Meeting Abstract

P1-111  Thursday, Jan. 5 15:30 – 17:30  Using Next Generation Sequencing to Identify Local Adaptation to Salinity in the American Oyster, Crassostrea virginica, on the Louisiana Gulf Coast RILEY, SM*; KELLY, MW; LA PEYRE, MK; LA PEYRE, JF; Louisiana State University; Louisiana State University; Louisiana State University; Louisiana State University srile14@lsu.edu

Salinity plays a key role in the distribution of American oysters, Crassostrea virginica, an estuarine species that provides food, shelter, and nursery habitat for numerous species in the Louisiana Gulf Coast. Climate change affects salinity by altering precipitation patterns which in turn alter the frequency, location, and volume of freshwater inflow to estuaries.  To improve accuracy of predicted responses of C. virginica to climate change, we want to test if oyster populations are locally adapted to salinity. We will use Restriction Site Associated DNA Sequencing (RADseq), to identify potential SNPs responsible for differences in salinity tolerance between two populations of oysters: Vermilion Bay (average salinity 5.6ppt) and Lake Fortuna (average salinity 14.9ppt). To test for differences in the phenotypic response to salinity, we will conduct a reciprocal transplant experiment with oysters spawned from high, medium, and low salinity sites, and measure growth and survival over a one year period.  Additionally, we will determine the salinity tolerance by calculating LD₅₀ at 6, 12, 18, and 24 ppt salinity with oyster larvae from each parental population. From the RAD sequencing data, we expect to identify SNP’s responsible for variation in salinity tolerance across populations. We expect larvae will have lower mortality at their native salinity and that growth will be highest and mortality lowest at outplant sites with similar salinity to the parental stock. Identifying markers associated with salinity tolerance will assist in the selection of breeding stocks for use in restoration or aquaculture.