Calico Scallop (also known as Atlantic Calico Scallop)
Phylum: Mollusca, Class: Bivalvia, Order: Pectinida, Family: Pectinidae, Genus: Argopecten, Species: Argopecten gibbus · Pectinidae (Scallop family) · Bivalve (two-shelled), whole shell, fan-shaped disc
Species
Argopecten gibbus
Shell Type
Bivalve (two-shelled), whole shell, fan-shaped disc
Family
Pectinidae (Scallop family)
Size
Approximately 2 inches in width and length, which is a very typical size for an adult specimen of this species. Adults normally range between 1.5 to 2.5 inches.
Color & Pattern
Displays a vibrant mottled pattern featuring warm reddish-orange, brown, and cream tones radiating outward from the umbo. The colors are entirely natural and well-preserved with distinct radial striations.
Rarity
Common
Habitat
Found in shallow marine waters, typically living on sandy or shelly substrates, often associated with seagrass beds from the intertidal zone down to depths of about 150 feet.
Geographic Range
Western Atlantic Ocean, ranging from North Carolina down through Florida, the Gulf of Mexico, and the Caribbean Sea.
Description
An attractive, symmetrically fan-shaped bivalve shell with distinctly rounded ears at the hinge. The exterior features numerous fine, rounded radial ribs crossed by faint concentric growth lines, culminating in a scalloped margin. The coloration is a bright mix of orange and mottled reddish-brown patterns.
Key Features
Nearly equivalve, rounded fan shape with pronounced, equal-sized auricles (ears) at the straight hinge line, numerous fine radial ribs (typically around 18 to 22), and a vibrant mottled exterior color pattern.
Collector Value
Inexpensive and widely available in shell shops, making it a popular starter piece for beginner shell collectors and a favorite for crafting due to its bright colors and sturdy form.
Condition Notes
Fine to Gem condition. The shell is fully intact with crisp margins, strong natural coloration, no major chips on the delicate edges, and very little wear on the hinge structure.
Interesting Facts
Unlike many bivalves that burrow or cement themselves, Calico Scallops are capable of active swimming by rapidly clapping their valves together to expel water, helping them escape predators like sea stars.
Ecological Role
Acts as an important filter feeder in coastal marine ecosystems, helping to clear suspended particulate matter from the water column while serving as a key food source for fish, rays, and sea turtles.
Similar Species
Bay Scallop (Argopecten irradians), which tends to have slightly flatter shells with fewer, broader ribs and different geographic distribution preferences.
Beach Finding Tips
Look along drift lines on sandy Atlantic and Gulf beaches following rough weather or high tides. They are often washed ashore in large numbers, particularly near inlets and grass flats.