Abstract
New pathologies are causing dramatic declines and extinctions of
multiple amphibian species. In 2013, we found fire salamanders with
undescribed cysts at the throat level in one population in Northern
Italy, which existence is not reported in amphibians yet. With the aim
of describing this novel phenomenon, we performed repeated surveys to
assess the frequency of affected salamanders from 2014 to 2020, and
integrated morphological, histological and molecular analyses. Cysts
affected up to 22 % of salamanders of the study population and started
spreading to nearby populations. Cysts are formed by mucus surrounding
cells about 10 μm long, characterized by numerous undulipodia.
Morphological and genetic analyses did not yield a clear match with any
described organism or salamander cell. The occurrence of these cysts
calls for more studies on the origin and impact on wild populations.