Prevalence of a Chytrid Pathogen (Batrachochytrium dendrobatidis) in Eastern Hellbender Salamanders in New York and Pennsylvania

Amphibian populations are currently declining globally. There are many possible causes for these declines, among which an emerging infectious disease, chytridiomycosis, has been implicated. Chytridiomycosis in the U.S.A. is mainly caused by the Batrachochytrium dendrobatidis. In this study, I used qPCR assays to detect the existence of this pathogen in the Eastern Hellbender (Cryptobranchus alleganiensis alleganiensis) populations in the Allegheny and Susquehanna River drainages of New York and Pennsylvania. Chytrid is most often tested by using skin swabs, but in this study, tail clips, dorsal skin, blood and eggs were tested as well. Batrachochytrium dendrobatidis was detected in tail clips in this study, although the tail clip samples seemed to have lower Bd detection sensitivities and concentrations compared with swab samples. Only three out of 41 samples that had tested positive for swabs also tested positive for tail clips, and very small tail clip samples did not result in chytrid positives, despite a relatively high known rate of infection in Pennsylvania. Batrachochytrium dendrobatidis was detected in 8.5% of NY and 2.4% of PA tail clip samples (out of 124 total) and from tail clips taken as early as 2004 in the NY Allegheny River drainage. This shows that archival samples, often available for genetic testing, may also be used for Bd detection. The Bd positive rate from swab samples (25 in total) was 56.0% in NY