Calico Scallop (Alternate names: Atlantic 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 disc
Species
Argopecten gibbus
Shell Type
Bivalve (two-shelled), whole individual valve, fan-shaped disc
Family
Pectinidae (Scallop family)
Size
Approximately 2 inches wide, which is average for an adult specimen of this species. Adults typically range between 1.5 to 3 inches.
Color & Pattern
Displays a mottled pattern of reddish-brown streaks and patches on a cream or whitish background, fading towards a pale yellowish-green apex near the hinge. Colors appear natural and somewhat sun-faded at the margins.
Rarity
Common, frequently found washed ashore on beaches within its geographic range.
Habitat
Shallow subtidal zones to moderate depths, typically found on sandy bottoms and seagrass beds in marine environments.
Geographic Range
Western Atlantic Ocean, ranging from North Carolina down through Florida, the Gulf of Mexico, and the Caribbean.
Description
An attractive, fan-shaped bivalve with approximately 18 to 20 well-defined radial ribs spanning from the umbo to the undulating margin. The surface has a fine, granular texture with distinct growth lines crossing the ribs.
Key Features
Nearly equilateral fan shape, distinctive radial ribs, unequal auricles (ears) at the hinge line, and characteristic mottled reddish-brown color pattern.
Collector Value
Low to moderate commercial and collectible value. Because they are common, they are frequently sold in shell shops or used in shell crafts rather than commanding high prices among serious collectors, though vibrant color variants are appreciated.
Condition Notes
Good condition. It is a single valve (half shell) with minor wear at the margins, retaining most of its natural coloration without major structural breakage. Collectibility grade: Good.
Interesting Facts
Scallops are unique among bivalves because they can swim by rapidly snapping their shells together to expel water, allowing them to escape predators like sea stars and crabs. They also possess dozens of simple blue eyes along the edge of their mantle.
Ecological Role
Serves as an important prey item for various marine predators including fish, rays, sea turtles, and sea stars. They are filter feeders, helping to clear suspended organic matter from the water column.
Similar Species
Atlantic Bay Scallop (Argopecten irradians), which tends to have a more rounded, deeper shell with fewer and broader ribs.
Beach Finding Tips
Best found by beachcombing along Gulf and Atlantic coasts of Florida during low tide, particularly after storms or heavy onshore winds deposit drift shells along the wrack line.