Maturity, Mating, and Egg Laying in the Spider Crab, Chionoecetes opilio

• Published in: Journal of the Fisheries Research Board of Canada
• Main Author: Watson, J.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1970
• Subjects: Vasa; Chionoecetes opilio
• Online Access: http://dx.doi.org/10.1139/f70-181; http://www.nrcresearchpress.com/doi/pdf/10.1139/f70-181

Morphometric measurements and gonad examination of the spider crab, Chionoecetes opilio, showed that 50% maturity occurred at about 57 and 50 mm carapace width for males and females, with minimum sizes at maturity of 51 (males) and 47 mm (females). Both sexes were mature at sizes considerably below the commercially acceptable size of 4 inches (102 mm) carapace width. After maturity, positive allometric growth was demonstrated for males. Females do not moult after reaching maturity. The small vasa deferentia found in soft-shelled mature males suggested that only hard-shelled males were capable of mating. A hard-shelled male successfully mated with a soft-shelled mature female. Field and laboratory observations suggest that more than one brood is commonly produced from one mating.The minimum size limit for commercial landings allows some mature males capable of mating to be left on the fishing grounds. Retention of this limit seems unlikely to affect the breeding potential of the population.