The activity and feeding behavior of ovigerous Dungeness crabs, Cancer magister, were examined as part of a long-term study. Part of this study surveyed Bartlett Cove in Glacier Bay, Alaska, during the spring of 1994 where 50 commercial pots were soaked for 24 hours. Catch per unit effort (CPUE), dispersion, and stomach samples of male, nonovigerous female, and ovigerous female crabs were compared. A laboratory experiment compared feeding rate, foraging response, and survival between starved and fed ovigerous and nonovigerous crabs over a six-month winter period (December 1994-May 1995).
CPUE differed significantly for crabs of different reproductive groups caught in pots during the spring 1994 survey in Bartlett Cove (ANOVA, P< 0.01). CPUE averaged 3.7 ± 0.5 (standard error) for males, 1.3 ± 0.3 for nonovigerous females, and 0.4 ± 0.1 for ovigerous females. Male and nonovigerous female Dungeness crabs were homogeneously dispersed throughout the pot transect area; however, ovigerous crabs were aggregated. A significant difference in dry weight of stomach contents and stomach fullness between reproductive groups existed.
Ovigerous females had significantly lower feeding rates than nonovigerous females in the laboratory (two way ANOVA, P< 0.01). The foraging responses of ovigerous crabs were significantly lower in comparison to nonovigerous females (Mann-Whitney U test, P< 0.01). Seasonal differences were also found for foraging within the two groups over the course of the study period (Kruskal-Wallis one-way ANOVA, P< O.OI). No mortality occurred in treatments of fed and starved ovigerous and nonovigerous crabs over the six-month experiment, demonstrating Dungeness crabs can survive overwinter without feeding in laboratory conditions.
