Thursday, March 15, 2012

Mexican Axolotl - Ambystoma Mexicanum

The Mexican axolotl (pronounced ACK-suh-LAH-tuhl) salamander has the rare trait of retaining its larval features throughout its adult life. This condition, called neoteny, means it keeps its tadpole-like dorsal fin, which runs almost the length of its body, and its feathery external gills, which protrude from the back of its wide head.

The axolotl, Ambystoma mexicanum, is a neotenic salamander, closely related to the Tiger Salamander. Larvae of this species fail to undergo metamorphosis, so the adults remain aquatic and gilled. It is also called ajolote (which is also a common name for different types of salamander). The species originates from numerous lakes, such as Lake Xochimilco underlying Mexico City. Axolotls are used extensively in scientific research due to their ability to regenerate limbs.
Axolotls should not be confused with waterdogs, the larval stage of the closely related Tiger Salamanders (Ambystoma tigrinum and Ambystoma mavortium), which are widespread in much of North America and also occasionally become neotenic, nor with mudpuppies (Necturus spp.), fully aquatic salamanders which are not closely related to the axolotl but bear a superficial resemblance.
As of 2010, wild axolotls are near extinction due to urbanization in Mexico City and polluted waters. Nonnative fish such as African tilapia and Asian carp have also recently been introduced to the waters. These new fish have been eating the axolotls' young, as well as its primary source of food. The axolotl is currently on the International Union for Conservation of Nature's annual Red List of threatened species.
Found exclusively in the lake complex of Xochimilco (pronounced SO-chee-MILL-koh) near Mexico City, axolotls differ from most other salamanders in that they live permanently in water. In extremely rare cases, an axolotl will progress to maturity and emerge from the water, but by and large, they are content to stay on the bottom of Xochimilco’s lakes and canals.
Close relatives of the tiger salamander, axolotls can be quite large, reaching up to a foot (30 centimeters) in length, although the average size is closer to half that. They are typically black or mottled brown, but albino and white varieties are somewhat common, particularly among captive specimens.
Axolotls are long-lived, surviving up to 15 years on a diet of mollusks, worms, insect larvae, crustaceans, and some fish. Accustomed to being a top predator in its habitat, this species has begun to suffer from the introduction of large fish into its lake habitat. Natural threats include predatory birds such as herons.
Populations are in decline as the demands of nearby Mexico City have led to the draining and contamination of much of the waters of the Xochimilco Lake complex. They are also popular in the aquarium trade, and roasted axolotl is considered a delicacy in Mexico, further shrinking their numbers. They are considered a critically endangered species.

Mexican Axolotl Facts:
Type: Amphibian
Diet: Carnivore
Average life span in the wild: 10 to 15 years
Size: Up to 12 in (30 cm)
Weight: 2.11 to 8 oz (60 to 227 g)
Protection status: Endangered
Did you know? : Because they have the ability to regenerate lost body parts, axolotls are probably one of the most scientifically studied salamanders in the world.

Mexican Axolotl Pictures

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