Calico Scallop (also known as the Calico Clam)
Phylum: Mollusca, Class: Bivalvia, Order: Pectinida, Family: Pectinidae, Genus: Argopecten, Species: Argopecten gibbus · Pectinidae (Scallop family) · Bivalve (two-shelled clam), whole shell, asymmetrical fan-shaped valve
Species
Argopecten gibbus
Shell Type
Bivalve (two-shelled clam), whole shell, asymmetrical fan-shaped valve
Family
Pectinidae (Scallop family)
Size
Approximately 1 to 1.5 inches in length, which is typical for an adult Calico Scallop. Adults generally range from 1 to 2.5 inches.
Color & Pattern
Featuring a striking and vibrant pattern of mottled or zigzagging brownish-orange, reddish, or purplish-brown spots and patches set against a creamy white or off-white base. The colors are entirely natural and glossy.
Rarity
Common, frequently found washed ashore on beaches throughout its native range, particularly along the coast of Florida.
Habitat
Shallow marine waters, typically found living on sandy bottoms, shell hash, or in seagrass beds from the low 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, the Caribbean, and south to parts of South America.
Description
A charming and attractive bivalve showcasing a rounded, fan-like morphology with distinct radiating ribs and characteristic asymmetrical "ears" along the hinge line. The exterior surface is smooth yet subtly ribbed, polished by wave action, and displays a lively calico pattern reminiscent of calico fabric.
Key Features
Unequal or asymmetrical ears (auricles) at the hinge, a slightly convex rounded valve profile, and the characteristic mottled reddish-brown speckles or zigzag markings over a white background.
Collector Value
Modest collector value. While very common and inexpensive, specimens with particularly bright colors or pristine patterns are popular among beginner and intermediate shell collectors and are staples in shell shops.
Condition Notes
The depicted single valve is in excellent, highly collectible condition with intact margins, bright unfaded natural coloration, and a smooth, glossy exterior finish, grading as Fine to Gem.
Interesting Facts
Unlike many other bivalves, Calico Scallops are capable of swimming short distances by rapidly clapping their valves together to expel water, allowing them to escape predators like starfish and rays.
Ecological Role
Acts as an important filter feeder in coastal marine ecosystems, helping to clear suspended matter from the water column, and serves as a vital food source for numerous fish, crabs, and sea stars.
Similar Species
Atlantic Bay Scallop (Argopecten irradians), which tends to have deeper ribs and a slightly more symmetrical shape, and the Zigzag Scallop (Euvola ziczac), which is typically larger and flatter.
Beach Finding Tips
Look along sandy ocean-facing beaches after storms or strong onshore winds, particularly at low tide along the Gulf and Atlantic coasts of Florida.