Simply put, the axolotl (ax-uh-lot-ul) is a salamander that spends its entire life in water.  Facilitation of this lifestyle is achieved by the retention of ancestral juvenile characteristics like gills and a finned tail.  It is one of 30 species in the family Ambystomatidae, the largest family of salamanders in the world.  The tiger salamander, Ambystoma tigrinum, is virtually indistinguishable from from the axolotl during the larval stage and is considered the species of closest relation (Brandon 1989). 
    Axolotls can grow to as much as 7 inches in length, and generally feed on worms, insect larva, crustaceans, and wounded fish (Sedgewick 2000).  While most live between 10 and 15 years, the oldest on record stands at 25 years of age (Mayfield 2000 ). 

     Scientists were not the first to uncover the unique nature and benefits of the axolotl.  Being indigenous to the preexisting lakes Xochimilco and Chalco along the southern rim of the Mexican Basin, naturally it was the Aztecs who first found the axolotl and adopted it into their way of life (Brandon 1989).  They considered it a plentiful and delectable food source, due to the scarcity of large sized fish on the Mexican plateau (Smith 1989). 

  
(Image courtesy of the IU Axolotl Colony)..


The lakes of axolotl origin. A depiction of the Basin of Mexico before the sprawl of Mexico City.
 

(Image courtesy of Hobart Smith)

An illustration of the Aztec god Xolotl in his dog like form. Rendered by Nicholson from the Borgia Cordex (1959) . 
 
    Serving as a staple food in the Aztec diet, naturally the axolotl earned a special place within the society's culture and religion.  The name axolotl comes from nahuatl, the language of the Aztecs.  Its derivation is considered in part, a reference to their god Xolotl.  As myth follows, this deity assumed many forms to avoid banishment from the earth, however he was eventually captured and killed as an axolotl (Smith 1989).

     Cortés's early 16th century conquest of the Aztecs seemingly introduced the word Xolotl into the Spanish language.  Although it is somewhat derived, the word ajolote (Ah-ho-la-teh) means water dog, water sprite, water monstrosity, etc. (Smith 1989).
    It was not until French occupation of Mexico during the middle half of the 19th century, that the axolotl made its way into the world of science (Armstrong and Malacinski 1989).  In 1863 General Forey's French expedition sent the first collection of axolotls, consisting of five males and one female, to the National History Museum in Paris.  With the subsequent addition of an albino in late 1866, this group of axolotls was eventually donated to renowned physiologist Auguste Duméril for scientific investigation.  Interestingly enough, a large percentage of the axolotls in captivity today came from this original stock (Smith 1989).

     Over the course of the last 100 years or more, the axolotl has remained a focal species within the field of developmental biology.  Researchers continue to study it for the purposes of embryonic induction, pattern formation, organogenesis, regeneration and more (Armstrong and Malacinski 1989). 

     In addition to the axolotl's application in the aforementioned areas of developmental biology, the animal has also served as a wonderful tool for exploring the role of metamorphosis in amphibians.  As a paedomorph, the axolotl offers excellent opportunities for understanding the role of larval characteristics in controlling or limiting the evolution of adult features (Hanken 1999).


 
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                                      This page was last updated on October 19, 2000