Spawning biology of the blue crab, Callinectes sapidus, in North Carolina

The blue crab, Callinectes sapidus Rathbun, supports valuable fisheries in many Atlantic and Gulf Coast states. We studied the spawning biology of female crabs hand-captured in the Carrot Island Embayment, central North Carolina. Crabs were retained sub-tidally in submerged, partially buried minnow traps and fed daily. Of 124 experimental animals, 66% had two or more clutches of eggs with three individuals producing seven clutches over 18 wks. The longer the crabs were held, the more clutches they produced. We infer that an average size crab (127 mm carapace width) would produce eight clutches over a 25-wk spawning period. Since larger crabs had larger clutches but produced them less frequently than smaller crabs, reproductive output over 18 wks of the spawning season was statistically similar for most size groups. Lipofuscin index values were higher for crabs that had recently molted to maturity than for crabs that had been spawning for 18 wks. Sponge damage of 2307 crabs, determined by the degree of deviation from the rounded form of an intact sponge, indicated that animals caught by crab-pots had significantly more sponge damage than hand-captured crabs. Sponge damage was most extensive during mid-summer and the extent of damage differed among the smallest and largest size groups during this time. Our finding that reproductive output is similar for most size groups brings into question management plans that suggest the release of the largest mature females. © 2006 Rosenstiel School of Marine and Atmospheric Science of the University of Miami.

Duke Scholars

Author Daniel Rittschof Marine Science and Conservation