Mexican Axolotl
Ambystoma
mexicanum
The Mexican axolotl (pronounced ACK-suh-LAH-tuhl)
salamander has the rare trait of retaining its larval features throughout its
adult life. This condition, called neoteny, means it keeps its tadpole-like
dorsal fin, which runs almost the length of its body, and its feathery external
gills, which protrude from the back of its wide head.