Over the summer, Lohit YT, a river and wetland specialist at the World Wildlife Fund-India, set out with his friends for the rainy foothills of the Western Ghats in India. They had one goal: to see amphibians and reptiles.
“There were five of us, busy searching for the species and avoiding leeches,” Lohit said.
But his herpetology search turned into a mushroom find.
Dozens of Rao’s golden-backed intermediate frogs were in a roadside pond. But the crew noticed something different about one of the frogs perched on a twig: a curious growth. Upon closer inspection, they realized it was a small mushroom growing out of the frog’s flank about the size of a thumb, like a small mushroom limb. In other words, a fungus that sprouts from a live frog.
Mr. Lohit and his friends published a note about his discovery in January in the magazine Reptiles and Amphibians.
After Lohit posted photos of the frog online, citizen scientists and mycologists weighed in to say that the hitchhiker mushroom looked like a type of bonnet mushroom. Bonnet mushrooms, collectively called Mycena, generally live on decaying plant matter, such as rotting wood. So how did one end up sprouting from a frog?
Very few fungi produce mushrooms. For a fungus to grow, a fungal spore must settle on a surface and produce mycelium. Mycelia are thread-like cells that absorb nutrients, similar to the root of a plant. If the mycelium finds enough nutrients, the fungus can produce a mushroom.
That adds to the puzzle of the mushrooms and the frog. The mycelia are found on the surface of the amphibian’s skin or deeper inside its body, said Matthew Smith, a fungal biologist at the University of Florida who was not involved in the finding. But the team did not collect the frog or the mushroom, as they only planned to observe. Therefore, it is impossible to say exactly what was happening, he said.
Scientists have discovered that in the past fungi grew where they normally should not grow, but Dr. Smith had never heard of a fungus on living animal tissue. “I was very surprised to see it,” he said.