Atlantic Calico Scallop (Calico Scallop)
Phylum: Mollusca, Class: Bivalvia, Order: Pectinida, Family: Pectinidae, Genus: Argopecten, Species: Argopecten gibbus · Pectinidae (Scallop family) · Bivalve, whole single valve, fan-shaped
Species
Argopecten gibbus
Shell Type
Bivalve, whole single valve, fan-shaped
Family
Pectinidae (Scallop family)
Size
Approximately 1.5 to 2 inches in width, which is average for an adult specimen of this species. Adults typically range between 1.5 and 2.5 inches.
Color & Pattern
Displays a classic calico pattern with mottled reddish-pink and white coloration radiating in broken bands and patches from the umbo toward the ventral margin. The colors are largely natural with slight fading near the edges, showing typical beach-worn exposure.
Rarity
Common, frequently found washed ashore on beaches within its geographic range, especially following storms.
Habitat
Found in marine environments, specifically in shallow subtidal waters to depths of about 150 feet, preferring sandy or shelly bottoms, often associated with seagrass beds.
Geographic Range
Western Atlantic Ocean, ranging from North Carolina down through Florida, the Gulf of Mexico, the Caribbean, and south to Brazil.
Description
An attractive, roughly symmetrical fan-shaped bivalve with numerous prominent, rounded radial ribs extending from the hinge. It features unequal auricles (ears) at the hinge line, typical of scallops, and a delicate scalloped margin.
Key Features
Rounded radial ribs (typically around 18-21), unequal ears at the hinge, and a mottled reddish-brown or pinkish calico color pattern distinguishing it from solid-colored relatives.
Collector Value
Low to moderate commercial and collector value. They are very popular for shell crafts, home decor, and beginner shell collections due to their appealing colors, though individual beach-found valves are rarely expensive.
Condition Notes
Good condition. The exterior is relatively intact with clear ribbing and original color patterns, though showing minor wear and slight fading along the margins. No major fractures or boring holes are visible. Collectibility grade: Fine.
Interesting Facts
Unlike many bivalves that burrow or cement themselves, calico scallops are capable of swimming short distances by rapidly clapping their valves together to expel water. They also possess dozens of simple blue eyes along the mantle edge.
Ecological Role
Calico scallops are important filter feeders, helping to clear suspended matter from the water column. They serve as a vital food source for numerous marine predators including fish, crabs, and sea stars.
Similar Species
Bay Scallop (Argopecten irradians), which tends to be slightly larger, more inflated, and often possesses fewer, broader ribs (usually 17 or fewer).
Beach Finding Tips
Look along Atlantic and Gulf beaches of Florida and the southern United States, particularly after high tides or storms. Scour the high-tide wrack line where light shells accumulate.