Axolotl

The Axolotl (also known as the Mexican Walking Fish) is an unusual neotenous variety of salamander. Occurring naturally only in two lakes near Mexico City (one of which no longer exists), axolotls remain aquatic, with the form of a larval salamander, throughout their entire lifespan.

Injections of iodine, stimulating its thyroid gland, can stimulate the axolotl's metamorphosis into an adult form, which is similar, but not identical, to that of the tiger salamander. Axolotls are capable regenerating entire lost limbs if necessary, and sometimes develop extra appendages in the process. These interesting phenomena have made axolotls the subjects of intensive study, and they are also commonly kept as pets.

The axolotl is carnivorous upon small fish and invertebrates.