Atlantic Calico Scallop (also known simply as Calico Scallop)
Phylum: Mollusca, Class: Bivalvia, Order: Pectinida, Family: Pectinidae, Genus: Argopecten, Species: Argopecten gibbus · Pectinidae (Scallop family) · Bivalve (two-shelled), whole shell, fan-shaped
Species
Argopecten gibbus
Shell Type
Bivalve (two-shelled), whole shell, fan-shaped
Family
Pectinidae (Scallop family)
Size
Approximately 1 to 1.5 inches, which is average for this species. Adults typically range from 1 to 2.5 inches.
Color & Pattern
Vibrant patterns of reddish-brown, orange, and purple mottling or zig-zag bands over a whitish or cream-colored background, creating the calico appearance. Colors are natural and retain bright contrast.
Rarity
Very Common, frequently washed up on beaches throughout its range, especially after storms.
Habitat
Shallow subtidal waters, typically found in sandy areas, shell gravel, and seagrass beds from the low intertidal zone down to depths of about 160 feet. Marine species.
Geographic Range
Western Atlantic Ocean, ranging from North Carolina south through Florida, the Gulf of Mexico, the Caribbean, and down to South America.
Description
A charming and brightly patterned bivalve featuring a nearly equilateral, fan-shaped outline with distinct radial ribs. The exterior showcases an attractive patchwork of warm autumn tones, while the interior is glossy white with a touch of purple near the hinge. The margins are crenulated to match the external ribs.
Key Features
Nearly symmetrical rounded fan shape, prominent and well-defined radial ribs (usually around 18-22), unequal 'ears' (auricles) at the hinge line, and distinctive calico mottling pattern.
Collector Value
Low to moderate commercial value; widely sold in shell shops and craft stores. Prized by beginning beachcombers for their bright colors, though common specimens hold little monetary value.
Condition Notes
Good condition with intact margins, bright natural coloration, and minor wear typical of beach-collected specimens. Graded as 'Good' to 'Fine' collectibility.
Interesting Facts
Unlike many bivalves, calico scallops are capable of swimming by rapidly clapping their valves together to expel water, allowing them to escape predators like starfish.
Ecological Role
Serves as an important food source for various marine predators including fish, rays, crabs, and sea stars. They are filter feeders that help maintain water clarity in coastal ecosystems.
Similar Species
Atlantic Bay Scallop (Argopecten irradians), which is typically slightly larger, less inflated, and has fewer, flatter ribs.
Beach Finding Tips
Look along high tide wrack lines on sandy beaches in Florida and the southeastern United States, especially following offshore winds or storms.