Genetic Variation within and among Species of Freshwater Mussel, Elliptio complanata, in the Delaware, Raritan, and Susquehanna Watersheds

Jaclyn Kahn,  Biology

Faculty Mentor: Dr. Curt Elderkin

              The preservation of genetic variability is imperative to the long-term survival of freshwater mussel populations.  The absence of genetic variation has been linked to extinction and limits a population’s ability to adapt in the face of changing environments. Worldwide, freshwater mussel families Margaritiferidae and Unionidae, diverse components of North America’s freshwater ecosystems, are imperiled.  In North America, 70% of mussel taxa are either endangered, threatened, or of special concern.  Genetic variability is pertinent to analyze because the absence of genetic variability would suggest that habitats in the Susquehanna River and its tributaries are vulnerable to a loss of biodiversity.  Collecting and analyzing genetic data from E. complanata could lead to an informed conservation recommendation for the habitats. Currently we have collected genetic data from 32 individuals and from three watersheds (Susquehanna, Delaware, and Raritan). Sixteen DNA samples were randomly selected from the thirty individuals found at each of the sampled sites.  The cytochrome oxidase subunit one (CO1) mitochondrial gene (~600 base pairs) was amplified due to its proclivity to genetic variability within populations.  Subsequent to PCR amplification, individuals were sequenced using CEQ-800 (Beckman Coulter Inc.) protocols. The objectives of my current project were: 1) to locate and document existing populations of E. complanata and all other mussel species populations found in the area of the Susquehanna Watershed; 2) to take a 100mg sample of mantle tissue extracted from 30 individuals at each site for further genetic study; 3) to randomly select 16 individuals from each of the sites to be analyzed and compared to the genetic data on E. complanata populations of the Delaware and Raritan Watersheds.  These objectives will enrich our understanding of the biodiversity of freshwater mussel populations in the in the Northeastern United States and will provide genetic support to generate possible conservation decisions for the Susquehanna, Delaware, and Raritan Watersheds.

Personal Statement

              The SURP program here at TCNJ has expanded my horizons in the field of scientific research.  The program not only allowed me to interact with my fellow researchers, but it also supplied me with fun activities and forums for academic discussion. Wednesday breakfasts were a great opportunity to discuss research goals and get to know the other biology researchers.  Field research was also introduced to me this summer, providing me with a deeper understanding of my research and adding a prospective to my research goals.  I hope that this firsthand look at the rivers we sampled will help me better understand my research results.  Troubleshooting was one of the most important skills I learned this summer in both field work and lab work.  In both aspects we encountered difficulties, yet we were able to work together to get around them by employing new techniques or simply trying another sampling site.  Overall, I loved being here this summer and would love to be a part of the program again in the future.