Introduced Mediterranean painted frogs (Discoglossus pictus) are possible supershedders of the fungus Batrachochytrium dendrobatidis in Catalonia (NE Spain)

Abstract

In 2020 and 2021 we detected in Catalonia (NE Spain) six new episodes of mortality or presence of dying specimens in introduced Mediterranean painted frogs (Discoglossus pictus). All affected individuals were positive to the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd). Histological examinations showed intense involvement of the superficial layers of the epidermis and qPCR analyses yielded infection loads greater than 100 000 genomic equivalents of zoospores. These results suggest that this introduced species could behave as a Bd ‘supershedder’, and recommend to control its expansion due to its important role in the dynamic of chytridiomycosis.