Salamanders are the only terrestrial vertebrates that possess the remarkable ability to regenerate limbs or tails. The vast majority of research on vertebrate regeneration is based on the axolotl and has provided great insights on regenerative mechanisms. But how does regeneration proceed in other salamanders with different ecologies and life strategies, and which features are shared or variable?

The axolotl (Ambystoma mexicanum), a salamander native to Mexico, is known for its impressive ability to repeatedly regenerate injured or lost organs and body parts, including parts of the brain, eye, spine, and heart, as well as parts of the tail and complete limbs. The field of regeneration biology is trying to uncover the mechanisms underlying this amazing capacity and for that the axolotl has become the vertebrate model organism over the past hundred years. However, as a so-called neotenic salamander the axolotl is quite special in that it spends its entire life in the water while retaining a number of typical larval characteristics such as external gills and a paddle-shaped tail even as a mature adult.