This article comes from “Tide Bites”, the monthly newsletter of UW Friday Harbor Laboratories. “Red rock crabs: the Dungeness’ grouchy cousins” by Sylvia Yamada and Scott Groth: read the full article at the FHL website.
Native red rock crabs (Cancer productus) are important predators on protected rocky nearshore communities from Alaska to Baja California. While they are harvested recreationally, they have not been as well studied as their commercially-valuable cousin, the Dungeness crab. Red rock crabs are abundant on semi-protected rock and boulder beaches where the substrate is composed of sand and shell gravel and where the salinity remains high. They have voracious appetites, feeding on a wide variety of species including barnacles, mussels, clams, oysters, snails, worms and sea cucumbers. Adults are highly mobile and are known to move into the high intertidal during flood tides to forage. We decided to piece together the life cycle of the red rock crab by compiling what was learned through various studies carried out on different life stages at Friday Harbor Laboratories.