Calico Scallop (Atlantic Calico Scallop)
Phylum: Mollusca, Class: Bivalvia, Order: Pectinida, Family: Pectinidae, Genus: Argopecten, Species: Argopecten gibbus · Pectinidae (Scallop family) · Bivalve (two-shelled clam), whole single valve, fan or disc shape
Species
Argopecten gibbus
Shell Type
Bivalve (two-shelled clam), whole single valve, fan or disc shape
Family
Pectinidae (Scallop family)
Size
Approximately 1 inch to 1.5 inches in diameter, which is typical for an adult Calico Scallop. The species generally ranges from 1 to 2 inches.
Color & Pattern
Mottled pattern featuring warm reddish-brown and orange patches over a creamy-white or yellowish base, typical of the calico morph. Colors appear natural and glossy with well-defined radial ribs.
Rarity
Common (frequently found washed ashore on beaches within its geographic range, especially after storms).
Habitat
Shallow marine waters, typically found in sandy areas, shell gravel, and seagrass beds from the low 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, and the Caribbean Sea.
Description
A charming and brightly patterned bivalve featuring approximately 18 to 21 strong, rounded radial ribs. The shell is nearly equilateral with characteristic unequal ears (auricles) at the hinge line. The exterior texture is slightly ridged and sturdy, showcasing a vibrant mosaic of reddish-brown splotches resembling a calico cat's coat.
Key Features
Nearly symmetrical rounded fan shape, prominent radial ribs (usually around 20), unequal wing-like ears at the hinge, and a colorful mottled reddish-brown and white pattern.
Collector Value
Low to moderate commercial value, but highly popular among casual beachcombers and beginner shell collectors due to their colorful patterns. Usually valued at under a dollar individually, but cherished as a classic keepsake.
Condition Notes
Good to Fine condition. The single valve is mostly intact with minor wear along the ventral margin, retaining its natural glossy sheen and bright coloration with minimal fading.
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, allowing them to escape predators like starfish.
Ecological Role
Serves as an important prey species for various marine predators including sea stars, rays, and carnivorous gastropods. They are filter feeders that help maintain water clarity in marine ecosystems.
Similar Species
Bay Scallop (Argopecten irradians), which tends to be slightly larger with flatter ribs and is typically found in shallower estuary grass beds rather than deeper offshore waters.
Beach Finding Tips
Look along high tide swash lines on Florida and Gulf Coast beaches, particularly after strong offshore winds or storms. Finding a matched pair (butterfly shell) is an exciting bonus.