Calico Scallop (Alternative common names: Atlantic Calico Scallop)
Phylum: Mollusca, Class: Bivalvia, Order: Pectinida, Family: Pectinidae, Genus: Argopecten, Species: A. gibbus · Pectinidae (Scallop family) · Bivalve (two-shelled), whole shell, fan/disc shape
Species
Argopecten gibbus
Shell Type
Bivalve (two-shelled), whole shell, fan/disc shape
Family
Pectinidae (Scallop family)
Size
Approximately 1.5 to 2 inches in diameter, which is typical for adult specimens of this species. Adults generally range between 1 and 2.5 inches.
Color & Pattern
Pale cream to off-white base color with subtle warm golden-yellow and peach tones near the umbo and margins. The color appears smooth, slightly worn, but natural, lacking the distinct dark mottled calico markings sometimes seen in this species due to sun-bleaching or natural color variations.
Rarity
Common, frequently found washed ashore on beaches within its geographic range.
Habitat
Found in shallow marine waters, typically ranging from low tide mark down to depths of about 150 feet. They prefer sandy or shelly substrates, often found in areas with seagrass beds.
Geographic Range
Western Atlantic Ocean, ranging from North Carolina south through Florida, the Gulf of Mexico, the Caribbean, and down to South America.
Description
A classic fan-shaped bivalve shell with distinct, evenly spaced radial ribs and prominent, symmetrical auricles (ears) at the hinge. The exterior surface has a slightly smooth, polished texture from wave action, displaying a charming gradient of soft cream and warm golden-amber hues.
Key Features
Equilateral fan shape, rounded ribs radiating from the beak (umbo), well-developed symmetrical ears on either side of the hinge, and a moderately inflated valve structure.
Collector Value
Low to moderate commercial value. While widely collected by beachcombers and sold in shell shops, exceptional color morphs can be more desirable. Typical individual value is minimal, making them wonderful starter shells or craft materials.
Condition Notes
Good condition. The valves are intact with minor natural wear on the surface features due to wave action, showing smooth rounded ribs rather than sharp edges. No major chips or predator bore holes visible. Grade: Good.
Interesting Facts
Scallops are unique among bivalves because they can swim actively by rapidly clapping their shells together to expel water, using a row of dozens of tiny bright blue eyes along their mantle edge to detect light and shadow.
Ecological Role
Scallops are important filter feeders, helping to clean the water column. They serve as a vital food source for numerous marine predators including sea stars, crabs, rays, and carnivorous gastropods.
Similar Species
Atlantic Bay Scallop (Argopecten irradians), which tends to have a slightly more flattened profile and coarser ribs, and the Zigzag Scallop (Euvola ziczac), which is typically larger and flatter with fewer, broader ribs.
Beach Finding Tips
Look along high-tide wrack lines on sandy ocean beaches following stormy weather or strong onshore winds. Low tide is the best time to comb the beach for unbroken specimens.