A. mexicanum’s life cycle is rather special, since this species exhibits neoteny, which means that it retains its larval form into adulthood and becomes fertile without going through metamorphosis (Clare 2015). In the laboratory, it is possible to induce the metamorphosis by injecting thyroxin, but the metamorphosis is lethal for the organism (Khattak et al. 2014). The life of A. mexicanum is divided in five stages. As with every amphibian, the life of A. mexicanum starts as an egg, surrounded by a jelly substance. Stage 2 is an embryo just before the hatching. The axolotl becomes a young larva, still without limbs in stage 3. Their limbs will start to develop in stage 4. The axolotl’s age is now about 2 weeks. The front legs take form first, and afterwards its hind legs will develop. In the fifth and final stage A. mexicanum becomes sexually mature. It takes about two years for A. mexicanum to attain its full size (Clare 2015). Healthy axolotls can reach ages of more than ten years (Gresens 2004).
A. mexicanum reproduces sexually. Reaching sexual maturity depends on environmental conditions, but it should be between five months and two years. A female can produce over a 1000 eggs and it can spawn several times a year, but spawning too often might be at the expense of their health.
Geographic distribution (environment/habitat)
A. mexicanum has a very small habitat and is endemic to Mexico. It is only known for living in a small area near Mexico-City (see figure 2) When A.