Mexicanum

Amphibians The axolotl (Ambystoma mexicanum) retains its larval form with gills into adulthood The lungs of most frogs and other amphibians are simple and balloon-like, with gas exchange limited to the outer surface of the lung.

For studies of regeneration urodele amphibians such as the axolotl Ambystoma mexicanum are used, Nacu, E. and Tanaka, E.M. (2011) Limb Regeneration: A New Development?

The changes that take place at metamorphosis are under the control of thyroid hormones and in obligate neotenes such as the axolotl (Ambystoma mexicanum), the tissues are seemingly unresponsive to the hormones.