Impacts of Salinity and Seasonality on Reproductive Physiology in Diploid and Tetraploid Eastern Oyster (Crassostrea virginica)

Abstract

The demand for high-value aquaculture products, like Eastern oyster (Crassostrea virginica), necessitates efficient commercial hatchery strategies. Triploid oysters, derived from mating diploid females with tetraploid males, exhibit enhanced growth and meat quality. However, challenges in triploid production persist due to various factors, particularly low gamete quality. This thesis investigated the influence of salinity on gamete quality in Eastern oyster and provided a comprehensive assessment of male tetraploid and female diploid gametogenesis and gamete quality over the annual cycle. Lower salinities negatively impacted most sperm traits while higher salinity increased lipid peroxidation and egg irregularities. Gamete quantity and quality varied annually with all sperm traits displaying peak performance in June and July. High-quality oocytes were also produced in June and July. These findings emphasize the importance of salinity and season in gamete quality and offer novel insights for optimizing the aquaculture of Eastern oyster in the Gulf of Mexico.