In India a frog gives birth to a fungus. Scientists have never seen anything like this

(CNN) — Observing a flock of golden-backed frogs in a roadside pond in Karnataka, India, a group of naturalists noticed something strange about one of the amphibians: A small fungus was growing on the side of the animal.

How the apparently healthy frog evolved its fungal companion has never been recorded before, according to a note published in January in the journal Reptiles & Amphibians, which has baffled scientists.

“When I first saw the frog with the fungus, I was astounded and amazed by it,” Lohit YT, a river and wetland specialist at the World Wildlife Fund India in Bengaluru, said via email. YT was part of the group that discovered the frog. “My idea was to document it, because this phenomenon is something we had never heard about. “We just hoped that this was a rare occurrence and not a dangerous event for the frog.”

This species is known by the scientific name Rao Intermediate Golden-backed Frog or Hilarana Intermedia, found in abundance in the states of Karnataka and Kerala in southwestern India. The frogs are small, measuring only 7.4 centimeters long.

As the naturalists watched the frog grow the fungus, the animal moved away from the center of the branch it was sitting on, turning and changing position, but the fungus remained completely in place, YT said. The group did not touch the frog.

YT said, the frog moved from the center of the branch it was sitting on to the tip, turning and changing its position, but the mushroom remained exactly in place. (Credit: Lohit YT)

The authors discovered the amphibian in June 2023 and did not collect it, so neither the cause of the incident nor the fate of the frog are known.

But through imaging, mycologists later identified the fungus growing on the frog’s flank as a common bonnet, part of the genus Mycena, a type of fungus that grows primarily on the rotting wood of dead trees. , the authors wrote in the published article. The fungus is a saprotrophic decomposer that typically obtains its nutrients from dead or decaying organic matter, but a 2023 study found that it may have evolved to thrive on living plants as well.

A 2023 study further suggested that Mycena fungi may have evolved to form a symbiotic relationship with living plants or trees, meaning that both the plant and the fungus growing on it would benefit from this arrangement: the fungus would receive nutrients. Will take and transfer them. Host plant. The authors said that Mycena may be useful in pruning dead branches in trees.

The prognosis of frogs with polyzoant fungus is unknown, but there are several theories about the cause of the condition.

Mushroom Frog’s Fate

Alyssa Wetterau Cagner, a postdoctoral associate in the department of public and ecosystem health at Cornell University’s College of Veterinary Medicine, found the discovery fascinating when she first reported the fungus attached to the frog’s flank.

“Fungi are dynamic organisms that adapt to changes in their environment, and when exposed to new potential hosts in different environments or climates, they can evolve in places we previously expected,” he said in an email. Wasn’t.”

Although it is difficult to predict the frog’s fate without studying its condition, it is possible that “a healthy frog can withstand mild colonization of its skin by this fungus without any adverse health effects,” Cagner said. However, fungal infections are very common in frogs, and if the fungus “grows extensively on the skin or burrows into the animal’s body, the frog may develop symptoms of fungal disease,” he said. Kagner was not involved in this discovery.

There are many types of fungi that can infect frogs, and fungus-frog interactions are still to be discovered. Frogs with signs of fungal disease, such as “altered frog behavior” or “skin damage including ulcers or tumor-like nodules”, have an infection that can often lead to the death of at least some infected animals. Cagner said.

Anything out of the ordinary, including such fungal growth, is a cause for concern for the frog species, said Karthikeyan Vasudevan, chief scientist of the Endangered Species Conservation Laboratory at the Center for Cellular and Molecular Biology in Telangana. Vasudevan was not involved in this discovery and he too was surprised by this discovery.

“Sick animals have very little chance of survival in the wild. It is difficult to detect a sick animal, as it quickly dies or is eaten. Therefore, something like this is interesting and should be further observed and tested in frogs,” Vasudevan said in an email.

Initially, Vasudevan thought that the fungus stuck to the frog’s skin rather than growing, but photographs of the creature convinced him otherwise. “In fact, it is a case of a living fungus on a living frog,” Vasudevan said. “But one of the possibilities is that there was a small piece of wooden debris under the frog’s skin and a fungus had grown from it.”

a disease caused by fungus

India is currently facing an epidemic of a frog-killing disease called chytridiomycosis, a fungal infection that affects more than 700 amphibian species worldwide. The authors of the new note write that the disease has been seen at low levels in all frog hotspots across India.

Chytrid disease is an example of a common interaction between amphibians and fungi. But the authors don’t know whether this is related to this finding, YT said.

“This specific type of fungus is not closely related to the fungal species that causes chytridiomycosis, so I’m not concerned that this fungus is a direct indicator of chytridiomycosis,” said Cagner, who studies the disease. “However, it is possible that susceptibility to chytrid infection may have changed in the Mycenaean frog.”

He added that the frog that has the fungus on its side may be more susceptible to chytridiomycosis by being compromised by the Mycena, or it may be more immune “because the Mycena has reprogrammed the frog’s immune system.”

“We have no expectations of chasing the frog because it is not a common occurrence,” YT said. The authors will visit the site again during the next monsoon season, when the weather will be warmer and rainier and frogs will be more abundant. , , He added.

“If we could find it, that would be great,” YT said. This place has been visited by enthusiasts and experts alike. It would be wonderful if a researcher got hold of it and could move the investigation forward, but again, that is very unlikely to happen.