JOANNE-+AXOLOTL

**Axolotl** =__**Modern Animal - axolotl **__=

**Adaptation**
Axolotl’s scientific name is Ambystoma mexicanum. It has a derived mode of development that is characterised by metamorphic failure, paedomorphosis, which isa phenotypic and/or genotypic change i n which the adults of a species retain traits previously seen only in juveniles. It leads to an adaptation for axolotl to have an entirely aquatic life cycle.

Ordinarily, amphibians undergo metamorphosis from egg to larva, which is animmature form of other animals that undergo some metamorphosis, e.g., a tadpole is a larva of a frog, and finally to ad

ult form. However, the axolotl remains in its larval form throughout its life, which means that it retains its gills and fins, and it doesn't develop the protruding eyes, eyelids or any other characteristics of other adult salamanders. It just grows much larger than a normal larval salamander. It also reaches sexual maturity in this larval stage. This state is described as "perennibranchiate". Although it does possess basic lungs, it mainly breathes with three feathery gill structures that are located on either side of the head andits skin. It is completely aquatic.

The Axolotl has the ability to regenerate and primarily the fact that it exhibits the phenomenon known as neoteny.

Neoteny is a "backward" step in evolution, as the Axolotl is descended from what were once terrestrial salamanders, for example its closely related species, the Tiger Salamander, Ambystoma tigrinum and Ambystoma mavortium spp. Through some quirk of nature and probably due to environmental conditions, a neotenous form is developed. One of the Axolotls unique adaptations is the capability of regenerating lost body parts. This can help them to survive, as they won’t lose their lives for losing small parts of their body, such as toes and tails. Without this adaptation, they may die and are not able to reproduce.

Axolotls have also adapted their means of transportation because of their aquatic life. The Axolotls retains its larval tail during neoteny. This helps to improve mobility and also helps to balance while swimming in water. Without the tail, axolotls won’t be able to swim so fast in water to catch worms, insects, and small fish, such as tubifex worms and white worms to eat, then they willstarve to death. Then, they won’t be able to reproduce.

Thefour limbs and tail with crest allow them to have a better control in balancing and changing direction when swimming. If they do not have the four limbs and the tail, they would not be able to swim fast when catching food, so they will starve and die, or even they may lose balance and crash into stones or other sea creatures in the sea then die, which then they cannot reproduce.

Gills are adapted too. Grills allow axolotls to breathe in water instead of using their basic-developed lungs. Lungs cannot function under water, therefore, without the grills, axolotls won’t be able to stay in water for a long time, which may cause them an inconvenience when searching for food as they are not able to stay in water for too long. If they do not have enough amount of food, they may starve to death, which then they cannot reproduce.

Axolotls have their sensory organs located along the sides of their head and trunk, they help them to find food by smell and by their lateral line organs as they do not have good eyes. Without this adaptation, they won’t be able to find food or crash into stones or other sea creatures, as they cannot see properly with their eyes. They may die as a result, and cannot reproduce.



(The red line below each animal represents roughly 2 mm. )

Stage 1 : The egg is typically amphibian. Then It comprises of the embryo which is around 2 mm in diameter, including the surrounding layers of jelly.

Stage 2 : The embryo prior to hatching. It is approximately 11mm in length at this stage.

Stage 3 : the young larva is developed, prior to the growth of limbs. Larval axolotls tend to be transparent until their skin has thickened. The pigment cells have proliferated over the body, so the organs are seen outside the skin. Stage 4: After approximately two weeks, the front legs develop first, the then hind legs grow a few weeks later. Stage 5: the axolotl becomes a miniature adult. The average size is about 23-25 cm. Adult axolotls normally reach their full size after eighteen months to two years.



Habitat
The axolotl is native to Lake Xochimilco and Lake Chalco in Mexico.They live in water as they are completely aquatic. Axolotl’s habitat has a high altitude that is surrounded by water and land. It is very moist. These conditions are to suit neoteny.

As axolotls are "cold-blooded" just like the other amphibians, the temperature of the environment they live really affect them. They obtain their body heat from their environment, which does not allow them to be well adapted for any activity in any cold environments. Staying in warm places can help them to remain active even at quite low temperatures. The water temperature in both the lakes rarely rises above 20 °C, though there is also a possibility that it may fall to 6 or 7 °C or even lower in winter, but as they live in water, the water temperature always remain at around 20 °C, therefore, the cold temperature on the land doesn’t affect them much.

Their reproductive habit is that the female axolotls lay eggs in the water. They live in lakes. Rocks are often locations that the axolotls choose to lay their eggs.

The warm temperature allows the worms, insects and fishes to grow and live, so that axolotls can get enough food there. As the axolotls need to hunt their food in water, limbs, grills and tails are adapted. (more information, please refer back to adaptation)

= = =__Future animal of axolotl__= Wincheliose fishanneia =__Extinct animal of axolotl__= Amphibamus =__**Other animal that lives in lakes**__= Beaver = = =__Bibliography__ = //axolotl//. (n.d.). Retrieved june 20, 2011, from pkpets: [] = = //Axolotl//. ( 2011, June 12 ). Retrieved june 15, 2011, from wikipedia: [] = = //Lake Xochimilco//. (2010, August 14). Retrieved june 21, 2011, from wikipedia: [] = = Sydenham, S. & Thomas, R. (2002). //axolotl//. Retrieved june 20, 2011, from kidcyber: []