Why are axolotls the most studied salamander model?

Axolotls are used because they provide a vertebrate model organism that is easy to rear and breed in the lab.

Methods to care for axolotls have been perfected over many decades and they are the only salamanders that can be bred multiple times a year.

Their care is simplified by the fact that axolotls do not typically undergo metamorphosis and thus have a completely aquatic life cycle. Axolotl eggs are larger than frog eggs and they are clear, so one can easily watch embryogenesis happen without need for a powerful microscope. Also, the large size makes it possible to perform surgeries on embryos to investigate questions about development, such as mechanisms that control cell fate and differentiation. The large collection of axolotls in the Ambystoma Genetic Stock Center ensures that researchers do not have to rely on salamanders collected from natural populations, which are genetically variable and susceptible to extinction by over-harvesting and pathogen transmission by collectors.

To learn more:

Voss, S.R., Epperlein, H.H., Schroeder, B., and Tanaka, E.M. 2009. The axolotl. In Emerging Model Organisms. Cold Spring Harbor Press.

Fun Facts

How many eggs can an axolotl lay at a single time?

Almost all amphibians lay between 1 and 450 eggs at a single laying.

An axolotl lays between 100 and 1000 eggs, with the number depending on the age and size of the female, and the time since the previous breeding event.