Calico Scallop (also known as the Speckled Scallop)
Phylum: Mollusca; Class: Bivalvia; Order: Pectinida; Family: Pectinidae; Genus: Argopecten; Species: Argopecten gibbus · Pectinidae (Scallop family) · Bivalve (single valve shown, fanshaped shell)
Species
Argopecten gibbus (Confidence: 90%)
Shell Type
Bivalve (single valve shown, fanshaped shell)
Family
Pectinidae (Scallop family)
Size
Approximately 1 inch (2.5 cm) in width. Typical adult size ranges from 1 to 3 inches.
Color & Pattern
Warm reddish-pink to orange-tan base color with subtle concentric growth lines. The specimen appears slightly water-worn or beach-rubbed, giving it a soft matte finish. Classic Calico patterns usually involve speckles, but this solid-colored variant occurs frequently in beach-found specimens.
Rarity
Very Common. These are among the most frequently found shells on many Atlantic and Gulf Coast beaches.
Habitat
Found in marine environments, specifically on sandy or gravelly bottoms at depths ranging from 30 to 130 feet (10-40 meters), though they are often washed ashore in the intertidal zone.
Geographic Range
Western Atlantic Ocean, from North Carolina to Brazil, including the Gulf of Mexico and throughout the Caribbean.
Description
An attractive, roughly circular, fan-shaped valve. The shell is deeply convex (inflated) with roughly 19-22 radiating ribs. It features small 'ears' or auricles at the hinge line. The texture is characterized by ribbed sculpting that creates a scalloped edge along the margin.
Key Features
Symmetrical fan shape, roughly 20 rounded radial ribs, and a highly convex (bulging) profile compared to flatter scallop species like the Bay Scallop.
Collector Value
Minimal financial value ($0.10 - $1.00) due to high abundance. However, they are highly desirable for crafters and beginning collectors due to their vibrant colors and classic shape.
Condition Notes
Fair to Good. The shell is beach-worn with softened detail on the ribs and smoothed margins. The 'ears' at the hinge appear slightly damaged or eroded. It is a single valve rather than a paired set.
Interesting Facts
Unlike many other mollusks, scallops have dozens of tiny, bright blue eyes along the edge of their mantle that can detect movement and light. They are also unique among bivalves for their ability to 'swim' by rapidly snapping their shells shut to expel water.
Ecological Role
They are filter feeders that help clarify ocean water by consuming plankton and organic detritus. They serve as a vital food source for sea stars, crabs, and various species of fish.
Similar Species
Argopecten irradians (Bay Scallop) which is generally flatter and darker (gray/brown), and Nodipecten nodosus (Lion's Paw) which is much larger with heavy knobs.
Beach Finding Tips
Look along the wrack line after a storm or strong high tide. They are particularly abundant on the west coast of Florida (Sanibel Island area) and the Carolina coasts.