Scientists say tadpole disease threat to frogs worldwide

Some scientists say falling populations of amphibians and other animals suggest the Earth is undergoing a sixth so-called ‘mass extinction event’


Photo: Ananda Banerjee
Photo: Ananda Banerjee

London: Tadpoles are contracting a new, highly infectious disease that may be threatening frog populations worldwide, British scientists have found.

A parasitic disease caused by single-celled microbes known as “protists” was found in the livers of tadpole samples taken from six countries across three continents, the scientists said in a study published in the Proceedings of the National Academy of Sciences Journal on Monday.

The disease, which was found in both tropical and temperate sites, is a distant relative of oyster parasites, they said.

“Global frog populations are suffering serious declines and infectious disease has been shown to be a significant factor,” said Thomas Richards of Exeter University, who co-led the study.

The purple dots are stained parasites that have now turned up in frogs and tadpoles worldwide and is just one more threat for an already declining amphibian population. Photo: AP/University of Georgia./Michael J. Yabsley
The purple dots are stained parasites that have now turned up in frogs and tadpoles worldwide and is just one more threat for an already declining amphibian population. Photo: AP/University of Georgia./Michael J. Yabsley

“We now need to figure out if this novel microbe causes significant disease and could be contributing to the frog population declines.”

Amphibians are among the most threatened of all animal groups. In 2008, 32% of frog species were categorised as threatened or extinct and 42% were listed as in decline.

Some scientists say falling populations of amphibians and other animals suggest the Earth is undergoing a sixth so-called “mass extinction event”, with extinctions happening so fast they rival the decline and death of the dinosaurs in just 250 years. Reuters