About Argopecten gibbus (Linnaeus, 1758)
This species, commonly known as the Atlantic calico scallop, reaches a maximum width of up to three inches. It is similar in shape and shell sculpturing to the Atlantic bay scallop. Both of its shell valves are cupped, and like all scallops, the shell near the hinge extends into distinct "ears". The shell of this species has around 20 radial ribs, which are sometimes roughened by growth lines. The exterior of the upper (left) valve is most often mottled purple over a cream background. The lower (right) valve is typically whitish, with small reddish or purple spots along its sides. The shell interior is white, and often has beige coloring on the "ears" and top edge. The species' striking shell color inspired its common name: for many years in the United States, "calico" referred to an inexpensive, colorful fabric printed with small flower patterns. This common name is no longer in common use in the US. The Atlantic calico scallop's range extends from Delaware to Brazil. It is still sometimes caught commercially. This species does not live in bays; instead, it inhabits open ocean waters up to 100 feet deep. Empty shells are commonly found washed up on ocean beaches. Calico scallops can be distinguished from related species by valve color and shell morphometry. Two other scallop species live in Florida's Indian River Lagoon. The first is the bay scallop Argopecten irradians, which generally has a uniform gray to gray-brown coloration, and a distinctly convex right (lower) valve. The second is the rough scallop Aequipecten muscosus, which has unequal "ears" and sharp scales on the lower surface of its ribs. The rough scallop's color ranges from yellow and orange to red or brownish.
