The axolotl can regenerate lost limbs and parts of several organs. This aquatic salamander is especially notable because it can regrow complex tissues, including bones, muscles, nerves, blood vessels, and skin.
Axolotls are a population of tiger salamanders native to lakes and canals around Mexico City. They commonly retain juvenile features throughout adulthood, a condition called neoteny. Their external feathery gills remain visible, even though they can also use lungs and exchange gases through their skin.
Regeneration does not mean an axolotl is invulnerable. Healing takes time, and the result depends on factors such as age, health, the location of the injury, and environmental conditions. Researchers study axolotls to understand why their cells can rebuild structures instead of forming only scar tissue.
Captive axolotls occur in many colors, including pale leucistic forms that are often sold as pets. Their popularity has also created confusion about conservation: the wild species is critically endangered because its native habitat has been heavily altered and polluted.