Researchers from the Oregon State University and the University of Pittsburg have revealed a new study, which claims that the bullfrogs may die of the fungal infection that they had themselves spread.
The decline in the amphibian population worldwide was linked to the deadly fungus chytrid fungus, spread by bullfrogs, and it was earlier assumed that bullfrogs themselves may be resistant to this fungus, since they spread it.
This new research, on the other hand, claims that bullfrogs alone may not be responsible for the spread of this deadly fungus, and that there may be many other factors responsible for the decline in the amphibian population in the world, including climate change, invasive species, pollution, habitat destruction and increased UV-B exposure.
"At least so far as the chytrid fungus is involved, bullfrogs may not be the villains they are currently made out to be," Stephanie Gervasi, a zoology researcher in the OSU College of Science, explained. "The conventional wisdom is that bullfrogs, as a tolerant host, are what helped spread this fungus all over the world. But we've now shown they can die from it just like other amphibians."
This research further suggests that bullfrogs are actually not very good hosts for this fungus, and the reason why this fungus has spread so fast is yet to be known.
Andrew Blaustein, professor of zoology at the Oregon State University, and an international leader in amphibian studies, speculates that the fungal increase may be linked to climate change, which also adds to a lowered immune system function in amphibians, making them further susceptible to getting infected by the fungus.
"There are a lot of possible ways the fungus can spread. People can even carry it on their shoes," he added.
The researchers further speculate that the international trade of amphibians and other animals may cause global pathogen distribution.
This study is published in the professional journal EcoHealth.