Tadpole Slayer: Mystery epidemic imperils frogs
By Janet Raloff
From Alaska to Florida, a novel and yet-unnamed protozoan is knocking off tadpoles. Species vulnerable to “the beast” belong to the genus Rana, which includes leopard frogs, green frogs, and bullfrogs, says ecologist John C. Maerz.
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His team at the University of Georgia in Athens stumbled across mass die-offs of southern leopard frog tadpoles in nearby ponds last year. Dissection showed the animals’ innards peppered with spherical, one-celled parasites. Genetic testing confirmed these are loosely related to Perkinsus, a disease-causing organism that affects marine shellfish.