VARIATION IN EGG QUALITY IN BLUE CRABS, CALLINECTES SAPIDUS, FROM NORTH CAROLINA: DOES FEMALE SIZE MATTER?

Understanding the reproductive biology of commercially important species is important to ensure the continued health and sustainability of marine ecosystems. North Carolina's blue crab fishery is the fifth largest crab fishery in the United States, and the current stock status is "of concern" due to recent low harvest totals. Thus, knowledge of factors contributing to future recruitment in this fishery is clearly needed. There are few data on the variation and consequences of blue crab female size on egg quality; this study aimed to evaluate whether female size has any bearing on egg quality or larval size. Eggs of 110 ovigerous females were sampled in June through July of 2010 and 2011, and the eggs' energy content, lipid content, and fatty acid profiles were measured. Eighteen ovigerous females were maintained until hatch, at which point zoea sizes were measured. Female size did not strongly correlate with any measurement of egg quality or zoea size. Energy content and fatty acid profiles significantly differed between 2010 and 2011. Eggs extruded later in the season had higher dry weight energy content in 2011, while overall zoea size declined in later hatch dates. Our results indicate that lipid content in blue crab eggs does not drive overall energy content, and female size does not correlate with our measures of reproductive success. Instead, we propose that environmental or genetic factors are responsible for this variation. Management plans for protecting blue crab broodstock should reflect annual variation present in egg quality rather than emphasizing the influence of female size on egg quality.