Sunday, July 21, 2013

Axolotl - Mexican Salamander

This "baby" lays eggs...

Normal vertebrate amphibians, such as frogs, emerge from the water as adults.  However, the axolotl (also know as the Mexican Salamander) spends its whole life underwater, like a four-legged fish.  In addition to that, it remains in its larval or "baby" stage.  This does not, however, prevent reproduction of young larvae.  One may ask, how can this be?  The Mexican Salamander revealed its secret a long while back, when it was raised at the Paris Zoo.  With the change in environment some of the axolotls lost their eggs, changed color, and became salamanders - adults at last!  Everything was clear...  The axolotl is, in fact, a salamander that never reaches its adult form, at least in outward appearance.  Its internal organs, however, including those concerned with reproduction, develop normally.  The case of the Mexican Axolotl is not unique.  In other species of salamander, the same situation applies.

A sexually mature adult axolotl, at age 18–24 months, ranges in length from 6 to 18 inches, although a size close to 9 inches is the most common and any length greater than 12 inches is rare.  These swimming creatures are very interesting to look at, to say the least.  I'll provide an image in a moment, from Wikipedia.  If you would like to see more of this little four-legged fish, simply perform an 'image search' using your favorite search engine by using either one or both of its name variations.

The natural habitat of axolotls is confined to lakes near Mexico City.  The young feed on plankton, then on daphnia (small water fleas).  As adults, they prey on worms, small crustaceans, and even injured fish.  At the time of reproduction, the male does a sort of nuptial dance to attract the female.  The male Mexican Salamander then deposits his sperm in a small sac at the bottom of the lake, and the female takes it up.  A week later she lays 200 to 600 eggs, which hatch two or three weeks after that.

As of 2010, wild axolotls are near extinction due to urbanization in Mexico City and polluted waters. Non-native fish, such as the African tilapia and Asian carp, have also recently been introduced to the waters. These new fish have been eating the axolotls' young, as well as its primary source of food.  The axolotl is currently on the International Union for Conservation of Nature's annual Red List of threatened species.


Image Source:  http://en.wikipedia.org/wiki/Axolotl

---End of Post "Axolotl - Mexican Salamander"

Related Blog Post:  "Anglerfish - A fish that fishes..."

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