The axolotl, Ambystoma mexicanum, is a neotenic salamander, closely related to the Tiger Salamander. 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.
Outside Mexico, the axolotl is more popular as a pet than a snack. It can today be found in pet shops world-wide, sometimes being offered under other names such as Wooper Rooper or Mexican Water Monster.
Now "our best estimates using unpublished data, but with two different techniques, sampling and genetic, suggests that the total amount of axolotls in the wild is between 700 and 1,200 animals," says Dr Zambrano.
In the wild, A. mexicanum lives ten to twelve years. Its major predators are predatory birds such as herons.
While young, A. mexicanum feeds on algae, but as it grows older, it takes to eating aquatic insects.
Males and females mate underwater and the females lay eggs on nearby structures such as plants.
The name "Ambystoma" means cup-mouth, and axolotls do have large, wide mouths. When an axolotl wants to eat something, it opens its mouth suddenly and water rushes in, along with the food or anything else around (such as parts of other axolotls, or pieces of gravel). This vacuum action often results in a sudden lurch of the axolotl up into the water and then the animal settles down again.
AB Urodele amphibians, such as the axolotl (Ambystoma mexicanum), have the unique faculty among vertebrates to regenerate lost appendages (limbs and tail) and other body parts (apex of the heart, forebrain and jaw) after amputation. Interestingly, axolotls never seem to form scar tissue at the site of amputation once regeneration is completed. Histological analysis of wound healing confirmed the absence of tissue fibrosis throughout the process and shows that skin integrity is re-established by 90 days after wounding. Results also reveal the absence of neutrophils in the wound area, suggestive of a lack of or low inflammatory response.
The axolotl grows much larger than a normal larval or neotenic salamander species, and it reaches sexual maturity in this larval stage. Axolotls have distinctive fern-like gill structures that are uncovered or external – usually three stalks on each side of the head. They have tiny teeth which are used to grip food rather than to tear and chew it. In body colour, axolotls range from albino or white (the leucistic variety) to black, through greys, tans and browns. However, leucistic axolotls are rarely found in the wild.
Unlike related tiger salamanders that undergo metamorphosis, axolotls retain larval morphological traits into adulthood and thus present an adult body plan that differs dramatically from the ancestral (metamorphic) form.
The Mexican axolotl, Ambystoma mexicanum, is a strictly aquatic species that persists currently in two highly threatened and isolated populations. The current habitat remaining for these species are remnants of a historically extensive lacustrine system that occupied the entire Valley of Mexico, but has been destroyed by the growth of Mexico City. Unexpectedly, a third viable population of axolotls has been found in Chapultepec Park, a public recreational area in the heart of Mexico City.
The axolotl is an Ambystomatid or mole salamander found only in the Laguna Alchichica in eastern Puebla, Mexico at an elevation of 2,290m above sea level. Mole salamanders are medium to large, stocky salamanders, usually measuring between 90 to 350mm from the tip of the nose to the end of the tail, which salamanders retain throughout their life. Males are often larger than females, owing to their longer tails. Ambystomatids are often boldly patterned as adults, with well-developed costal grooves (successive vertical grooves along the sides of the body), especially the metamorphosing varieties. They have a rather flattened body with a wide, flattened head, a large mouth and smooth skin with many glands.
During the Aztec empire, the axolotl was an important food item as well as an integral part of numerous myths and legends. According to legend, the Aztec god Xolotl – who was in charge of death, lighting and monstrosities – suspected the other gods of plotting to banish or even kill him, and turned himself into a salamander in order to fool them. He moved to Lake Xochimilco where he could stay hidden from the other gods and Xolotl became a-xolotl, blessing the Aztecs with an important source of food.