Scallop, an edible mollusk related to the oyster and the clam. There are more than 200 species of scallops. They live in colonies on the ocean floor, some in shallow coastal areas and others at great depths.

ScallopsScallops live in colonies on the ocean floor.

The scallop has a bivalve shell (one composed of two parts). The shell is ribbed and rounded, with wavy edges. Depending on species, scallops are from three to eight inches (7.5 to 20 cm) wide. A common North American species, the Atlantic bay scallop, is about three inches wide. Scallop shells are used as plates and as decorative pieces.

The scallop's soft body is surrounded by a thin fold of tissue called a mantle, which lines the inside of the shell. The body, as in other mollusks, has a nervous system, a circulatory system, and a digestive system. Scallops feed on tiny plants and animals. Two rows of well-developed eyes are set into the edge of the mantle. A scallop has one large, round muscle that opens and closes its shell. This muscle is the part of the scallop that is eaten. The scallop moves through water by clapping the two parts of its shell together.

Which Bivalve Can Swim All on Its Own?

The scallop, unlike most other bivalves, can propel itself across the ocean floor. The scallop has a special muscle that lies near the center of its body. It uses this muscle to open and close its shell quickly. This forces water out of its mantle cavity, causing the scallop to move as much as 3 feet (91 centimeters).

A scallop doesn’t move very often. But when it does, it’s usually because a sea star or other predator is near. Sometimes, a scallop spurts water out of its shell to make a resting hole in the sandy ocean floor.

The Atlantic bay scallop is Argopecten irradians. Scallops are of the family Pectinidae.