Calico Scallop (also known as the Speckled Scallop)
Phylum: Mollusca, Class: Bivalvia, Order: Pectinida, Family: Pectinidae, Genus: Argopecten, Species: A. gibbus · Pectinidae (Scallop family) · Bivalve (two-shelled); this specimen is a single valve (half-shell) with a fan-like shape.
Species
Argopecten gibbus
Shell Type
Bivalve (two-shelled); this specimen is a single valve (half-shell) with a fan-like shape.
Family
Pectinidae (Scallop family)
Size
Approximately 0.5 - 0.75 inches (12-19mm). This is a juvenile specimen; adults typically reach 1.5 to 3 inches.
Color & Pattern
Creamy white base with mottled patches of orange-brown and tan. The patterning shows classic 'calico' spotting. The interior is likely white or pale yellow. Colors are slightly worn but naturally vibrant.
Rarity
Very Common. These are among the most frequently found shells on the beaches of Cancun and the Southeastern United States.
Habitat
Found in marine environments, typically inhabiting sandy or shelly substrates in open water at depths of 10 to 400 feet, often in high-salinity areas.
Geographic Range
Western Atlantic from Delaware to Brazil, very common in the Gulf of Mexico, Caribbean Sea, and around the Yucatan Peninsula (Cancun area).
Description
An attractive, fan-shaped bivalve with roughly 17 to 23 radiating ribs. The ribs are rounded and prominent. The shell features 'ears' or auricles at the hinge, which are roughly equal in size. The texture is slightly rough due to growth lines crossing the ribs.
Key Features
Rounded ribs, nearly symmetrical auricles (ears), and the distinctive mottled calico color pattern. Unlike the Bay Scallop, the Calico Scallop is more inflated (deeper/rounder).
Collector Value
Low monetary value ($0.25 - $1.00) due to high abundance, but highly desired by crafters and beachcombers for their beautiful, varied patterns. Larger, paired valves (both halves attached) are more prized.
Condition Notes
Good condition. It is a beach-worn single valve. The edges (crenulations) appear intact. There is some minor surface erosion from wave action, giving it a matte finish. Collectibility grade: Good.
Interesting Facts
Unlike most mollusks, scallops have dozens of tiny, bright blue eyes along the edge of their mantle to detect motion. They are also 'swimmers,' using jet propulsion by clapping their valves together to escape predators like sea stars.
Ecological Role
They are filter feeders, helping to clear the water of plankton and organic detritus. They serve as a vital food source for crabs, octopuses, and various fish. The species supports a significant commercial fishery in the US.
Similar Species
Argopecten irradians (Bay Scallop) - which usually has darker grey/brown coloring and is less 'inflated' or round in cross-section.
Beach Finding Tips
Look along the high-tide line after a storm or strong offshore winds. In Cancun, they are easily found by sifting through the 'wrack line' (seaweed and debris) on the sand.
Notes
Cancun