Meeting Abstract

93.5  Wednesday, Jan. 7  Effects of Batrachochytrium dendrobatidis Infections on Larval Foraging Performance VENESKY, M.D.*; PARRIS, M.J.; The University of Memphis mvenesky@memphis.edu

There is evidence of pathogen induced modifications in host behavior, including alterations in foraging behavior or foraging efficiency, which may compromise host fitness indirectly by reducing growth and development. Chytridiomycosis is an infectious disease of amphibians caused by the pathogenic fungus Batrachochytrium dendrobatidis (Bd) and has played a role in the worldwide decline of amphibians. In larval anurans, Bd infections may result in reduced developmental rates; however, the mechanism(s) responsible for these changes are unclear. We examined the effects of Bd on larval foraging time and efficiency of Grey Treefrogs (Hyla chrysoscelis) and Fowlers Toads (Bufo fowleri). If Bd infections reduce activity, we predicted that infected larvae will spend less time foraging compared to non-infected larvae. Additionally, if Bd induced oral deformities inhibit foraging efficiency, we predicted that infected larvae will forage less compared to non-infected larvae. To test these hypotheses, we conducted two experiments that ran concurrent with each other. In the first experiment, we tested for differences in foraging activity. In a second experiment, we tested for differences in the short-term ingestion rates by examining the amount of food in their alimentary track after a 3 hour foraging period. We found that in both species, infected larvae forage less often and were less efficient at obtaining food than non-infected larvae. However, we found interspecific differences in when Bd affected their performance. These data suggest that reduced larval growth rates observed in previous experiments with these species may be from Bd induced changes in foraging ability.