Axolotl

The Axolotl (or ajolote) (Ambystoma mexicanum) is the best-known of the Mexican neotenic mole salamanders belonging to the Tiger Salamander complex. Larvae of this species fail to undergo metamorphosis, so the adults remain aquatic and gilled. The species originates from the lake underlying Mexico City. Axolotls are used extensively in scientific research due to their ability to regenerate most body parts, ease of breeding, and large embryos. They are commonly kept as pets in the United States, Great Britain (under the spelling Axlotl), Australia, Japan (where they are sold under the name ), and other countries.
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Noun
1. larval salamander of mountain lakes of Mexico that usually lives without metamorphosing
(synonym) mud puppy, Ambystoma mexicanum
(hypernym) ambystomid, ambystomid salamander

(n.)
An amphibian of the salamander tribe found in the elevated lakes of Mexico; the siredon.
  

(Ambystoma mexicanum): Literally meaning water monster (in Aztec), axolotl is a salamander (amphibian) extensively used in the evolutionary immunogenetic studies.

ASSOLOTTO. AXOLOTL. AXOLOTI