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 valve, fan shape
Species
Argopecten gibbus
Shell Type
Bivalve (two-shelled), whole shell valve, fan shape
Family
Pectinidae (Scallop family)
Size
Approximately 1 inch in length and width, which is slightly smaller than average. Adults typically range from 1 to 2.5 inches.
Color & Pattern
Vibrant orange base coloration with subtle mottled or banded patterns radiating from the umbo. The colors are natural and well-preserved. Fine, pale radial ribs are visible across the exterior surface.
Rarity
Very Common, frequently found washed up on beaches throughout its range, particularly after storms.
Habitat
Shallow subtidal marine environments, typically found in sandy bottoms, shell gravel, and seagrass beds 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 South America, very common off the coast of Florida.
Description
A charming and compact bivalve, this single valve of an Atlantic Calico Scallop exhibits a classic fan shape with evenly spaced radial ribs. The surface is adorned with a warm orange hue, showing delicate texture and fine growth lines. The auricles (ears) near the hinge are slightly asymmetrical, which is typical for the species.
Key Features
Nearly equilateral fan shape, distinct radial ribs (typically 18 to 22), asymmetrical ears at the hinge line, and vibrant mottled or solid color variations.
Collector Value
Low to moderate commercial or monetary value due to its abundance, but highly prized by beginner beachcombers for its bright colors and pleasing symmetry. Typically sold in bulk in shell shops or used in shellcraft.
Condition Notes
Good condition. The valve is largely intact with minimal edge wear, vibrant natural color retention, and no major predator bore holes. Collectibility grade: Good to Fine.
Interesting Facts
Scallops are among the few bivalves that can actively swim by rapidly clapping their valves together to expel water, allowing them to escape predators like sea stars and crabs. They also possess dozens of simple blue eyes along the mantle edge.
Ecological Role
Calico scallops serve as important filter feeders, improving water clarity, and form a crucial food source for various marine predators including fish, rays, sea turtles, and marine mammals.
Similar Species
Rough Scallop (Argopecten irradians), which tends to be slightly larger with a more rounded profile and fewer, coarser ribs compared to the finer ribbing of the Calico Scallop.
Beach Finding Tips
Look along high-tide wrack lines on sandy ocean-facing beaches, especially after storms or strong onshore winds. Early morning just after high tide yields the best finds.