The Scallop (Chlamys opercularis) is a small marine (saltwater) bivalve mollusc. It is also called a Clam, but it is not a true clam (a true clam does not live near the bottom of the ocean).

The Scallop has a white-creamy-yellowish-brown shell, called a mantle, with bilateral symmetry – its two valves are the same – connected by two hinge-type adductor muscles that enable it to open and close. Near the hinge are auricles. Auricles, like ears, are triangular protusions. The mantle has many ridges, called ribs, that fan out from the hinge. It has a foot which helps it to bury itself on the ocean floor.

The Scallop has 10–100 very small eyes along the edge of its mantle, which can detect light and motion. Each eye has a lens, a two-layered retina, and a concave mirror.

Scallop

The Scallop occasionally produces pearls, but they do not have the nacre that makes pearls iridescent, so they are dull and small.

It measures about 4 centimetres (1.5 inches) in length.

The Scallop is native to all oceans of the world, with most of them in the Indian Ocean and the Pacific Ocean. It is coastal, preferring shallow water, although some are found in deep waters. It lives on the bottom of the ocean floor, so it is benthic.

It feeds on plankton in the sea water. It is a filter feeder, which means that it strains water by opening its shell, eating only edible matter.

The Scallop can swim for short distances. It is regarded as ‘free-living’ because it is not attached to a rock, or other material.

The lifespan of the Scallop is about 20 years.

Scallop (centre)

Photographer: Martina Nicolls

Martina Nicolls: SIMILAR BUT DIFFERENT IN THE ANIMAL KINGDOM