The aquatic fungus has led to the extinction of several species of amphibians, which spend part of their life cycle in water. Now he is threatening ground amphibians.

Brazilian scientists, supported by the Sao Paulo Research Foundation FAPESP, have identified unprecedented mortality among saddle or pumpkin toads. These tiny animals inhabit the rainforests of the Atlantic Ocean. The animals were seriously infected with chytrid (Batrachochytrium dendrobatidis), which causes chytridiomycosis.

Chytridiomycosis is an infectious disease in amphibians caused by a nonhyphalous zoosporic fungus.

A study published in the journal Biological Conservation found the fungus also poses a threat to land-breeding amphibians. At the same time, animals, which play an important ecological role, suffer from it. For example, they eat insects that transmit diseases such as Dengue fever, yellow fever, and Zika virus. Decreases in amphibian populations due to B. dendrobatidis infection have already been linked to outbreaks of malaria in the 1990s and 2000s in Panama and Costa Rica.

“The fungus affects the skin of an amphibian. The infection causes a physiological imbalance and the animal eventually dies of a heart attack, ”says Diego Moura-Campos, the first author of the scientific article. The study was carried out under the auspices of the project “Chitrid mushroom in Brazil: origins and consequences”.

Previously, scientists have studied the fungus from different angles, but they rarely managed to see animals that died from a fungal infection in the wild. This is the first study to demonstrate this phenomenon in Brazil.

Now the fungus is especially dangerous for species that breed on land (there are no tadpoles and fully formed miniature adults hatch from eggs). Aquatic species may have been in contact with the pathogen longer and may have developed some semblance of immunity to infection.

The mushroom originated in Asia, on the Korean Peninsula, and probably spread throughout the world as a result of the frog meat trade in the early 20th century. It has already caused a decline in populations of at least 501 amphibian species worldwide. In Brazil alone, at least 50 species were affected, 12 became extinct and 38 declined.