Atlantic Calico Scallop (also known simply as Calico Scallop)
Phylum: Mollusca, Class: Bivalvia, Order: Pectinida, Family: Pectinidae, Genus: Argopecten, Species: A. gibbus · Pectinidae (Scallop family) · Bivalve (two-shelled), whole individual shells with a fan-like disc shape
Species
Argopecten gibbus
Shell Type
Bivalve (two-shelled), whole individual shells with a fan-like disc shape
Family
Pectinidae (Scallop family)
Size
Approximately 1 to 1.5 inches in diameter, which is average for this species. Adults typically range from 1 to 2.5 inches.
Color & Pattern
Featuring attractive pastel shades of pink, lavender, cream, and orange with subtle mottled or banded patterns typical of the species. Colors appear mostly natural with slight weathering, showing characteristic radial patterns extending from the umbo to the margin.
Rarity
Common to Very Common. These shells are frequently washed ashore intact, especially after storms.
Habitat
Shallow marine waters, typically found in sandy or shelly substrates, often amongst seagrass beds from the intertidal zone down to depths of about 150 feet.
Geographic Range
Western Atlantic Ocean, ranging from North Carolina down through Florida, the Gulf of Mexico, the Caribbean, and south to Brazil.
Description
These delightful small bivalves feature a classic fan-shaped morphology with prominent, rounded radial ribs and slightly unequal auricles (ears) at the hinge. The margins are scalloped, and the exterior surface exhibits a fine textural granularity with charming mottled coloration.
Key Features
Equilateral to slightly inequilateral fan shape, distinct radial ribs (typically around 18-22), asymmetrical ears at the hinge line, and a plump, rounded profile compared to flatter scallop species.
Collector Value
Low to moderate commercial value, highly popular among beginner beachcombers and crafters for shell art due to their vibrant colors and symmetrical beauty.
Condition Notes
Good to Fine condition. The shells are mostly intact with well-preserved colors and minimal edge chipping, though showing slight natural wear from wave action.
Interesting Facts
Scallops are among the few bivalves that can actively swim. By rapidly clapping their valves together, they expel water to jet-propel themselves away from predators like starfish.
Ecological Role
Calico scallops serve as an important prey item for various marine predators including sea stars, rays, and carnivorous gastropods. They are filter feeders, helping to clear suspended organic matter from the water column.
Similar Species
Atlantic Bay Scallop (Argopecten irradians), which tends to have a slightly more compressed shell and flatter ribs, and the Rough Scallop (Aequipecten muscosus), which has more prominent, scaly ribs.
Beach Finding Tips
Look along high-tide wrack lines on sandy ocean-facing beaches after windy days or storms. Morning low tides are ideal for spotting them amongst shell hash.