Ambystoma mexicanum

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The organism that I have decided to write about this week is an amphibian with a strange genetic change from its common ancestor. Instead of metamorphosing from its larval stage so that it will live both on land and in the water it is completely aquatic and remains in its larval stage. This organism has the binomial nomenclature Ambystoma mexicanum. The more common name for this organism is the Axolotl. It was discovered in Mexican rivers that are now being imposed upon by Mexican expansion which has earned this animal a spot on the endangered species list, at least in the wild. It is used as a test subject in many scientific labs, and is also kept as a pet by many people so that in captivity at least the animal is safe from extinction. There have been some efforts to breed and release the organism back into the wild, but efforts are not very successful due to the river being imposed upon by cities so that the axolotl’s natural habitat is disappearing. The axolotl is an amphibian closely related to salamanders that stays in its larval stage for the entirety of its life. It does grow bigger than normal larval stages of similar species. It even has legs and lungs, but breathes primarily through its gills. The axolotl also does become sexually mature in this stage as well. The axolotl is carnivorous. axolotls in captivity have a slightly greater variety in color than those in the wild ranging from black, white, brown, and yellow with various shades in between. The axolotl also has another strange adaptation which is why it is used in labs in captivity. The axolotl has healing and regrowth properties greater than that of a normal organism. The axolotl is able to totally regrow limbs whereas most species cannot. this prodigious adaptation is being used in laboratories and has interested many in potential products and valuable information that could affect humans. studying the methods and adaptations of the axolotl that allows it to regrow limbs could give us a way to do it for ourselves or at least lead to products that help in tissue regrowth if not whole limbs. Scientists hypothesize that staying in the larval form could actually be a step backward for this species instead of a new adaptation. This is based on there close relation to another species of salamander that is terrestrial. Some scientists even hypothesize that the axolotl could have diverged from its close relative the tiger salamander. In order to do this some members of the species must have had the adaptation to not metamorphose, and then thrived in that condition passing on the genetic information so that this would be the norm for the species. It is possible for species to not metamorphose, but this is usually due to environmental conditions, whereas the axolotl is purely genetic. It is also possible for the axolotl to spontaneously metamorphose or for scientists to provide favorable conditions which result in metamorphosis. metamorphosed axolotl are very rare however so it is much more likely that they will only be found in captivity.

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Clare, J. P. (2000, July 1). Introduction. Retrieved September 19, 2016, from

Creighton, J. (2016, June 28). Meet the axolotl: The mexican walking fish. Retrieved September 19, 2016, from


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