Effects of Nutritional Condition on The Immune Defense Capabilities of Northeastern Salamanders

Authors: Eric Jergensen, Cynthia Downs

SUNY Campus: SUNY ESF

Presentation Type: Poster

Location: Old Union Hall

Presentation #: 35

Timeslot: Session A 9:00-10:00 AM

Abstract: Batrachochytrium dendrobatidis, a prevalent amphibian disease-causing agent, primarily attacks host cutaneous tissues and is implicit in the decline and extinction of frog and salamander species. Antimicrobial peptides (AMPs) are an amphibian’s first line of immune defense against pathogenic organisms and can decrease mortality rates of Bd hosts, however, the effectiveness of AMPs from salamanders to inhibit Bd growth is largely unstudied. Ecoimmunology theory predicts that body condition will mediate investment in immune defenses, such that animals in poorer nutritional condition will have less constitutive immune defenses. The role of nutritional constraints on the immune system of amphibians, however, is little studied. To address these questions, we collected AMPs from Eurycea bislineata salamanders found in temperate forests within central New York State and will use them in comparative fungal inhibition assays against Bd at numerous concentrations. We will use a linear model to quantify a relationship between fungal inhibition and salamander condition (measured as residuals of each individual’s length and mass). If our hypothesis is correct, we expect greater concentrations of AMPs to exhibit greater levels of fungal inhibition. We also expect a positive association between nutritional condition and Bd inhibition. These results would be consistent with nutritional investment strategies observed in other animal groups and support additional concerns regarding amphibian resistance to Bd in natural systems.