little more money extends the adoption to six months or a year. Those looking for a lower investment can invite an axolotl to dinner for just $10. Last year, the university raised $200,000 in this manner.

UNAM’s fundraising efforts go to support the chinampas, the vegetable gardens that the Indigenous people of the Valley of Mexico have been building since the pre-Hispanic era in the middle of the waterways by driving stakes into the water, forming walls that are then filled with mud and seeded. Today, the Xochimilco landscape continues to be astounding, particularly at dawn and dusk. Area farmers’ canoes transport lettuce, cabbage, cilantro, red turnips and beautiful loads of squash blossoms that resemble rays of sunshine. It’s an idyllic spectacle that has attracted traffic jams of tourists.

The nearly 108 square miles of protected wetlands surrounded by towns and markets make up an indispensable area of the great Mexican capital. These gardens supply the city’s most renowned restaurants and some chinamperos put in great effort to maintain sustainable traditional cultivation techniques.

One of them is Carlos Sumano, who bought a chinampa (hundreds have been abandoned) and planted it with vegetables and flowers. No chemicals are used on the land, which is no larger than a soccer field. Sumano is an agricultural development planning expert and works in Zambrano’s laboratory. The UNAM team is spreading awareness among chinamperos of the viability of techniques like those that Sumano has employed, such as surrounding gardens with a small ditch that prevents the access of tilapias, but that allows water to flow from the central canal, apt for the reproduction of axolotls and opening the door to their Xochimilco renaissance. But though subsidies can help, it is still difficult for agricultors to give up modern-day production systems that can often be more profitable.

Axolotls like fresh water and silence, which is a lot to ask for in Mexico. Trajineras playing loud music pass constantly by chinampas whose owners live off tourism, primarily exhibiting, yes, axolotls in aquariums. Some of the gardens have been converted to event spaces for weddings, baptisms and quinceñearas. When the party’s over, bottles and other trash wind up in the waterways.

The spectacle of the colorful boats can be overwhelming: hundreds of them ferry drunken tourists and groups of mariachis, others sell anything one might desire for a leisurely day on the water. Noise, parties and a fair amount of trouble are nearly guaranteed on any given weekend. This is no world for an axolotl. Every once in awhile, some politician will conduct a farse of an amphibian re-introduction ceremony that complies with none of the standards for handling the creatures. Even before the media coverage has faded out, the axolotls in question will be dead, victims of a habitat no longer suitable for their species.

Dawn breaks over Rodríguez’s watercraft. The team of scientists takes off their outer layers of clothing as the rays of the sun hit. Time will tell if there’s any luck with the nets during one more day of carrying out the 2014-2025 census — or if the project itself will prove to be pyrrhic, null. Electric cables crisscross the sky. Birds perch atop them. Hundreds of pelicans fly by, once again making Xochimilco a stopover on their migratory route. Plastic bottles of Coca Cola and other soft drinks nestle into the reeds where axolotls once lived.

According to the mythology that sprang up in these lands, Xólotl, the twin brother of Quetzalcóatl and the god of fire, lightning and spirits, refused to be sacrificed alongside the rest of the gods in exchange for the creation of the universe. In his flight, Xólotl turned into a turkey, then a dog, into a maguey plant and then corn, until desperate, he threw himself into the lake in the shape of an axolotl. This small sacred animal, whose name means “water monster,” is once again in mortal danger, though today, no one seems capable of saving it. Rodríguez casts his nets into the water once more and observes bubbles emerge from the mud, just as the ancient fishermen once did. If they were small and close together, they might have indicated the breath of the axolotl, that Peter Pan of amphibians. But they are large, created only by his oar striking the riverbed’s silt.

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