Dungeness crab Cancer magister, the most important commercial crab of the Pacific north-west coast of the USA. Carapace width may be as much as 20 cm (8"). The back is reddish-brown or purplish in life, turning to red or orange when the crab is cooked. This crab and C. pagurus (see crab, common) are closely related and match each other in quality.
Ricketts and Calvin (1978) remark in connection with this species:
The exoskeleton of a crab presents a formidable barrier to love-making; and although it seems to be the general rule that mating of crabs requiring internal fertilization can take place only when the female is still soft from molting, the process has not often been observed.