Darwin’s frogs are likely extinct and scientists are blaming a deadly fungus. Researchers determined the amphibian fungus started impacting the frogs in the 1970s. By 1982, the frogs disappeared.
The frogs are named for Charles Darwin, who discovered the species in 1843. They are unique, as the males carry their young until they are fully developed. The tadpoles are kept inside the male’s enlarged vocal sac until they are developed enough to survive on their own. As reported by BBC, they “give birth” by spitting the tiny frogs out of their mouth.
The unusual frogs are also known for their shape, which is used as a defense mechanism. When threatened, they lie on their back and play dead. Their coloring and shape resemble fallen leaves.
There are actually two species of Darwin’s frogs; the Rhinoderma rufum and the Rhinoderma darwinii. The Rhinoderma rufum, or northern species, is thought to be extinct. The Rhinoderma darwinii, or southern species, is not extinct. However their numbers are declining at an alarming rate.
Mother Nature Network reports that both species were devastated by the same fungus. The chytrid fungus destroys the frogs immune cells. As the infection spreads throughout the skin’s surface, it interferes with absorption and secretion. The frogs eventually die, as their systems cannot properly function.
Researchers believe the fungus was spread by African clawed frogs. In the 1800s, the African frogs were transported to the region to be used as pregnancy tests. When injected with the urine of a pregnant woman, the frogs would spontaneously lay eggs. Although they were helpful for women, the frogs may have infected native amphibian species with the fungus.
The International Union for Conservation of Nature said the chytrid fungus is “the worst infectious disease ever recorded among vertebrates in terms of the number of species impacted and its propensity to drive them to extinction.”
Darwin’s frogs are fascinating amphibians with interesting methods of protecting themselves and their young. Unfortunately, they are being killed off by an aggressive and devastating fungus.