Development of a Molecular Genetic Method for Characterizing Amphibian Diets

DEVELOPMENT OF A MOLECULAR GENETIC METHOD FOR CHARACTERIZING AMPHIBIAN DIETS.Alexander Funk* and Todd W. Pierson, Department of Ecology and Evolutionary Biology, University of Tennessee Knoxville, afunk4@vols.utk.edu

Dietary studies can provide key insights into the ecology and behavior of animals. Methods common in dietary studies of amphibians (e.g., gastric lavage, fecal analysis, dissection) often fail to identify prey beyond the level of Order, are time intensive, and can be biased against soft-bodied prey. Here, we are developing a DNA metabarcoding assay to characterize amphibian diets from non-invasive fecal samples. In DNA metabarcoding, barcoding loci from mixed community samples (e.g., feces) are sequenced on a next-generation sequencing platform, and resulting reads are used to identify members of that community (e.g., diet composition). To validate this method, we will prepare COI amplicon libraries from 27 fecal samples collected from wild Blue Ridge two-lined salamander (Eurycea wilderae) during the breeding season. We will sequence these reads on an Illumina MiSeq and compare resulting reads against a reference library of sequences of known identity to characterize invertebrate diet composition. Some of our samples are derived from male E. wilderae with two alternative reproductive tactics-“searching” and “guarding”. Because the latter is more likely to be found in aquatic habitats in the breeding season, we expect to find a great representation of aquatic invertebrates in its diet. We hope that this method will prove to be more accurate and efficient than previous methods, providing a new, versatile tool with which amphibian diets can be characterized and compared.