A limited number of these scallops are harvested by divers or by narrow trawls off the west coast of Canada.

The spiny scallop lives on the seabed in the sublittoral zone between low tide mark and a depth of 150 metres (490 ft), on soft sediment or on rock, particularly in areas with a strong current.

The shell is composed of two valves, each of which is convex and has a small number of broad ribs covered with blunt spines.

The background colour is white with radial bands of pale purple and the right valve, which is usually underneath, is paler than the left.

Some bivalve shells have large "cardinal" teeth on the hinge immediately below the umbone, but the spiny scallop does not.

The glossy white interior of the spiny scallop's shell often has a purplish blotch near the umbone, not present in the Pacific pink.

It is found on the seabed in areas of sand, gravel or crushed shell and among boulders to a depth of about 150 metres (490 ft).

[8] It is unclear what the purpose of these is but they may serve to help orient the scallop with regard to the current for optimal feeding.

[7] When the spiny scallop's valves are parted for feeding and respiration, many tentacles protrude from each edge of the mantle.

The longer ones have sensitive chemoreceptor cells at their tip which can taste the water and allow the mollusc to react appropriately to, for example, the "smell" of a starfish, by taking evasive action.

They also seem to be able to detect the size and speed of particles moving past the bivalve in the current, enabling it to open its valves wide to feed when conditions are suitable.

Each time the valves close, water is expelled through a gap in the mantle on the dorsal side of the hinge and the animal moves margin first, a form of jet propulsion.

In the wild it has been found that the scallops and their encrusting sponges both grow to a larger size in areas of high turbidity.

[14] However, another study showed that growth rates in scallops heavily encrusted by sponges were significantly lower than in unencumbered ones.

The boring sponge Cliona celata is a parasitic species which makes holes up to 1.5 millimetres (0.059 in) diameter in the valve.

In a survey undertaken off San Juan Islands, Washington, 144 scallops, C. hastata and C. rubida were dredged up, mostly from a depth of 90 metres (300 ft).

The encrusting sponges (mostly Mycale adhaerens) were common as were the barnacle (Balanus rostratus) and the tube worms Neosabellaria cementarium, Serpula vermicularis and Spirorbis sp.

When they are attached to a scallop they benefit from the defence response of the mollusc to threats which enables it to avoid predation.