Mexican walking fish feared extinct

The salamander-like axolotl, also known as the “Mexican salamander” and colloquially as the “Mexican walking fish”, has apparently vanished from its only known natural habitat in Lake Xochimilco of Mexico City.

 

The salamander that never grew up

 

The axolotl is known for its wide head and face; stubby, underdeveloped legs with long, slim, digits; slimy tail; and external gill stalks that look like plumage. It is a type of amphibian that reaches adulthood without undergoing metamorphosis, retaining its juvenile characteristics—such as its gills—and thus staying in its larval form throughout its life.

 

The axolotl is also known for one other unique characteristic: its ability to regenerate lost limbs—including the minor parts of their brains. It is for this reason the animal is often the subject of much scientific study, which in turn means the axolotl can be found in many laboratories today.

 

It is an altogether different story in the wild.

 

Alarming decline

 

Millions of axolotl once made the giant lakes of Xochimilco and Chalco their home. In recent years, however, these lakes have been experiencing the negative impact of large-scale pollution and urban sprawl. 

 

In a three-month effort to find the creatures, researchers, including Luiz Zambrano (a biologist at Mexico’s National Autonomous University), were unable to catch any of the creatures in either lake. This February, another three-month attempt will be made in the hopes of finding any surviving free axolotl.

 

According to researcher Tovar Garza, the searches “on almost all the canals have to be repeated, because now we are in the cold season, with lower temperatures, and that is when we ought to have more success with the axolotls, because it is when they breed.”

 

The axolotl populations have actually been dwindling for years. In 1998, the Mexican Academy of Sciences conducted a survey which discovered that each square kilometer of the lake contained an average of 6,000 axolotls. In a similar 2008 survey, that number was drastically reduced to 1,000 per square kilometer.

 

Because of this sharp drop in their numbers, alarmed researchers have built “shelters” for the creatures in Xochimilco. These shelters protect the axolotl by providing them with clean water, as well as by preventing the entry of tilapia and carp that compete with the creatures for food. — TJD, GMA News