Meeting Abstract
48.1 Thursday, Jan. 6 Ectoparasitism, Innate Immunity, and Stress Physiology of Eastern Hellbenders (Cryptobranchus alleganiensis) from Stream Reaches with Differing Habitat Quality HOPKINS, W.A.*; DURANT, S.E.; MOSER, W.E.; VA Tech; VA Tech; Smithsonian Institution hopkinsw@vt.edu
Much like other vertebrates, habitat loss and degradation is perhaps the greatest direct threat to many amphibian populations around the world. In addition to depriving amphibians of physical habitat requirements (e.g., shelter), habitat modification may also affect the health of amphibians and potentially precipitate interactions with other deleterious factors such as pathogens, contaminants, and invasive species. The current study was designed to provide background information about the physiological state of eastern hellbenders (Cryptobranchus alleganiensis) experiencing different surrounding land use that influences in-stream habitat quality. Hellbenders are one of the largest amphibians in the world and have recently experienced dramatic population declines. Habitat degradation and disease appear to underlie some hellbender population declines. When comparing hellbenders from a stream reach with greater anthropogenic disturbance to a more forested site, we found baseline and stress-induced plasma levels of corticosterone, as well as innate immune responsiveness (i.e., blood killing ability), were similar in the two areas. Males consistently had higher plasma corticosterone levels than females, a finding consistent with the territorial activities of males early in the breeding season. Moreover, we discovered a high incidence of parasitism by leeches in the more agriculturally-impacted site. Morphological analyses confirm that the leech is the same species commonly found in declining Ozark hellbender populations in Missouri, but this parasite has never been documented east of the Mississippi River. We discuss several hypotheses as to why this parasite is found in our study system and the potential health implications for hellbenders.
