There are other salamanders in the animal kingdom that dwell in water as well as on land, but none so peculiar as the axolotl. Characterized by two pairs of frilly external gills on either side of its head and elongated fingers on front and back limbs, the axolotl is unique among aquatic salamanders because it is neotonic, meaning that it never metamorphasizes into an adult phase, remaining physically in the larval stage for its entire life. Although the axolotl possesses lungs that can breathe air, it lives an entirely aquatic life, breathing through its gills. Curiously, when metamorphosis was manually induced, the axolotl’s life span was reduced by more than 50 percent, seemingly indicating that evolution produced the axolotl for a reason!
This bizarre aquatic salamander once densely populated the freshwater lakes of central Mexico, even serving as a food staple for the Aztecs, who called the creature “water monster.” However, ecological changes in habitat due to development and urban growth have concentrated their remaining populations primarily in Lake Xochimilco, a water body that has been reduced to a series of canals. Additionally, non-native species like Asian carp and African tilapia are playing a major role in its extinction, as they like to feed on the young of the axolotl. Not surprisingly, the axolotl is listed as critically endangered, and much effort has been focused on breeding in captivity in an attempt to increase their numbers. Let’s hope we can find a solution for the axolotl’s problems before this fascinating creature slips quietly out of existence.
What do you think: is the axolotl a beauty or a beast?
Top image via roselle.kingsbury