Sea Scallop (also known as the Atlantic Deep-Sea Scallop or Giant Scallop)
Phylum: Mollusca, Class: Bivalvia, Order: Pectinida, Family: Pectinidae, Genus: Placopecten, Species: P. magellanicus · Pectinidae (Scallop family) · Bivalve (two-shelled). These are single valves (one upper, one lower). Shape: Circular/Disc-like with characteristic auricles (ears) at the hinge.
Species
Placopecten magellanicus (100% confidence)
Shell Type
Bivalve (two-shelled). These are single valves (one upper, one lower). Shape: Circular/Disc-like with characteristic auricles (ears) at the hinge.
Family
Pectinidae (Scallop family)
Size
Approximately 4-5 inches in diameter. Adult Sea Scallops can grow up to 8 inches, making these large sub-adult or average adult specimens for the New York region.
Color & Pattern
Specimen 1 (Top) is the lower/right valve, which is naturally off-white to creamy white. Specimen 2 (Bottom) is the upper/left valve, showing the characteristic reddish-pink to brownish-purple pigmentation with concentric growth lines and faint radiating rays.
Rarity
Very Common. They are a staple of the Atlantic fishing industry and their shells are frequently washed up on beaches after storms or discarded by commercial fisheries.
Habitat
Found in cold temperate waters on sandy or gravelly bottoms. They typically live in depths between 60 to 600 feet, but can be found in shallower waters in the northern parts of their range.
Geographic Range
Northwest Atlantic Ocean, ranging from the north coast of Newfoundland to Cape Hatteras, North Carolina. They are extremely common off the coast of Long Island, NY.
Description
A large, relatively flat bivalve with a nearly circular outline. The surface is textured with very fine radiating striae and distinct concentric growth rings. The shells lack the deep, heavy ribs found in Bay Scallops, appearing much smoother and thinner. The 'ears' at the hinge are nearly equal in size.
Key Features
Smoothness compared to other scallops; large size; the distinct color difference between the white lower valve and the pigmented upper valve; very fine, almost microscopic radiating lines rather than deep ridges.
Collector Value
Low monetary value ($1-$5) due to high abundance. However, they are highly desired by crafters and amateur collectors for their beautiful circular symmetry and the vibrant pink/purple shades of the upper valves.
Condition Notes
Fair to Good. These specimens show some edge chipping and minor erosion typical of beach-found shells. The colors are well-preserved, though some staining from iron/sand is visible near the hinge (umbo). Grading: Fine.
Interesting Facts
Unlike many bivalves, Sea Scallops can swim short distances by rapidly clapping their shells together to create jet propulsion. They have dozens of tiny, bright blue eyes along the edge of their mantle that detect light and movement.
Ecological Role
Active filter feeders that help maintain water clarity by consuming phytoplankton. They are a vital food source for sea stars, crabs, and bottom-dwelling fish, and support one of the most valuable commercial fisheries in the United States.
Similar Species
Argopecten irradians (Bay Scallop) which is much smaller with deep, prominent ribs; and Pecten maximus (Great Scallop) which has one deeply convex valve and one flat valve.
Beach Finding Tips
On Long Island, look for these after a strong Nor'easter or heavy winter surf. They are most commonly found on the ocean-facing beaches (South Shore) rather than the Sound, often tangled in 'sea wrack' or kelp holdfasts.
Notes
long island my