Honors Theses
Date of Award
Fall 11-8-2023
Document Type
Undergraduate Thesis
Department
Biology
First Advisor
Deborah Gochfeld
Second Advisor
Kristine Willett
Third Advisor
Tamar Goulet
Relational Format
Thesis
Abstract
The U.S. Gulf of Mexico contains the largest remaining wild oyster fishery in the world, but populations have declined in recent decades. A growing interest in off-bottom aquaculture that relies on triploid eastern oysters (Crassostrea virginica) has emerged in the Gulf region, yet these faster growing oysters suffer high mortality as adults during low salinity events (< 5 ppt) in warmer summer months. The combined effects of salinity and temperature stressors on early life stages of triploid oysters are unknown. Early life stages are particularly crucial to understand because triploid oysters do not occur naturally and must be reared in hatchery settings, requiring appropriate water conditions to yield the greatest survival and growth. Thus, we tested the effects of different temperatures (28oC and 32oC) and salinities (5, 10, and 15 ppt) on diploid and triploid oysters at three critical production stages: veliger, pediveliger, and spat. Veliger survival was significantly lower for triploids relative to diploid oysters at all experimental conditions, but triploid veligers had faster growth than diploids at 32oC and 15 ppt. Pediveliger settlement was not affected by ploidy type and only reduced at high temperature (32oC) and the lowest salinity (5 ppt). Diploid spat showed highest survival at 28oC and 15 ppt, while triploids survived best at 32oC and 15 ppt. Triploid spat attained greater shell height compared to diploids in our 6-day exposures, but growth decreased for both ploidies at lower salinities. At the salinity and temperature levels examined, diploid early life stages performed best at 28oC and 15 ppt, whereas triploids were more successful at 32oC and 15 ppt. A broader understanding of the combined effects of environmental stressors will improve the success of hatchery production yields and the resulting economic and environmental benefits of the oyster industry.
Recommended Citation
Boudreaux, Christian; Pruett, Jessica; Carpenter, Alexz; Willett, Kristie; and Gochfeld, Deborah, "Effect of Ploidy on Salinity and Temperature Tolerance in Early Life Stages of the Eastern Oyster (Crassostrea virginica)" (2023). Honors Theses. 3190.
https://egrove.olemiss.edu/hon_thesis/3190
Included in
Aquaculture and Fisheries Commons, Biology Commons, Genetics Commons
