Meeting Abstract
Batoids (rays and skates) fulfill an important ecological niche as mesopredators in marine ecosystems, transferring energy from lower trophic levels and making it available to apex predators. Lipids (fatty acids and sterols) are one mechanism whereby energy is stored and transferred through trophic levels. Lipid metabolites are transported in blood plasma to tissues based on necessity, therefore blood lipid concentrations provide a snapshot of the energy usage in an animal at a given point in time. Triglycerides (TAG) are one type of lipid stored in the liver, which under oxidation to provide energy for other tissues. However, the means by which rays recruit and utilize TAG is not well-understood. The purpose of this study was to establish baseline concentrations of TAG in three wild-caught ray species. Blood samples were collected from Gymnura micrura (smooth butterfly ray; n=12), Hypanus say (bluntnose stingray; n=9), and Hypanus sabinus (Atlantic stingray; n=15) from commercial trawls. Plasma concentrations of TAG were quantified using a colorimetric assay. Gymnura micrura had a significantly greater (p<0.05) plasma TAG concentration (1.724 mmol/L± 0.573 SEM) than H. say (0.948 mmol/L ± 0.206 SEM) and H. sabinus (0.755 mmol/L ± 0.134 SEM). Results from this study can provide a basis for future research to investigate the influence of specific ecological factors, such as activity level, ontogeny, and seasonality, on lipid metabolite concentrations.
