Calico Scallop (Alternative common names: Atlantic Calico Scallop)
Phylum: Mollusca, Class: Bivalvia, Order: Pectinida, Family: Pectinidae, Genus: Argopecten, Species: Argopecten gibbus · Pectinidae (Scallop family) · Bivalve (two-shelled mollusk), shell fragment, fan shape
Species
Argopecten gibbus
Shell Type
Bivalve (two-shelled mollusk), shell fragment, fan shape
Family
Pectinidae (Scallop family)
Size
Approximately 0.75 inches for the visible fragment. Complete adults of this species typically range between 1.5 to 2.5 inches in diameter.
Color & Pattern
Displays a mottled pattern of purplish-brown and white streaks radiating from the umbo, characteristic of the 'calico' coloration. Colors appear natural and reasonably well-preserved.
Rarity
Very Common
Habitat
Found in shallow marine waters, typically in sandy substrates, seagrass beds, or offshore shell gravel, ranging from the intertidal zone down to moderate depths.
Geographic Range
Western Atlantic Ocean, ranging from North Carolina through the Gulf of Mexico, Florida, and the Caribbean.
Description
This is a fragment of a bivalve shell featuring rounded radial ribs and a symmetrical fan-like structure typical of scallops. The exterior showcases distinct mottled color markings that give the shell its calico appearance.
Key Features
Rounded radial ribs, slight inequilateral bivalve curvature, and characteristic calico mottling of reddish-brown or purple over a white base.
Collector Value
Very low due to the fragmentary and incomplete nature of the specimen. It holds little to no monetary value but serves as a pleasant beach keepsake.
Condition Notes
This specimen is a broken fragment lacking the complete margin and hinge area. Surface is slightly worn from wave action, placing it in poor condition for a whole-shell collection.
Interesting Facts
Scallops are unique among bivalves for their ability to swim actively by clapping their valves together to expel water, and they possess dozens of simple blue eyes along the mantle edge.
Ecological Role
Scallops serve as an important food source for various marine predators including fish, rays, and sea stars, and contribute to benthic-pelagic coupling through filter feeding.
Similar Species
Atlantic Bay Scallop (Argopecten irradians), which tends to have deeper ribs and a more northern distribution.
Beach Finding Tips
Look along shell lines on sandy Atlantic and Gulf of Mexico beaches, especially after storms or high tides.