Proceedings of the society for research on Amphibians and Reptiles in New Zealand

Chytridiomycosis, caused by amphibian chytrid fungus, Batrachochytrium dendrobatidis, infects the keratinised layer of the stratum corneum in adult amphibians. Batrachochytrium dendrobatidis is suggested to cause amphibian morbidity and mortality by disrupting the function of the skin for osmoregulation or respiration, or by the release of toxins. We investigated whether, under conditions of stress, chytridiomycosis altered water balance or metabolic rate of experimentally infected Southern bell frogs, Litoria raniformis. Frogs exhibited symptoms of chytridiomycosis for 1 week after they had been infected with B. dendrobatidis zoospores. Rehydration was significantly inhibited, but metabolic rate was not altered. Five months after L. raniformis were infected with B. dendrobatidis, all but one of the infected frogs had survived and all surviving frogs were still infected. Yet, control and infected subjects showed no difference in water balance or metabolism. The lack of difference in these physiological responses between control and B. dendrobatidisinfected frogs does not support the hypothesis that chytridiomycosis affects amphibian skin function.