Calico Scallop (also known as the Atlantic Calico Scallop)
Phylum: Mollusca, Class: Bivalvia, Order: Pectinida, Family: Pectinidae, Genus: Argopecten, Species: Argopecten gibbus · Pectinidae (Scallop family) · Bivalve (two-shelled clam), whole shell, fan/disc shaped
Species
Argopecten gibbus
Shell Type
Bivalve (two-shelled clam), whole shell, fan/disc shaped
Family
Pectinidae (Scallop family)
Size
Approximately 1.5 inches in width, which is typical for an adult Calico Scallop. Adults generally range from 1 to 2.5 inches.
Color & Pattern
The specimen shows heavy sun-bleaching with a predominantly off-white or cream base color and faint traces of reddish-brown mottling. Natural specimens typically display vibrant patterns of red, brown, purple, or orange speckles and zig-zags resembling calico fabric, but this shell is severely weathered.
Rarity
Very Common. These shells wash ashore by the thousands along southeastern US and Gulf beaches, though finding a pristine, brightly colored whole specimen takes more searching.
Habitat
Found in shallow subtidal waters, typically on sandy or shelly substrates, often associated with seagrass beds from the low-tide line down to 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
A classic fan-shaped bivalve with prominent, rounded radial ribs radiating from the umbo (hinge). The margins are scalloped and symmetrical, displaying equal or nearly equal auricles (ears) at the hinge line. The texture is chalky and worn due to marine tumbling and beach weathering.
Key Features
Equilateral fan shape, rounded radiating ribs (typically numbering around 18 to 22), and slightly asymmetrical ears at the straight hinge line characteristic of the genus Argopecten.
Collector Value
Low commercial or collector value due to commonality and worn condition. Mostly collected casually by beachcombers or used in shell crafts.
Condition Notes
Fair to Poor condition. The shell is structurally intact as a single valve, but it is heavily sun-bleached, worn down, and exhibits a few small boring sponge or predator holes near the center. Original color patterns are mostly faded away. Collectibility grade: Fair.
Interesting Facts
Unlike most clams, scallops are capable of swimming by rapidly clapping their valves together to expel water jets, allowing them to escape predators like sea stars.
Ecological Role
Scallops serve as an important food source for many marine predators, including fish, rays, sea turtles, and crabs. They are filter feeders that help maintain water clarity.
Similar Species
Bay Scallop (Argopecten irradians), which tends to have fewer ribs (usually 17 or fewer) and a more northern distribution, and the Zigzag Scallop (Euvola ziczac).
Beach Finding Tips
Look along high-tide wrack lines on sandy ocean-facing beaches in Florida and the Gulf coast, especially after storms or strong onshore winds.