The Mexican “Water Monster” Resurfaces: Freshwater Species of the Week

Photograph by fronx, Flickr

The last few weeks have been pretty eventful for the axolotl (Ambystoma mexicanum), a critically endangered Mexican salamander.

At the end of January the charismatic creature was feared to be extinct in the wild when a three-month survey in its natural habitat, Lake Xochimilco in Mexico City, turned up no axolotls, according to biologist Luis Zambrano of Mexico’s National Autonomous University (UNAM).

Then, in a pleasantly surprising turn of events, the axolotl was spotted in the lake earlier this week during a second round of salamander searching according to biologist Armando Tovar Garza, also of UNAM.

There may have been a sigh of relief, but biologists still aren’t thrilled with the outlook for the species, as its population has drastically declined in recent years due to pollution and habitat loss.

Iconic Organism

Axolotls, which are bred in captivity as exotic pets, have gills that extend from the sides of their necks and unlike most amphibians, live underwater full-time.

freshwater species of the weekThe animals also have the unique ability to regrow tissue when wounded—even up to growing an entirely new limb, tail, and parts of organs, including their brain and heart. (See also: “5 Animals That Regrow Body Parts.”)

“It’s a very iconic organism, and it’s been important in research for a long time” because of its odd regenerative abilities, said David B. Wake, a biologist and curator of the Museum of Vertebrate Zoology at the University of California, Berkeley.

“At one time, Mexico City was really an aquatic city, and over time [Lake Xochimilco] has been drained and reduced in size and gotten polluted,” he added.

Skin Of Their Teeth

Now axolotls are struggling to survive in much smaller environments.

“The lakes of Xochimilco are not going to get bigger. Unless those areas are diligently kept in order, axolotls are definitely in danger,” he said.

The recent news of the Mexican water monster’s brush with extinction is just another important reminder of how water issues can lead to the loss of much-loved species in their true homes, he added. (Learn more about freshwater threats.)

“So many species are just hanging on,” said Wake, “literally by the skins of their teeth.”



Meet the Author
Sonia Harmon is the blog coordinator at National Geographic. She has also written for Ladies' Home Journal magazine and Washingtonian magazine.