Once they grow to about an inch or so in diameter, they then flap their way up into a rocky nook and begin to cement one shell to the rock. Permanently affixed, scallops grow very slowly and may take 25 years to reach 5 to 10 inches (12 to 25 cm) in diameter.

All scallops are broadcast spawners. They release eggs and sperm into the water at the same time. In Central California Rock Scallops spawn in April.

The Rock Scallop are filter feeders and rely on currents to bring plankton to them. Rock scallops are almost always found out of direct sunlight and normally have a covering of marine growth that makes them nearly indistinguishable in with the surrounding rock.