Biology/Natural History: This species is onmivorous, and feeds on algae, small mollusks, and barnacles. Sometimes captured individuals extend and lock their claws when handled. Eggs are carried beginning in March and hatch from May to August in British Columbia. Many females produce 2 broods per year, with 6,000 to 36,000 eggs per brood. May be parisitized by the Rhizocephalan Sacculinid barnacle Loxothylacus panopaei (picture) (At Sitka, Alaska perhaps 25% of the crabs are parasitized). I have not found this high a percent parasitism in the Puget Sound area. Fossils of this species have been found in Pleistocene deposits in Playa del Rey, southern California. This species has 124 chromosomes (62 pairs).