A scallop is a bivalve mollusk with a somewhat rounded, fanlike shell having "scalloped" edges and radiating ribs. Many species of scallops can be found in every sea, most of which are edible such as the Asian moon scallop (Amusium pleuronectes) and Edible bay scallop (Argopecten irradians). The edible part is the large white muscle in the middle of its body that connects the two valves. In Europe, however, the other parts such as the mantle and gonads are also prepared in delicious baked dishes.

The scallop usually rests at the bottom of the sea, but when it is in danger or preyed upon by other marine animals, it can swim rapidly using the movement of its shells. The moon scallop developed very light and smooth shells that can be propelled through the water with little effort. A scallop can jet through the water for several feet by rapidly snapping (opening and closing) its shell and shooting water out behind. It does not have much ability to control the direction of its movements.