New Skin-eating Fungus Identified as Culprit Behind Drop in Salamander Populations

Researchers have identified a new species of fungus as the culprit behind a sharp decline in the population of fire salamanders in the Netherlands.

The salamanders, which are easily recognizable based on their yellow and black skin patterns, were first found to be dying off in the country's forests starting in 2010, with the population falling to around just 10 individuals, or less than 4 percent of original levels.

However, not until a group of scientists isolated a new species of fungus from the dead animals were they able to determine what was behind the rapid decline.

The fungus, which they have named Batrachochytrium salamandrivorans, meaning "salamander-eating," can be passed between salamanders by direct contact and possibly indirect contact as well, although this has yet to be proven. According to the researchers, once the fungus invades the animal's skin, it destroys it completely.

The discovery, according to those behind it, is one more example of the threat fungi pose to biodiversity worldwide. For example, a species related to the new fungus, called Batrachochytrium dendrobatidis (Bd), is believed to have wiped out more than 200 species of amphibians across the globe.

According to the study's lead author, An Martel from the University of Ghent, "In several regions, including northern Europe, amphibians appeared to be able to co-exist with Bd. It is therefore extremely worrying that a new fungus has emerged that causes mass mortalities in regions where amphibian populations were previously healthy."

As to why the outbreak of the new fungus is occurring now is unclear, says co-author Matthew Fisher from Imperial College London, though one possibility is that it invaded the Netherlands from somewhere else.

"We need to know if this is the case, why it is so virulent, and what its impact on amphibian communities will be on a local and global scale," Fisher said. "Our experience with Bd has shown that fungal diseases can spread between amphibian populations across the world very quickly. We need to act urgently to determine what populations are in danger and how best to protect them."

Thus far the group has tested 100 salamanders from Belgium with a new diagnostic tool the group developed. Based on the results, the researchers say there is no sign the fungus has spread beyond the Netherlands.