The Dungeness crab is an important commercial and sports fishing species in Oregon. The fishery is regulated by sex, size, and season. This study examined whether female crabs are mating despite the removal of almost all legal-size male crabs each year. Of particular concern is whether large females are finding large enough mates. Females were collected from three Oregon fishing ports, dissected, and checked for evidence of mating. Captured male and female crabs were also measured to estimate population size distributions. The majority of female crabs examined (69%) mated in the collection year, and when combined with crabs that carried sperm from previous mating encounters (females store sperm), the percent of females that would have produced viable eggs was 83%. Crabs that definitely molted during the collection year showed higher mating success (95%). The largest females examined (carapace width, 160-169 mm) showed high mating success (84% Mated in the collection year, 95% could have produced viable eggs). These numbers compare favorably with a similar survey conducted in northern California, in which 69% of molting females had mated. We conclude from the data that molting females in these Oregon fishing ports are finding mates successfully, regardless of size.
Journal of Shellfish Research, 2012, Vol 31, Issue 3, p. 835-839
Dungeness crab; Cancer magister; mating; Oregon; fertilization; fishery