WELLS, S.L.*; MCCONAUGHA, J.R.; Old Dominion University; Old Dominion University: Fecundity and Reproductive Energetics in the Chesapeake Bay Blue Crab, Callinectes sapidus

The blue crab, Callinectes sapidus, has historically been a major fishery in the Chesapeake Bay. Both fishery dependent and independent data indicate that the population declined abruptly in the mid-1990�s and has remained low, which has raised concerns about the health of the Bay population. Fishery independent observations also indicate that the mean carapace width of mature female crabs in the Bay has declined. Previous reports found a significant relationship between size and fecundity for mature females in this population. This was similar to allometric relationships reported for other brachyuran crustaceans. Fecundity estimates for the spawning stocks of 2002-2005 indicate that individual female fecundity was an order of magnitude lower than previously reported. This suggests that the allometric size/fecundity relationship is no longer valid for this population. The production of fewer eggs per mature female, along with a decline in spawning stock size, suggest a major change in population fecundity. Alternative non-allometric regulation has been examined. The current gonadal index was similar to data from the early 1980�s. This indicates that each individual is still producing a consistent amount of ovarian tissue. Lack of sufficient energy resources to produce the maximum number of eggs would be a strong alternative control factor. One likely extrinsic source for the fecundity changes is reduced prey availability, which has been documented throughout the Bay. The allocation of resources was examined by determining the lipid and protein concentrations of the hepatopancreas, ovaries, and eggs of mature females. Quantitative differences in lipid types in these tissues were also examined.