Occurrence of chytrid fungus (Batrachochytrium dendrobatidis) and body condition in syntopic water frogs Pelophylax shqipericus and P. ridibundus

Abstract

We studied the presence of chytrid fungus Batrachochytrium dendrobatidis (Bd) infection in two syntopic water frogs Pelophylax shqipericus and P. ridibundus in a sample population from southern Montenegro. In total, 45 and 34 adult specimens of P. shqipericus and P. ridibundus, respectively, were tested for Bd infection. Here, the infection was confirmed for the first time in P. shqipericus, a vulnerable endemic species of the Balkans. There was a greater proportion of infected specimens in P. shqipericus than in P. ridibundus (15.6% and 2.7%, p < 0.05, respectively). Males and females did not significantly differ in Bd prevalence both within species or at genus level. Infection intensity was low in both species and body condition did not differ between infected and non-infected specimens. However, P. shqipericus had significantly lower body condition index than P. ridibundus in general, indicating elevated exposure to environmental stress in a comparison with congeneric species. The emergence of the pathogenic Bd fungus in the small-range threatened water frog species is worrying and indicates the need for close monitoring, urgent risk analysis, and population health assessment.