Atlantic Calico Scallop (also known as Calico Scallop)
Phylum: Mollusca, Class: Bivalvia, Order: Pectinida, Family: Pectinidae, Genus: Argopecten, Species: Argopecten gibbus · Pectinidae (Scallop family) · Bivalve (two-shelled), whole shell, fan-shaped disc
Species
Argopecten gibbus
Shell Type
Bivalve (two-shelled), whole shell, fan-shaped disc
Family
Pectinidae (Scallop family)
Size
Approximately 1.5 to 2 inches in width, which is average for this species. Adults typically range from 1.5 to 2.5 inches.
Color & Pattern
Delicate pinkish-red radial ribs fading to a creamy white translucent hinge area. The colors are natural and exhibit the classic mottled pattern typical of the species.
Rarity
Common, frequently found by beachcombers along the southeastern coast of the United States and the Gulf of Mexico.
Habitat
Shallow marine waters, typically found in sandy or shelly substrates, often in seagrass beds from the low intertidal zone down to about 160 feet.
Geographic Range
Western Atlantic Ocean, ranging from North Carolina down through Florida, the Gulf of Mexico, and the Caribbean to South America.
Description
An attractive, nearly symmetrical fan-shaped bivalve featuring numerous well-defined, rounded radial ribs. The hinge possesses distinct, short auricles (ears) characteristic of scallops, and the exterior surface displays a pleasing pastel reddish-pink coloration.
Key Features
Fan-shaped disc, distinct radial ribs (typically around 18-21), relatively equal-sized auricles (ears) at the hinge line, and a rounded ventral margin.
Collector Value
Low to moderate commercial value. While widely sold in souvenir shops and collected by hobbyists, exceptionally colorful or pristine matched pairs can be desirable for local collection displays.
Condition Notes
Good to Fine condition. The specimen is intact with minimal wear on the ribs, showing natural coloration with only slight fading. Collectibility grade is Good.
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, using a series of simple blue eyes along their mantle edge to detect motion.
Ecological Role
Calico scallops serve as an important food source for numerous marine predators, including fish, rays, sea turtles, and gulls. They are filter feeders that help maintain water clarity.
Similar Species
Bay Scallop (Argopecten irradians), which tends to be slightly larger with fewer, squarer ribs and a more northern distribution range.
Beach Finding Tips
Look along high-tide wrack lines on sandy beaches following storms or heavy onshore winds, particularly in Florida and North Carolina.