The Axolotl

Native to only two lakes in Mexico, the axolotl is a neotenic salamander.  It's larval stage does not undergo metamorphosis so it retains it's gills and is not terrestrial.  They have no thyroid hormone which causes them to live in larval form.  They can, however be coaxed into metamorphosis with injections of iodine.  Though this shortens their lifespan from 15 years to 5.  

     Much of their body is capable of regeneration and is thus invaluable in scientific research.  This amphibian is carnivorous, eating worms, insects, and small fish.  They feed by "snapping" their jaws, inhaling whatever is in their path.  Adult axolotl's can measure up to 30 centimeters.  With large heads and small eyes and a mane of gill's projecting from the back of the head they are quite different looking than other salamanders.  These gill's are used for oxygenation of the blood although, they do sometimes gulp air into their lungs. They come in a variety of colors and make good pets.

     Reaching sexual maturity at 6-18 months the male axolotl drops 6-30 bundles of spermatophore and lures the female over one.  Once the female picks it up it will take around a few days before between 400-1000 eggs are laid onto plants.  Once laid the eggs will hatch in about three weeks.  The larger young will usually eat the smaller or deformed young as a natural selection process.

     The axolotl live in high altitude lakes in Mexico.  Natively they inhabit Lake Xochimilco and Lake Chalco.  Unfortunately Lake Chalco has dried up and Lake Xochimilco has been greatly drained to supply Mexico City.  Fish have also been added to the lakes in which the axolotl call home.  These fish feed on the larvae and eggs as well as adult animals, lowering their survival rate.  Due to the changes in it's habitat the axolotl is listed as Critically Endangered and is close to extinction in the wild.

Images from:

     http://www.reptilechannel.com/images/amphibians/axolotl-breed-500.jpg

     http://www.mexicovacationtravels.com/wp-content/uploads/2009/03/axototlpabloneco.jpg
     http://www.daviddarling.info/images/axolotl.jpg