Axolotls are very unusual amphibians as these large salamanders are able to breed in their larval stage. Their most striking feature are the feathery gills, although they also develop lungs so often swim to the surface to take a gulp of air.
Despite being common in captivity they are listed as a critically endangered species. The wild population of axolotls is limited to waterways around Mexico City, which are prone to pollution.
They have long fascinated scientists as they are able to regenerate limbs that they lose.