The tadpole is a weird organism, there’s no getting around it. Unlike most animals, which start as tiny versions of their adult selves, tadpoles look like disembodied frog heads that eventually sprout disproportionately small limbs and grow into adult frogs. As though that image weren’t disturbing enough, English scientists have now identified a deadly tadpole parasite that threatens fragile, endangered frog species across the globe.
“Global frog populations are suffering serious declines and infectious disease has been shown to be a significant factor. Our work has revealed a previously unidentified microbial group that infects tadpole livers in frog populations across the globe,” said Professor Thomas Richards from the University of Exeter.
The research concerns something called a protist: Though single-celled in nature, the parasites make the most out of the one cell they have – they’re complex and store DNA in a nucleus, just like ours. These particular protists were found in tadpole livers from six countries across three continents. Tropical, temperate, it didn’t matter – multiple populations were affected, which is bad news for frogs.
“We now need to figure out if this novel microbe – a distant relative of oyster parasites – causes significant disease and could be contributing to the frog population declines,” Richards said.
Amphibians, which include frogs and toads, are among the most endangered and threatened species in the world. As recently as 2008, 32% of all amphibians were classified as either threatened or extinct – enough to cause some experts to believe that Earth is undergoing a sixth mass extinction event.