Striped bass fatty acid signature incorporation: The effect of size

The study of trophic interactions in the Chesapeake Bay has often relied on traditional gut contents analysis. These results offer a snapshot of feeding history and are skewed towards the last meal eaten. Fatty acids are a group of macromolecules that are transferred from prey to predator with little modification. This allows the diet of fish to be tracked over a period of weeks rather than days. To evaluate the influence of fish size on prey signature incorporation, 16 striped bass (Morone saxatilis) in each of 3 size groups, 15-20 cm, 30-38 cm, and greater than 46 cm, were maintained in a flow through system at ambient Choptank River, MD temperature and salinity.  Fish were fed a diet of spot (Leiostomus xanthurus) for 4 weeks to create a baseline signature, and then fed a diet of Atlantic menhaden (Brevoortia tyrannus) for the duration of the 6 week experiment. Striped bass were serially collected on day 0, 14, and 28. Results will be presented comparing the fatty acid signatures of striped bass to menhaden to determine the influence of fish size on the incorporatation  of prey signature.