OUP accepted manuscript

Abstract

Abstract Fisheries management requires a thorough understanding of the processes involved in reproduction, including the ability to distinguish sexually mature individuals. The Jonah crab, Cancer borealisStimpson, 1859, occurs from Newfoundland to Florida, but the fishery is concentrated in New England. The crab contributes to a significant and growing male-driven fishery; however, little is known about its life history. We investigated the relationship between morphometrics and physiological maturity, and the size at which these life changes occur in the southern New England stock. The size at 50% sexual maturity (SM50) in male C. borealis was estimated morphometrically to be 105.9 mm carapace width (CW). This size is larger than the estimate of 98.3 mm CW for the species in the Mid-Atlantic Bight but lower than the estimate of 127.6 on the Scotian Shelf, consistent with a poleward gradient in size at maturity. The gonadosomatic index differs significantly between CW size groups, maturity status, and season whereas spermatophore size was not related to CW. Fisheries management should include multiple measures of sexual maturity and consider factors including geographical distribution when establishing and assessing guidelines for this economically important species.