Atlantic Deep-Sea Scallop (also commonly known as sea scallop)
Phylum: Mollusca, Class: Bivalvia, Order: Pectinida, Family: Pectinidae, Genus: Placopecten, Species: Placopecten magellanicus · Pectinidae (Scallop family) · Bivalve (two-shelled), whole shell, fan-shaped disc
Species
Placopecten magellanicus
Shell Type
Bivalve (two-shelled), whole shell, fan-shaped disc
Family
Pectinidae (Scallop family)
Size
Approximately 1.5 to 2 inches wide, which is small for this species. Adult Atlantic sea scallops typically range from 3 to 6 inches or more in diameter.
Color & Pattern
Pale off-white to creamy base color with subtle hints of peach or orange near the umbo and margins. The colors appear slightly sun-bleached and worn from wave action. The exterior shows delicate radiating ribs typical of juvenile or worn adult scallops.
Rarity
Common in deep waters and commercial fisheries, but whole, undamaged small specimens occasionally wash up on northern beaches, making them moderately easy to find with some searching.
Habitat
Marine species typically found in deeper subtidal waters, ranging from the shallow subtidal zone down to depths of over 100 meters. Prefers firm substrates of sand, gravel, or shell rubble.
Geographic Range
Northwest Atlantic Ocean, ranging from the Strait of Belle Isle, Newfoundland down to Cape Hatteras, North Carolina.
Description
A classic fan-shaped bivalve shell featuring a rounded ventral margin and straight hinge line with distinct auricles (ears). The exterior displays numerous fine, regular radiating ribs that extend from the prominent umbo to the outer edge. The surface texture is somewhat smooth due to wear, showcasing a delicate, light coloration with soft orange-peach gradients.
Key Features
Equivalve to slightly inequivalve fan shape, prominent straight hinge line with equal or nearly equal-sized ears (auricles), fine radiating ribs, and a distinct central umbo at the apex of the hinge.
Collector Value
Low to moderate commercial and collectible value. While commercially vital for food, common beach-worn specimens hold little monetary value but remain popular souvenir finds for casual beachcombers.
Condition Notes
Fair to Good condition. The shell is intact as a single valve, though it shows signs of beach wear with smoothed ribs, minor edge chipping, and sun-bleached fading of the original brighter coloration. No major boring holes are visible.
Interesting Facts
Scallops are among the few bivalves that can swim. They do this by rapidly snapping their valves together to jet water out from beside the hinge, allowing them to escape predators like starfish. They also possess dozens of simple blue eyes along the edge of their mantle that can detect light and motion.
Ecological Role
Scallops serve as an important filter feeder in benthic marine ecosystems, helping to clear the water column of phytoplankton and suspended matter. They are a primary food source for numerous marine predators, including sea stars, crabs, octopuses, and bottom-feeding fish. Commercial harvesting is heavily regulated through quotas and size limits.
Similar Species
Calico Scallop (Argopecten gibbus) and Bay Scallop (Argopecten irradians), which are generally smaller, possess more prominent and coarser ribs, and feature much brighter, contrasting color patterns.
Beach Finding Tips
Look along northern Atlantic beaches, especially after storms or heavy high tides. Search the shell drift lines near the high tide mark where lightweight bivalve shells tend to concentrate in the sand.