Axolotl Ambystoma mexicanum

The Axolotl is a most unusual animal. A salamander, it has evolved to remain in its larval stage throughout its life. Since it lives only in one high altitude freshwater lake - Lake Xochimilco in Mexico City - it does not need to metamorph into an adult to live on land and keeps its gills and baby-like features all its life.

Because it retains these larval attributes, it is able to regenerate lost limbs and damaged body parts. However, it also reproduces young itself in this larval stage.

Albino and leucistic individuals are common in captivity.

The Axolotl is critically endangered in the wild, threats including reduction and pollution of the lake (it also previously lived in Mexico City's Lake Chalco before that was drained to reduce flooding of the city), introduction of foreign fish which eat its young and its prey, and hunting by humans for food and the pet trade.

It can grow to over a foot long (45cm).