STABLE ISOTOPE ANALYSIS OF THE FOOD WEB ECOLOGY OF ENDEMIC FRESHWATER MUSSELS (UNIONIDAE) IN CENTRAL TEXAS
Unionid mussel populations are declining as a result of various anthropogenic stressors. The increased awareness of their ecological function and their imperiled status has driven greater concern for mussel conservation. Although it is widely assumed that mussels are filter-feeders, much remains unknown regarding their food and feeding relationships. Understanding their feeding ecology is necessary to further understand their role in ecosystem processes, the causes of their decline and to aid in propagation and relocation programs. In this study, we use stable isotope analysis (13C, 15N) to assess multiple food resource categories including fine particulate organic matter associated with benthic sediments (FPOM), suspended particulate organic matter (SPOM), aquatic plants, and coarse detrital organic matter (CPOM). We collected seasonal tissue samples from three endemic Texas species (Cyclonais petrina, Cyclonais houstonensis and Lampsilis bracteata), and potential food source samples from the site of mussel collections across four basins. Mussel 13C and 15N values suggested that all three mussel species were feeding similarly. The majority of the carbon assimilated appeared to be derived from detrital CPOM, while SPOM and FPOM played relatively minor roles in the contribution to dietary carbon.
Kaelyn Fogelman (Primary Presenter/Author), Auburn University , firstname.lastname@example.org;