Showcase of Undergraduate Research and Creative Endeavors (SOURCE)

Gut Content Analysis of Aquatic Macroinvertebrates using DNA-Based Methods

Richardson Ballroom – DiGiorgio Campus Center

With the great deal of complexity associated with aquatic food webs, many questions regarding species interactions remain unanswered. One such question of importance is: Who is eating whom? This is a question that morphologically based analysis techniques have failed to answer with great accuracy. However, with the advent of DNA-based analysis methods, this question can be answered. DNA-based analysis methods allow for greater certainty in taxonomic identification, because specific gene regions can be targeted using group-specific primers as a means for DNA detection. This approach was used to analyze dragonfly (Odonata, Anisoptera) gut contents using group-specific primers for midges (Chironomidae) and mosquitoes (Culicidae) as potential prey groups. Specimens were collected in Big Dutchman Creek and Winthrop Lake in Rock Hill, South Carolina. DNA was extracted from gut contents of collected specimens. A polymerase chain reaction was performed on each of the extracted samples in order to amplify DNA concentrations. Gel electrophoresis was used as a presence-absence test for DNA from target prey groups. We found that one individual of the genus Progomphus contained DNA from the family Chironomidae, but not Culicidae. A second Progomphus individual tested negative for both families, illustrating individual variation in feeding. These refined methods will allow for testing of more Progomphus individuals and potential prey groups as well as other aquatic macroinvertebrate predators.