Assessing Effects of Translocation on Amphibian Chytrid Fungus and the Cutaneous Bacterial Assemblage of Wild Eastern Hellbenders (Cryptobranchus alleganiensis alleganiensis)
Eastern Hellbenders (Cryptobranchus alleganiensis alleganiensis) are large, fully aquatic salamanders experiencing precipitous population declines across their range and as such have been proposed as candidates for translocations. Success of these projects is dependent on multiple factors but may be unsuccessful if individuals succumb to disease or experience negative health effects and are unable to adjust to a new environment. The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) has caused massive die-offs of amphibian populations worldwide and has been associated with hellbender mortality in translocations. Additionally, the cutaneous bacterial microbiome of amphibians plays a role in host health by inhibiting infection by pathogens and has been shown to be affected by a change in environment, such as a translocation. Monitoring disease prevalence and characterizing the skin-associated microbiota of amphibians should be an essential component of translocations to evaluate host health. However, no studies have evaluated how these health parameters are affected by translocation in this species using intra-individual data from one year pre- and post-translocation. We conducted a translocation of wild adult Eastern Hellbenders in East Tennessee to augment declining populations in this region. We tested Bd prevalence using qPCR and characterized the cutaneous bacterial assemblage of hellbenders using next generation sequencing pre- and post-translocation. Hellbenders had a pre-translocation Bd prevalence of 50% (15/30), and Bd prevalence decreased post-translocation to 0%. No hellbenders showed any sign of chytridiomycosis for the duration of the study. We found 1700 OTUs associated with the hellbender skin bacterial assemblage and these communities were composed primarily of members of Proteobacteria and Bacteroidetes. Hellbenders shared 56% of skin bacteria with the environment but were structurally different. Lastly, we found that translocation had a significant effect on the bacterial community structure of hellbenders. Although we noted changes in relative abundances of these communities, no hellbenders exhibited health deteriorations. We showed that wild adult hellbenders can be successfully used in translocations without increased disease prevalence or health declines associated with the skin bacterial assemblage.
"Assessing Effects of Translocation on Amphibian Chytrid Fungus and the Cutaneous Bacterial Assemblage of Wild Eastern Hellbenders (Cryptobranchus alleganiensis alleganiensis)"
ETD Collection for Tennessee State University.