Neoteny
Also called: Paedomorphosis · Neotenic
Neoteny is when an amphibian keeps its juvenile, gilled, fully-aquatic body for its whole life instead of metamorphosing onto land — the axolotl is the classic example.
A neotenic (or paedomorphic) salamander becomes sexually mature and breeds while still in its "larval" aquatic form, keeping its feathery external gills and living in water for life. It is not a stage the animal is waiting to grow out of — it IS the adult.
This is why a healthy pet axolotl never "turns into" a land salamander, and why you should never try to force it to. Some related species (like tiger salamanders) do metamorphose; axolotls normally do not.
