Saving an Aztec Salamander

Article excerpt

An effort to save the axolotl - a type of salamander - is also a bid to preserve an ancient culture.

The ancient waterways upon which the Aztec Empire was built are now a fraction of their former glory. Sucked dry by Spanish conquerors and subsequent urban planners, Mexico City's great lake is now little more than a network of canals in Xochimilco, a borough in the city's far south.

Hidden underneath the murky water, sharing space with discarded soda cans and empty potato-chip bags, an ageless "water monster" called the axolotl, a central figure in Aztec legend and a protein- rich part of the diet then, is also vanishing.

The creature is a type of salamander boasting a tuft of featherlike gills on its head and a "smile" that makes it seem more like a stuffed animal than a slimy amphibian.

The axolotl is found naturally only in this tangle of canals and channels, but urban growth, pollution, and the introduction of predatory fish have taken a heavy toll: The salamander population has shrunk 10-fold in the past five years alone. Today, scientists estimate that, at best, only some 1,200 are left.

Now a team of biologists in Mexico City is trying to save the axolotl (pronounced AK suh lot'l) from extinction. It's not just a matter of preserving an icon of the past: In laboratories around the world, axolotls are studied for their potential to aid war victims and others who have lost limbs, because they have the ability to regenerate lost or damaged body parts.

"It's not a panda in terms of cuteness," concedes Luis Zambrano, the lead biologist overseeing a bustling lab of students at the National Autonomous University of Mexico, who are monitoring the axolotl population in Lake Xochimilco. "But for historic, cultural, gastronomical, biological, and medical interests, they are, by far, more important than a panda."

At first glance, Xochimilco seems little more than a tourist trap, a Mexican version of Venice. Colorful gondolas called trajineras hold Mexican families lunching on tacos and mariachi ensembles looking for a buck.

Yet beyond the tourist route, narrow canals where marshland is accessible only by canoe and where trees form canopies across the waterways, Dr. Zambrano and his team are rebuilding channels to restore axolotl communities in the wild.

It seems a race against time. The International Union for Conservation of Nature has classified the axolotl as a threatened species. Zambrano's research suggests it could disappear in coming years if nothing is done.

On a recent day, a group of students measured the growth of salamanders that have been living in a refuge at the edge of a farmer's property, surrounded by irises that act as a natural filter and within nets to fight off the tilapia and carp that were introduced into the waters more than two decades ago and now feed on axolotl eggs whenever they can find them. …