Varying Responses of Northeastern North American Amphibians to the Chytrid Pathogen Batrachochytrium dendrobatidis

Chytridiomycosis, caused by Batrachochytrium dendrobatidis (Bd), is widespread among amphibians in northeastern North America. It is unknown, however, whether Bd has the potential to cause extensive amphibian mortalities in northeastern North America as have occurred elsewhere. In the laboratory, we exposed seven common northeastern North American amphibian species to Bd to assess the likelihood of population-level effects from the disease. We exposed larval wood frogs (Lithobates sylvaticus.) and postmetamorphic frogs of six other species to two different strains of Bd, a northeastern strain (JEL404) and a strain that caused die-offs of amphibians in Panama QEL423), under ideal in vitro growth conditions for Bd Exposed American toads OVnaxyrus americanus) all died; thus, this species may be the most likely to die from Bd-caused disease in the wild. Both Bd strains were associated with mortalities of wood frogs, although half the metamorphs survived. The Bd strain from Panama killed metamorphic green frogs (L · clamitans), whereas the northeastern strain did not, which means novel strains of Bd may lead to death even when local strains may not. No mortality was observed in f our species (bullfrogs [L · catesbeianus], northern leopard frogs [L. pipiens], spring peepers [Pseudacris crucifer], and blue-spotted salamanders [Ambystoma laterale]) and in some individuals of green frogs and wood frogs that we exposed. This finding suggests these six species may be Bd vectors. Our results show that systematic exposures of amphibian species to Bd in the laboratory may be a good first step in the identification of species susceptible to Bd-caused declines and in directing regional conservation efforts aimed at susceptible species. La quitidriomicosis, causada por Batrachochytrium dendrobatidis (Bd), está ampliamente extendida entre anfibios de Norteamérica. Sin embargo, se desconoce si Bd tiene el potencial para provocar mortalidades extensivas de anfibios en el noreste de Norteamérica como ha ocurrido en otros lugares. En el laboratorio, expusimos a siete especies comunes de anfibios de Norteamérica a Bd para evaluar la probabilidad de efectos de la enfermedad a nivel población. Expusimos larvas de Lithobates sylvaticus y ranas posmetamórficas de otras seis especies a dos cepas de Bd diferentes, una cepa nororiental JEL404) y una cepa que causó muerte de anfibios en Panamá JEL423), bajo condiciones de crecimiento in vitro de Bd ideales. Todos los individuos de Anaxy