Since then, the salamander with a Mona Lisa smile has become an icon of Mexican culture and inspired countless researchers because of its capabilities to regenerate bits of its body. Though approximately 1 million of them can be found in labs and pet stores across the world, the axolotl (pronounced ack-suh-lah-tuhl) is on the brink of extinction in the canals of Lake Xochimilco in southern Mexico City, its only natural habitat.

In hopes of preventing the annihilation of a species with mystifying traits, ecologists at Mexico’s National Autonomous University are giving the public the chance to virtually adopt an axolotl. For $30, $180 or $360, donors can choose the sex, age and name of the little buddy they get to call theirs for a month, six months or a year, respectively. The axolotls stay in Mexico, but donors receive an adoption kit with an infographic, the axolotl’s identification card, a certificate of adoption and a personalized thank-you letter.

The campaign also includes options to buy an axolotl a meal for $10 or to fix up one of their homes for $50. And for those wanting to splurge a bit more, participants can adopt the axolotl’s refuge of chinampas — the artificial islands that dot Lake Xochimilco — for one, six or 12 months starting at $450.

The funds will go toward building refuges for the axolotl and restoring its habitat, which has been devastated by the effects of Mexico City’s urbanization over the last decades, said Luis Zambrano, an ecologist at Mexico’s National Autonomous University.

“A species can’t be a species without its habitat,” Zambrano said.

Present-day Mexico City bears little resemblance to the ancient water world of Tenochtitlan. The Aztecs built their capital of palaces and pyramids atop an island in a giant lake, using a complex system of canals and dikes to prevent it from flooding. Farming was done in chinampas, rectangular plots of lands in the shallow lakes surrounding Tenochtitlan that were separated by canals, which helped filter the water. The axolotl, Zambrano said, thrived in this environment, and it quickly became a staple of the Aztec diet.

But then the Spaniards arrived and, in the 1600s, decided to drain the lake, leaving Mexico City resting atop its basin. Lake Xochimilco is the last remnant of the city’s watery past — and the only remaining place where axolotls can be found in the wild.

Over the next several centuries, the city’s expansion and growing population turned Lake Xochimilco into a shrinking, polluted matrix of canals throttled with hungry fish imported from other continents — both of which depleted axolotl populations. In the 1970s, Zambrano said, the Mexican government introduced African tilapia and Asian carp into the lake in an effort to create fisheries, but the fish began eating the axolotl eggs and young. And the water’s diminishing quality has sickened the axolotls, which breathe through their skin.

When scientists in 1998 conducted their first census of the axolotl population, there were about 6,000 for every square kilometer in Lake Xochimilco. The last count, in 2014, showed there were only about 36 axolotls per square kilometer, Zambrano said.

“We went from 6,000 to 36 in less than 20 years,” he said. “We need funds to conduct another census, but the outlook is grim. It’s more than likely that they’re nearly extinct.”

Losing the axolotl in the wild “would be incredibly bad for both Mexican culture and the science world,” Zambrano said.

In Mexico, images of the axolotl are ubiquitous. They grace murals and were chosen as Mexico City’s official emoji. They have figured in works by artist Diego Rivera and texts from poets and authors such as Julio Cortázar, Aldous Huxley, Primo Levi and Octavio Paz. Their likeness is even splashed across Mexico’s 50-peso bill.

Apart from that, axolotls are a scientific wonder. For starters, the axolotl is the Peter Pan of the animal world. Even though amphibians typically go from egg to tadpole to land-roaming adult, the axolotl simply refuses to grow up, sticking to a life in the water, like a pseudo-tadpole.

“In biological terms, it’s a really interesting creature because it rebuffs metamorphosis, and that’s very attention-grabbing when it comes to understanding evolution,” Zambrano said.

Axolotls have the remarkable capability of restoring lost body parts, from limbs to eyes to brains. That’s made them a prime research subject in the areas of regeneration, aging and cancer. Axolotls have also helped scientists understand how organs develop in vertebrates, uncover the causes of the birth defect spina bifida and discover thyroid hormones.

“That’s why there are so many of them in labs all over the world,” Zambrano said.

The salamanders have also become beloved exotic pets — to the point that “there’s claw machines in Japan that let you pick up an axolotl to take home,” he added.

But even as the species is racing toward extinction in its own home, Zambrano, who has led the efforts to conserve Lake Xochimilco’s axolotls for over two decades, has not lost hope. He and his team are betting that the Pokémon-looking creatures could be saved by creating refuges for them in their native habitat. The plan involves chinampas.

The chinampas, he said, “are essential” to the efforts since they naturally help clean the lake’s polluted water — not unlike, say, a Brita filter — and improve its quality. These plots of land are also a source of food and shelter, and can help the axolotls hide from the pesky herons that want to eat them.

Last year, when the adoption campaign first launched, it raised almost $30,000, covering about 40 refuges. But to expand and continue to maintain them, the ecologists need about 10 times more funding, Zambrano said. So far, they’ve more than doubled the amount of donors compared to last year.

“We’re in a very critical moment where we’ve been saying for the last decades that time is running out for the axolotl,” Zambrano said. “But we can’t just sit down and wait for the government to act.”

“Like we say here in Mexico,” he added, “todos tenemos que sacar al buey de la barranca” — we need to take the bull by the horns.