Argopecten gibbus
Medium-sized edible scallop with mottled purple and cream shell.
The Atlantic calico scallop, *Argopecten gibbus*, is a medium-sized, edible marine bivalve from the scallop family Pectinidae. It once supported a major fishery, though catches have declined in recent years.
This scallop reaches a maximum width of about three inches, with a shape and shell texture similar to the Atlantic bay scallop. Both shell halves are cupped, and, like all scallops, the shell near the hinge extends into "ears." The shell has roughly 20 radial ribs, sometimes roughened by growth lines. The upper (left) valve is typically mottled purple on a cream background, while the lower (right) valve is usually whitish with small reddish or purple spots on the sides. The interior is white, often with beige coloring on the ears and top edge. Its vivid shell color inspired the common name "calico," after an inexpensive, colorful printed fabric once common in the US, though the name is no longer used there.
The species ranges from Delaware to Brazil and is still occasionally fished commercially. It lives in open water, not bays, at depths up to 100 feet, and its shells are often found washed up on ocean beaches. Shell color and shape distinguish it from related species. In Florida’s Indian River Lagoon, the bay scallop (*Argopecten irradians*) has a uniform gray to gray-brown color and a distinctly convex right valve, while the rough scallop (*Aequipecten muscosus*) has unequal ears and sharp scales on the lower rib surfaces, with yellow, orange, red, or brownish coloring.
Quick Facts
- Genus
- Argopecten
- Species
- gibbus
Facts from the source article.
Lore & Background
The Atlantic calico scallop grows up to three inches in maximum width and is similar in shape and sculpturing to the Atlantic bay scallop. Both valves of the shell are cupped, and the shell near the hinge is extended into 'ears', as is the case in all scallops. The shell has about 20 radial ribs, which are sometimes roughened by growth lines. The exterior coloration of the upper (left) valve is most typically a mottled pattern of purple on a cream background, while the lower (right) valve is usually whitish with small reddish or purple spotting on the sides. The interior of the shell is white, often with some beige coloration on the 'ears' and top edge.
The eye-catching color of the shell gave rise to its popular name; in the US, 'calico' was for many years an inexpensive but colorful fabric printed with small flower patterns. The name is no longer in practice within the US. The species ranges from Delaware to Brazil and is still sometimes fished commercially. It is not found in bays; instead it lives in open water up to 100-foot depths. The shells are commonly found washed up on ocean beaches.
Valve color and shell morphometry distinguish calico scallops from related species. In the Indian River Lagoon in Florida, two other scallops occur: the bay scallop (Argopecten irradians), which generally has a uniform gray to gray-brown coloration with distinct convexity of the right (lower) valve; and the rough scallop (Aequipecten muscosus), which has unequal 'ears' and sharp scales on the lower surface of the ribs, with color of yellow, orange, red or brownish.
Reader's Guide
The Atlantic calico scallop was once the basis of an important fishery, though in recent years catches have been low. It is still sometimes fished commercially within its range from Delaware to Brazil. The species is notable for its distinctive shell coloration, which gave rise to its common name—'calico' referring to an inexpensive colorful fabric printed with small flower patterns, though this name is no longer in practice within the US. The scallop lives in open water up to 100-foot depths, not in bays, and its shells are commonly found washed up on ocean beaches. Identification relies on valve color and shell morphometry, distinguishing it from related species such as the bay scallop and the rough scallop, which occur in the same region. The species belongs to the family Pectinidae and is a medium-sized edible marine bivalve mollusk.
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