Search
Cancer productus
Adult
Juvenile
Common Name: The Red Rock Crab
Size:
Males to 20 cm and females to 15.8 cm.
Range:
From Kodiak, Alaska to San Diego, California. Plentiful in Puget Sound.
Misidentification:
May possibly be confused with Cancer gracilis and Cancer magister. Cancer productus is identified by distinct black tipped chelipeds and a carapace which is widest at the 8th and 9th postorbital spines.
Habitat:
Found in areas with rocky outcrops that contain gravel bottoms often with kelp beds. Cancer productus is usually found in areas that are somewhat sheltered such as bays and estuaries. May be found to a depth of 90 meters.
Life History:
Mating generally occurs from May through August. Fertilized eggs hatch during March and April. The planktonic larval phase consists of five zoel stages and one megalopa stage, larval phase duration is 3 - 4 months. Adults are voracious predators and prey on mollusks such as clams and mussels and are predatory toward other crabs as well. Aquaculture operations that engage in the farming of clams may be severely affected by Cancer productus if preventative measures such as the laying of predator exclusion netting is not utilized.
Natural history:
Cancer productus may host parasitic nemertean worms. These worms belong to the genus Carcinonemertes and are found under the legs of the crab at the coxopodite. These parasitic worms may also be found among the eggs that a female crab may be carrying. The worms will appear as small reddish spots.
Predators:
The Pacific giant octopus, Enteroctopus dofleini, many marine fishes when the crab is in the juvenile stage, and humans (there exists a large recreational fishery in the State of Washington).
Additional Resources:
Pacific Coast Crabs and Shrimps 1995. Gregory C. Jensen. Published by Sea Challengers, Monterey, California.
Last updated Thursday, August 24, 2006, by Lisa Ferrier
