Frogs leap away from deadly disease

Sept 19, 2011: - The chance discovery of a previously thought to be extinct species of frog has led James Cook University researchers to believe amphibians may have found a way to survive a devastating and fatal infection.

The Armoured Mist frog had not been seen for 17 years when a population was discovered in 2008 in a remote area of Far North Queensland by then JCU PhD student Robert Puschendorf working with Professor Ross Alford and the University’s Amphibian Disease Ecology Group.

It was believed until then that the Amoured Mist frog had been wiped out by outbreaks of Chytridiomycosis, caused by the amphibian chytrid fungus, which has caused frog extinctions in many regions of the world.

Chytridiomycosis was believed to have caused the extinction of all known high elevation populations of seven frog species in the Wet tropics.

“But we have found that this surviving group of Armoured Mist frogs and another species, the waterfall frog, are not only infected with the disease but they are thriving,” Dr Puschendorf said.

“The big difference was that these frogs were not in their normal environment of the wet, cooler rainforests of the tropics. They were living in a drier area which, while near the rainforest, had lower rainfall and less canopy cover.”

Dr Puschendorf said that he and his fellow researchers believe that the lack of canopy cover allowed the rocks on which the frogs perched to warm up and that in turn slowed the growth and reproduction of the pathogen that causes Chyrtridriomycosis.

“We also suggest that surveys looking for apparently extinct or rare species should not be limited to what are believed to be their core environments,” he said.

The findings of the group have been published in the recent edition of Conservation Biology.

The paper’s authors are:

Dr Puschendorf, Professor Alford and Dr Jeremy Vanderwal from JCU’s School of Marine and Tropical Biology;

Dr Conrad Hoskin, JCU School of Marine and Tropical Biology and ANU’s Research School of Biology;

Dr Scott Cashins and Dr Lee Skerratt from JCU’s School of Public Health, Tropical Medicine and Rehabilitation Sciences; and

Keith McDonald from Queensland Parks and Wildlife.

Dr. Puschendorf, Professor Alford, Dr Cashins, and Dr Skerratt are all members of JCU’s Amphibian Disease Ecology Group which has led the world in discovering Chyrtridriomycosis and researching its effect on amphibians.

JCU Media Jim O’Brien 07 4781 4822 or 0418 892449

Issued: September 19, 2011