The eastern hellbender (Cryptobranchus alleganiensis alleganiensis) is a North American salamander species in decline throughout its range.7,8 Efforts to identify the causes of decline have included surveillance for the chytrid fungus Batrachochytrium dendrobatidis (Bd), which has been associated with global amphibian population losses.2,5 Several studies have evaluated prevalence of Bd in various hellbender populations in New York, Pennsylvania, Virginia, Ohio, Indiana, Missouri, and Tennessee.1,3,4,6
Wild hellbenders have not been reported to display clinical disease associated with Bd; however, prevalence in the population is important information for evaluating reservoir status, risk to other species, and as a baseline for investigation in the face of an outbreak of clinical disease.
The importance of surveillance and ongoing research into the behavior of chytrid fungus in these populations is highlighted by the recent emergence of a second species of the fungus, Batrachochytrium salamandrivorans. Although it has not been detected in initial surveys of eastern hellbenders, it appears to have increased pathogenicity in salamander species and is another pathogen of concern when considering amphibian conservation.1 Since many zoological facilities are active participants in ongoing hellbender conservation and reintroduction efforts, the aim of this presentation is to provide clinicians with the most up-to-date information regarding chytrid in the species.
1. Bales EK, Hyman OJ, Loudon AH, et al. Pathogenic chytrid fungus Batrachochytrium dendrobatidis, but not B. salamandrivorans, detected on eastern hellbenders. PLoS ONE. 2015;10(2):e0116405. doi:10.1371/journal.pone.0116405.
2. Berger L, Speare R, Daszak P, et al. Chytridiomycosis causes amphibian mortality associated with population declines in the rain forests of Australia and Central America. Proc Natl Acad Sci. 1998;95:9031–9036.
3. Bodinoff CM, Briggler JT, Duncan MC, Beringer J, Millspaugh JJ. Historic occurrence of the amphibian chytrid fungus Batrachochytrium dendrobatidis in hellbender Cryptobranchus alleganiensis populations from Missouri. Dis Aquat Org. 2011;96:1–7.
4. Burgmeier NG, Unger SD, Meyer JL, Sutton TM, Williams RN. Health and habitat assessment for the eastern hellbender (Cryptobranchus alleganiensis alleganiensis) in Indiana, USA. J Wildl Dis. 2011;47:836–848.
5. Lips KR, Brem F, Brenes R, et al. Emerging infectious disease and the loss of biodiversity in a neotropical amphibian community. Proc Natl Acad Sci. 2006;103:3165–3170.
6. Souza MJ, Gray MJ, Colclough P, Miller DL. Prevalence of infection by Batrachochytrium dendrobatidis and Ranavirus in eastern hellbenders (Cryptobranchus alleganiensis alleganiensis) in eastern Tennessee. J Wildl Dis. 2012;48:560–566.
7. West Virginia Division of Natural Resources. Rare, threatened and endangered animals: West Virginia Natural Heritage Program, http://www.wvdnr.gov/Wildlife/PDFFiles/RTE Animals_ 2012.pdf. 2012. Accessed October 2014. (VIN editor: Link was not accessible as of 12-1-20.)
8. Wheeler BA, Prosen E, Mathis A, Wilkinson RF. Population declines of a long-lived salamander: a 20+-year study of hellbenders, Cryptobranchus alleganiensis. Biol Conserv. 2003;109:151–156.