Adaptation to captivity within ex-situ collections of urodela: from behavioural to microbial plasticity.

Amphibians are currently the animal class facing the highest risk of extinction, notably because of disease outbreaks. Faced with the urgency of the situation, conservation institutions prioritize ex-situ collections to ensure the persistence of the most endangered species. Yet, little is known about the effect of captivity on their skin microbiome, an effective barrier against pathogens responsible for chytridiomycosis. We hypothesize that captivity could restructure salamander skin microbiome and modify their behaviour, thereby weakening their in-situ fitness during reintroduction efforts.
Using two European urodela, the alpine newt, Ichthyosaura alpestris, and the palmate newt, Lissotriton helveticus, we collected adults in the wild and kept them in captivity for a year, while monitoring the evolution of their behaviour and skin microbiome monthly.
Our results suggested differences in personalities and evolution of the skin-microbiome between sexes and species. Taken together, we hope these results will provide general guidelines for conservation projects for urodeles.