Atlantic Calico Scallop (also known as Calico Scallop)
Phylum: Mollusca, Class: Bivalvia, Order: Pectinida, Family: Pectinidae, Genus: Argopecten, Species: Argopecten gibbus · Pectinidae (Scallop family) · Bivalve (two-shelled). It is a whole single valve shell with a fan-shaped morphology.
Species
Argopecten gibbus
Shell Type
Bivalve (two-shelled). It is a whole single valve shell with a fan-shaped morphology.
Family
Pectinidae (Scallop family)
Size
Approximately 1.5 to 2 inches in width, which is average for this species. Adult Atlantic Calico Scallops typically range from 1.5 to 2.5 inches.
Color & Pattern
The exterior exhibits a warm peach to orange-yellow base color with mottled whitish and darker orange or reddish speckles creating a calico-like pattern. The coloration is completely natural and well-preserved, featuring distinct radial ribs.
Rarity
Common. This species is regularly found washed ashore on beaches within its geographic range, particularly along the southeastern United States and the Gulf coast of Florida.
Habitat
Found in shallow marine waters, typically ranging from the intertidal zone down to depths of about 150 feet. They prefer sandy or shell-gravel bottoms, often among seagrass beds where they can rest and move freely.
Geographic Range
Western Atlantic Ocean, extending from Maryland down through Florida, the Gulf of Mexico, the Bahamas, and the Caribbean Sea.
Description
An attractive, roughly symmetrical fan-shaped bivalve with prominent, rounded radial ribs radiating outward from the umbo (beak). The hinge area features characteristic unequal auricles (ears) typical of scallops. The surface has a fine, granular texture with crisp margins along the ventral edge.
Key Features
Rounded fan shape, approximately 18 to 22 prominent radial ribs, unequal 'ears' or wings at the hinge line, and a mottled reddish, orange, or brownish calico color pattern over a pale background.
Collector Value
Low to moderate commercial value. While very popular among casual beachcombers and used extensively in shell crafts, specimens are common and typically sold inexpensively in bulk, though choice brightly colored single specimens are appreciated in beginner collections.
Condition Notes
Good to Fine condition. The valve is intact with no major chips or structural breaks. The ribs are sharp, and the natural color is vibrant with minimal fading or surface erosion.
Interesting Facts
Unlike many bivalves that burrow or cement themselves to surfaces, Calico Scallops are capable of swimming short distances by rapidly clapping their valves together to expel water, allowing them to escape predators like sea stars.
Ecological Role
Calico scallops serve as an important food source for numerous marine predators, including fish, crabs, sea turtles, and rays. As filter feeders, they help clear particulate matter from the water column, contributing to coastal water quality.
Similar Species
Atlantic Bay Scallop (Argopecten irradians), which tends to be slightly larger with flatter ribs and is usually found in shallower estuarine seagrass beds rather than deeper offshore waters.
Beach Finding Tips
Look along high-tide wrack lines on sandy ocean-facing beaches, especially after storms or heavy onshore winds in Florida and the Carolinas. Early morning just after the turn of the tide is ideal.