Calico Scallop
Phylum: Mollusca | Class: Bivalvia | Order: Pectinida | Family: Pectinidae | Genus: Argopecten | Species: Argopecten gibbus · Pectinidae (Scallop family) · Bivalve (two-shelled), whole individual valve, fan-shaped
Species
Argopecten gibbus
Shell Type
Bivalve (two-shelled), whole individual valve, fan-shaped
Family
Pectinidae (Scallop family)
Size
Approximately 1 inch in width, which is slightly smaller than average for this species. Adults typically range from 1.5 to 2.5 inches.
Color & Pattern
Featuring a whitish base adorned with distinct, irregular blotches and patches of deep reddish-purple and burgundy. The colors are natural and vibrant with sharp contrast.
Rarity
Common
Habitat
Shallow marine waters, typically found resting on sandy or shelly substrates in bays, sounds, and nearshore areas from the low intertidal zone down to moderate depths.
Geographic Range
Western Atlantic Ocean, ranging from North Carolina down through Florida, the Gulf of Mexico, and the Caribbean Sea.
Description
A charming and compact fan-shaped bivalve shell featuring strong, prominent radial ribs and rounded margins. The surface displays a smooth yet textured feel with well-defined growth lines crossing the ribs.
Key Features
Symmetrical fan shape with roughly 18-20 prominent, rounded radial ribs and slightly unequal auricles (ears) at the hinge line, coupled with the characteristic calico-style mottled red and white coloration.
Collector Value
Inexpensive and widely available, making it a popular species for beginner collectors, shell crafts, and educational displays. Typical individual valves sell for mere cents to a dollar.
Condition Notes
Good condition with intact margins, minimal wear, and bright coloration. It is a solid single valve suitable for a beginner or intermediate collection, grading as Fine.
Interesting Facts
Unlike many bivalves, calico scallops are capable of swimming short distances by rapidly clapping their valves together to expel water, allowing them to escape predators like starfish.
Ecological Role
Serves as an important prey item for various marine predators including fish, crabs, and sea stars. They filter feed on phytoplankton, helping to maintain water clarity in coastal ecosystems.
Similar Species
Atlantic Bay Scallop (Argopecten irradians), which tends to be slightly larger with more flattened ribs and a different overall color distribution.
Beach Finding Tips
Look along high-tide shell lines on sandy ocean-facing beaches or inside inlets, particularly after storms or windy conditions that churn up offshore grass beds and shallow bars.