A Deadly Fungus Is Wiping Out Frogs and Toads—But Some Can Develop Resistance

Scientists hope it might be possible to develop a vaccine to the fungus, based on the frog and toad’s immunity

Photo: Tom Spinker

More than a third of the planet's 6,000 species of amphibians are faced with imminent extinction, thanks in part to a deadly chytrid fungus that fatally infects those animals' skin and then impacts their ability to fight off other diseases, the Guardian reports. But researchers have recently discovered that some species of amphibians can develop a degree of resistance to the otherwise deadly disease when exposed to it under laboratory conditions. 

Researchers from the University of South Florida decided to test field reports hinting that some amphibians might have developed a degree of natural immunity to the fungus, The New York Times writes. They infected Cuban tree frogs with the fungus, then cured the amphibians of the diseases by placing them in a tank kept at 86 degrees for ten days. (The fungus dies if it gets too warm.) When the frogs were exposed to the fungus again, some of them were able to fight it off and to survive, and that immunity only became stronger as the team repeated the exposure events. 

In another experiment, the Times continues, they allowed oak toads to explore a tank containing two chambers, one laced with the fungus and another free from fungal spores. The toads hopped all around, picking up the disease. After the researchers cured them with heat, however, they found that the toads were much more likely to avoid the chamber containing the fungus. In other words, they seemed to have developed behavioral resistance. 

Currently, the Guardian explains, the only option conservationists and herpetologists have for keeping amphibians safe from the fungus is to remove them from their habitat entirely, then raise them in captivity until it's safe for them to return to the wild (assuming that ever happens). 

The hope now, the Times explains, is that it might be possible to bestow individual animals with immunity, then release them back into the environment where they will either avoid areas with the fungus or be able to fight it off. Another idea, though less likely to work, the researchers told the Times, is to develop some sort of vaccine to administer directly to animals in the wild. 

Get the latest stories in your inbox every weekday.