Chytridiomycosis - Research

Research

Laboratory studies suggest that the fungus performs poorly above 28 °C (82 °F), and that exposure of infected frogs to high temperatures will kill the fungus. This may explain why chytridiomycosis-induced amphibian declines occur primarily in cool regions, like mountain chains where the cloud cover is apparently more abundant than in the warmer jungle regions. However, conflicting research does exist. It has been shown that naturally produced cutaneous peptides can inhibit the growth of B. dendrobatidis when the infected amphibians are around temperatures near 10 °C (50 °F), allowing species like Rana pipiens, the northern leopard frog, to clear the infection in about 15% of cases.

Although many declines have been credited to the fungus B. dendrobatidis, there are species that resist the infection and some reports have found that some populations can survive with a low level of persistence of the disease. In addition, some species that seem to resist the infection may actually harbor a non-pathogenic form of Batrachochytrium dendrobatidis.

Some researchers contend that the focus on chytridiomycosis has made amphibian conservation efforts dangerously myopic. A review of the data in the IUCN Red List found that the threat of the disease was assumed in most cases, but that there was no evidence that it is, in fact, a threat. Conservation efforts in New Zealand continue to be focused on curing the critically endangered native Archey's frog, Leiopelma archeyi, of chytridiomycosis even though research has shown clearly that they are immune from infection by B. dendrobatidis and are dying in the wild of other still-to-be identified diseases. In Guatemala, several thousands of tadpoles perished from an unidentified pathogen distinct from B. dendrobatidis. Such researchers stress the need for a broader understanding of the host-parasite ecology that is contributing to the modern day amphibian declines.