The spiny scallop lives on the seabed in the sublittoral zone between low tide mark and a depth of , on soft sediment or on rock, particularly in areas with a strong current. It is a filter feeder, sieving microscopic algae from water that passes through its gills. It is preyed on by starfish, octopuses and sea otters. It can detect predators by smell and by sight and can swim away from them by opening and closing its valves. Other organisms often grow on the exterior of its shell and it often forms a symbiotic relationship with an encrusting sponge which grows on the upper valve and helps protect it from predators.
