Carson Lillard

Academic Year: 2014-2015
Name: Dr. Matthew Gray
Department: Forestry, Wildlife and Fisheries (Center for Wildlife Health)
UTIA Appointment: Ag Research / CASNR
Student: Carson Lillard
Student Department: Forestry, Wildlife and Fisheries (Center for Wildlife Health)
Title of Student Project: Susceptibility of Eastern Hellbenders to Pathogens and Pesticides
Publications: N/A
Presentations: Exhibition of Undergraduate Research and Creative Achievement (EUReCA), Knoxville, TN; Third International Symposium on Ranaviruses, Gainesville, FL.; Seventh Hellbender Symposium, St. Louis, MO.
Other Products: N/A
Abstract of Student Project (when Completed): 

The eastern hellbender (Cryptobranchus alleganiensis alleganiensis) of North America is declining in several watersheds, and pathogens may be playing a role. Ranavirus is a global emerging pathogen that is known to infect hellbenders; however, reports of morbidity due to this disease agent are rare.  My goal was to test the susceptibility of eastern hellbender larvae to ranavirus at two water temperatures (15 and 22 C) typical in the wild.  Hellbenders were exposed to ranavirus in water at an environmental relevant concentration for three days, and their survival monitored for up to 33 days. No signs of disease or mortality were observed at 15 C.  Signs of ranaviral disease (i.e., cutaneous lesions, hemorrhage) were observed after 14 days post exposure at 22 C.  By the end of the experiment, only 1/3 of the exposed hellbender larvae survived.  High viral loads and extensive necrosis were documented in the liver and kidney.  Our results indicate that eastern hellbender larvae are susceptible to ranavirus, with pathogenicity greater at warmer water temperatures. Anthropogenic land uses that cause increases in water temperature (e.g., tree removal near streams) and atmospheric warming associated with climate change might contribute to ranavirus emergence in hellbender populations.  Future experiments include testing the toxicity of the most common agricultural herbicide in the USA (glyphosate) to hellbenders, testing the susceptibility of hellbenders to another emerging pathogen (Batrachochytrium dendrobatidis), and determining if sub-lethal concentrations of glyphosate increase the susceptibility of hellbenders to pathogens.​


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Student: Carson Lillard

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Mentor: Dr. Matthew Gray