Calico Scallop (also known as the Little 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-shaped disc
Species
Argopecten gibbus
Shell Type
Bivalve (two-shelled clam), whole single valve, fan-shaped disc
Family
Pectinidae (Scallop family)
Size
Approximately 1 inch in width, which is average for this species. Adults typically range from 1 to 2.5 inches.
Color & Pattern
Vibrant mix of reddish-orange, pink, and white blotches arranged in a mottled 'calico' pattern radiating from the umbo. Colors appear natural and reasonably well-preserved, though showing minor sun-fading typical of beach-cast specimens.
Rarity
Common, frequently found washed ashore by beachcombers in suitable regions, especially after storms.
Habitat
Shallow marine waters, typically found in sandy areas, seagrass beds, and soft bottoms from the low intertidal zone down to depths of about 150 feet.
Geographic Range
Western Atlantic Ocean, ranging from North Carolina through the Gulf of Mexico, the Caribbean, and down to northern South America.
Description
A charming, fan-shaped bivalve featuring strong, rounded radial ribs (approximately 18 to 22) extending from the beak to the margin. The margins are scalloped and interlocking, showcasing a vibrant reddish-orange mottled exterior.
Key Features
Nearly equilateral fan shape, prominent radial ribs, distinct asymmetrical ears (auricles) at the hinge line, and characteristic brightly mottled reddish-orange and white coloration.
Collector Value
Low to moderate commercial value. Highly popular among casual beachcombers and beginner shell collectors for their bright colors, but generally too common for high-end specialist collections unless part of a color-variation display.
Condition Notes
Fair to Good condition. It is a single intact valve rather than a matching paired set. Shows minor edge wear and slight fading, but the structural ribs and bright coloration remain clearly defined. Collectibility grade: Good.
Interesting Facts
Unlike most bivalves that burrow or cement themselves, Calico Scallops can swim actively by rapidly clapping their valves together to expel water, allowing them to escape predators.
Ecological Role
Serves as an important prey item for various marine predators including fish, rays, sea stars, and octopuses. They filter phytoplankton from the water column, aiding in water clarity.
Similar Species
Bay Scallop (Argopecten irradians) - which tends to be slightly larger, more inflated, and often possesses fewer, broader ribs; and Atlantic Spondylus, which is much spinier.
Beach Finding Tips
Look along shell-rich sandy beaches after heavy winds, high tides, or offshore storms. Scan the high-tide wrack line where light, buoyant bivalve shells tend to concentrate.