Something is killing frogs all over the world—or maybe it is many things that are responsible for the widely observed but for the most part poorly documented declines in amphibian populations. Biologists have blamed acid rain, the pollution or eradication of wetlands, and the shrinking ozone layer, but they have found solid evidence in only a few cases. This past year yet another suspect turned up in Panamanian frogs: a previously unknown parasite.
Karen Lips, a biologist at St. Lawrence University in Canton, New York, has been studying tree frogs in the Fortuna Forest Reserve in Panama for the past seven years. During this past year she came across countless dead or dying frogs. She collected and preserved 50 frogs of 10 species and sent them to D. Earl Green, a veterinary pathologist in Maryland.
When Green examined the frogs under a microscope, he saw that their skin had swollen, ...
