Missouri Ponds Provide Clue to Killer Frog Disease

Sep. 25, 2013 — 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, 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.

Wading in

So Smith recruited a team of students to study the ecosystems of 29 ponds in east-central Missouri. The team assayed larval amphibians for chytrid, collected physical and chemical data, and identified amphibian, macroinvertebrate and zooplankton species living in the ponds.

"I was half expecting it to be just an absolute mess, that there would be no distinguishing characteristic about ponds that have chytrid or ponds that don't," he said. "But instead, we found that the ponds that had chytrid were consistently more similar to one another than the ponds that didn't have chytrid in many different measures."

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