Calico Scallop (Atlantic Calico Scallop)
Phylum: Mollusca, Class: Bivalvia, Order: Pectinida, Family: Pectinidae, Genus: Argopecten, Species: A. gibbus · Pectinidae (Scallop family) · Bivalve (Fan-shaped single valve)
Species
Argopecten gibbus
Shell Type
Bivalve (Fan-shaped single valve)
Family
Pectinidae (Scallop family)
Size
The specimen appears to be approximately 1.5 to 2 inches (38-50mm) in diameter. This is a typical adult size for the species, which generally caps at 3 inches.
Color & Pattern
Base color is a creamy white to pale pink. It features distinctive mottled patterns of rose-pink and light brown arranged in irregular blotches and bands. The colors are slightly muted, suggesting it may have been sun-bleached on the beach.
Rarity
Very Common
Habitat
Subtidal marine environments; typically found on sandy or shelly substrates in moderately shallow water (10 to 120 feet deep).
Geographic Range
Western Atlantic, from North Carolina through the Gulf of Mexico and the Caribbean to Brazil.
Description
An attractive, fan-shaped shell with a deeply convex (rounded) profile. The surface is sculpted with 19 to 21 distinct radiating ribs. The margins are scalloped where the ribs meet the edge of the shell. This specimen is a single 'upper' valve.
Key Features
Equilateral fan shape; 19-21 rounded radiating ribs; mottled 'calico' color pattern; more convex (inflated) than the similar Atlantic Bay Scallop.
Collector Value
Minimal financial value ($1-$5) due to high abundance, but highly desirable for craft enthusiasts and beginners for its beautiful patterns.
Condition Notes
Good condition. The shell maintains its structural integrity and most of its color. There is minor erosion at the umbo (beak) and slight fading from UV exposure. No visible predatory drill holes.
Interesting Facts
The living animal has dozens of tiny, bright blue eyes along the edge of its mantle and uses jet propulsion by rapidly clapping its valves to escape predators like sea stars.
Ecological Role
Suspension feeder that filters plankton and organic matter from the water. They are a vital food source for crabs, octopods, and large gastropods.
Similar Species
Argopecten irradians (Atlantic Bay Scallop) which is usually darker brown/grey and less convex, and Nodipecten nodosus (Lion's Paw) which is much larger and has knobbed ribs.
Beach Finding Tips
Best found after storms or high tides on Gulf Coast beaches (like Sanibel Island) or the Florida Atlantic coast. Look for splashes of pink in the shell drift line.