Sep 25, 2013
Missouri ponds provide clue to killer frog disease
Chytrid fungus known as Bd, thought to be amphibian specialist, may also lurk in invertebrates, such as insects
By Diana Lutz
The skin fungus, Batrachochytrium dendrobatidis (Bd), also known as amphibian chytrid, first made its presence felt in 1993 when dead and dying frogs began turning up in Queensland, Australia. Since then it has sickened and killed frogs, toads, salamanders and other amphibians worldwide, driving hundreds of species to extinction.
As a postdoctoral researcher Kevin Smith studied Bd in South Africa, home to the African clawed frog, a suspected vector for the fungus. When he took a position at Washington University in St. Louis, where he is now interim director of the Tyson Research Center and adjunct professor of biology in Arts & Sciences, he worked on other problems.
But whenever he visited a pond, he collected tadpoles and checked their mouth parts (often a fungal hot spot) under the microscope, just out of curiosity.
He found the fungus in about a third of the ponds whose tadpoles he checked. The obvious questions were: Why only a third? Why didn’t it occur in all amphibian populations in a region where it is found?
The amphibians and the fungus have reached an evolutionary truce in Missouri, where the chytrid is endemic rather than epidemic. Because there was no pressure to rescue an amphibian population, Smith had the time and the opportunity to look more broadly and to study the entire pond ecosystem.
Together with then-undergraduate student Alex Strauss, Smith collected physical and chemical data and surveyed the species living in 29 ponds in east-central Missouri. The results of this study are published in the Sept. 25 edition of PLOS ONE.
Read entire article at The Source.