ELICITS ACUTE STRESS RESPONSE IN SPOTTED SALAMANDERS BUT NOT INFECTION OR MORTALITY.

The emerging fungal pathogen () is a major threat to amphibian species worldwide with potential to infect many species if it invades salamander biodiversity hotspots in the Americas. can cause the disease chytridiomycosis, and it is important to assess the risk of -induced chytridiomycosis to species in North America. We evaluated the susceptibility to of the common and widespread spotted salamander, , across life history stages and monitored the effect of exposure on growth rate and response of the stress hormone, corticosterone. We conclude that spotted salamanders appear resistant to because they showed no indication of disease or infection, and experienced minor effects on growth upon exposure. While we focused on a single population for this study, results were consistent across conditions of exposure including high or repeated doses of , life-stage at exposure, environmental conditions including two temperatures and two substrates, and promoting pathogen infectivity by conditioning cultures with thyroid hormone. Exposure to high levels of elicited an acute but not chronic increase in corticosterone in spotted salamanders, and reduced growth. We hypothesize that the early acute increase in corticosterone facilitated mounting an immune response to the pathogen, perhaps through immunoredistribution to the skin, but further study is needed to determine immune responses to . These results will contribute to development of appropriate management plans to conserve species at risk of emerging disease.