Have a thick, round, ribbed shell with many spines.
Shells often covered in plant, animal, and algae growth.
Mantle (scallop body seen at edge of shell) is bright orange with black eyes and sensory tentacles running along it.
Up to 10 inches in diameter as adults.
Juvenile rock scallops are unattached to a substrate and swim by clapping their valves together and squirting water out the sides of the hinge.
Permanently attached to hard substrate as adults; they settle and cement themselves at about 1 inch in diameter.
From northern Alaska to northern Mexico.
Live in intertidal (area of shoreline covered at high tide and uncovered at low tide) and subtidal (below the low-tide line) waters along exposed outer coasts.
Found under rocks and in crevices.
Found at depths of 0-252 feet.
Reproduce by broadcast spawning, releasing sperm and eggs into the water.
Spawn twice a year in Southern California, once in late spring-early summer, and again in mid-fall.
Rock scallops are suspension feeders who filter particulates and plankton out of the water.
Lobsters, crabs, sea stars, fishes.
Traditional food of coastal First Nations people.
Rock scallops are the heaviest and the second-largest scallop species.
They are sometimes called the purple-hinged rock scallop because the interior of their hinges are purple.
Unlike all other scallops, rock scallops cement themselves down permanently to a hard surface once they reach maturity (about an inch across).
These scallops can live for up to 20 years.
Sources: CentralCoastBiodiversity.org; Macdonald et al. 1991; lobsteranywhere.com, UMass; Catalina Island Marine Institute; Oregon Department of Fish and Wildlife; Oregon Coast Aquarium; California Department of Fish and Game