ScienceDaily (Aug. 17, 2011) — An international team of researchers has completed the first major survey in Asia of a deadly fungus that has wiped out more than 200 species of amphibians worldwide. The massive survey could help scientists zero in on why the fungus has been unusually devastating in many parts of the globe -- and why Asian amphibians have so far been spared the same dramatic declines.
The disease chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis or Bd, is the culprit behind amphibian extinctions in Central, South and North America, Australia and Europe. The new Asian survey of the fungus, which was published Aug. 16 in the journal PLoS One, shows that Bd is prevalent at very low levels in the region.
Asia is home to a highly diverse set of amphibian species, and potentially could be vulnerable to Bd. But Vance Vredenburg, assistant professor of biology, said very little is known about the fungus and its impact on the health of amphibians in Asia.
"That's why we're excited about this first really big survey," said Vredenburg, who led the research team. "If you look at chytrid worldwide, Asia's been the black hole in our data."
From 2001 to 2009, Vredenburg and his colleagues surveyed more than 3,000 amphibians -- mostly frogs -- from 15 Asian countries, swabbing the toe webbing, thigh and abdomen of the animals to pick up any signs of Bd, which infects the skin of amphibians.
They found that the prevalence of Bd was very low throughout the region, appearing in only 2.35 percent of the frogs. The Philippines, Kyrgyzstan, Laos, Indonesia, Malaysia and South Korea were the only countries with any Bd infection.
The survey suggests that Bd is either emerging in Asia, or may have been in Asia at low levels for a long time or that some other factor is preventing Bd "from fully invading Asian amphibians," the researchers write.
Each site in the study was only surveyed once, Vredenburg explained, so it's difficult to determine whether Bd infections in the countries are newly expanding. It will be critical, he said, "to see how Bd prevalence is changing through time, because this is key to understanding the ultimate outcome of the disease."
If Bd has been in Asia for a long time, researchers would like to know why amphibians there have managed to co-exist with a fungus that has proved so destructive elsewhere. It is possible, for instance, that Asian amphibians might bear some sort of bacterial protection against Bd in their skins.
Other scientists are analyzing the genes of the Bd fungus collected globally, Vredenburg said, "to find out whether strains from different parts of the world also differ in their virulence."
Vredenburg said the possibility of another wave of extinctions highlights the need to follow the Asian survey with further research to answer all of these questions.
And if Asia is on the brink of a chytrid epidemic, Vredenburg and colleagues think it might start in the Philippines. "The prevalence and intensity of Bd infection is much higher here than anywhere else in Asia," he said. "Bd in the Philippines today looks similar to Bd in early outbreaks in California and South and Central America."
"This study is the first important step to understanding Bd in Asia," Vredenburg said. "It provides a solid foundation that future studies can build upon."
I hope something can be done to help the frogs. I wonder what is causing the fungus?
WE'RE NEXT....EVERY SCIENTIST AGREES.
Very interesting and somewhat scary article, Teresa. Thanks for posting this important information.
Tried to send you a green star Siouxz, but couldn't so am sending hugs and to you all. Sorry I've been away but I've been Co-Hosting "Thundering Hoofs Equine Group" for now as Owner is MIA. Also Furnace breaking down, so busy and let's not forget the storms every other day. So tired. Yes, Siouxz, you got it right. That was the Concept behind the Title I made. (FrogsRus) because they have Porous Skin like us. And if they are in trouble then we are next. Bingo! You guys keep up the good work. I send prayers and love to all my friends. Goodnight, Dottie says woofs.
Got some of this from your link Teresa. Thanks for posting a very important and interesting Topic!
Bd infects the skins of amphibians such as frogs, toads, salamanders and newts and is thought to interfere with their ability to absorb water. More than 140 species of amphibians are known to be affected by it. Some are very susceptible and die quickly while others, which are more resistant, are carriers of the pathogen. One lucky species, the common British frog (Rana temporaria), appears to be completely resistant to Bd.
The Common Frog, Rana temporaria also known as the European Common Frog or European Common Brown Frog is found throughout much of Europe as far north as well north of the Arctic Circle in Scandinavia and as far east as the Urals, except for most of Iberia, southern Italy, and the southern Balkans. The farthest west it can be found is Ireland, where it has long been thought erroneously to be an entirely introduced species.