BELDEN, L.K.*; RUBBO, M.J.; L�PEZ, M.; RAFFEL, T.R.; MIRZA, R.S.; KIESECKER, J.M.; Virginia Polytechnic Institute and State University; Pennsylvania State University; Pennsylvania State University; Pennsylvania State University; Pennsylvania State University; Pennsylvania State University; ; : Effects of Aeromonas hydrophila exposure on wood frog tadpoles and juveniles

Like all organisms, amphibians are host to a wide array of pathogens and parasites. However, despite the ubiquitous nature of pathogens and parasites, we have a poor understanding of the ecological consequences of infection. To begin to understand the effects that exposure to potential disease causing organisms might have on amphibians, we completed two experiments involving exposure of wood frogs, Rana sylvatica, to Aeromonas hydrophila. Aeromonas hydrophila is a common gram-negative bacteria found in freshwater systems and has been associated with stress-related outbreaks of disease in fish and amphibians. Our first experiment examined the effects of bacterial exposure on tadpole activity levels, and on their susceptibility to predation by Dytiscid beetle larvae following exposure. Activity levels did not differ with exposure status. In addition, there were not statistically significant differences in susceptibility to predation, although our data suggest that infected tadpoles might be somewhat more vulnerable and this question is probably worth pursuing further. Our second experiment addressed overwintering survival of juvenile wood frogs following Aeromonas exposure. Juvenile wood frogs that were exposed to the bacteria did not suffer greater overwintering mortality, but were significantly smaller than their unexposed counterparts the following spring, suggesting that there might be some cost to exposure.