By Morgan Hicok

Faculty Mentor: Abbie Tomba

Abstract

Flatworms are internal parasites with complex, multi-host lifecycles. Most infect freshwater snails as their first intermediate host. The presence of flatworms allows us to draw conclusions about stream health and functioning, and serves as an ecological indicator. This study addresses water level and flow in relation to diversity of parasitic infection in freshwater snails in the Fredericksburg, VA region. The effect that water level has on parasitism has not been closely studied in the Rappahannock River. Additionally, other studies have failed to address diversity of infection. Here, I examine trematode prevalence; looking specifically at water levels and flow. Snails were collected during the fall of 2023. Collection will continue through the summer and fall of 2024. Square foot quadrats will be randomly selected for sampling. Snails will be hand picked and habitat measurements will be taken at each sample location. Parasites found in the snail tissue will be identified and categorized using PCR and gel electrophoresis. Thus far, a few flatworms have been run through this process. 2023 proved to have low water levels, possibly affecting the overall rate of parasitism. I hypothesize there to be an increase in trematode diversity as a result of decreased water levels and flow. This is because it may be easier for flatworms to find hosts due to a decrease in aquatic habitat.