Cockle Shell (Heart Cockle / Common Cockle)
Phylum: Mollusca, Class: Bivalvia, Order: Cardiida, Family: Cardiidae, Genus: Acanthocardia, Species: A. tuberculata · Cardiidae (Cockle family) · Bivalve (two-shelled), single valves shown, fan/heart-shaped
Species
Acanthocardia tuberculata
Shell Type
Bivalve (two-shelled), single valves shown, fan/heart-shaped
Family
Cardiidae (Cockle family)
Size
Approximately 1.5 to 2 inches in width, which is typical for adult specimens of this species which generally range between 1.5 and 3 inches.
Color & Pattern
Uniform chalky white, heavily sun-bleached with the natural outer coloration completely faded. The interior, though not fully visible, matches the exterior bleached white appearance.
Rarity
Common
Habitat
Found buried shallowly in clean sand, muddy sand, or fine gravel in the intertidal and shallow subtidal zones down to about 30 meters.
Geographic Range
Eastern Atlantic Ocean, extending from the British Isles down along the coast of Europe, the Mediterranean Sea, and into Northwest Africa.
Description
A classic heart-shaped bivalve featuring strong, prominent radial ribs radiating from the umbo to the margin. The surface displays distinct interlocking ridges and fine transverse growth lines, giving the exterior a robust, textured appearance typical of the Cardiidae family.
Key Features
Symmetrical heart-shaped profile when viewed from the side, strong and prominent radial ribs (typically around 20-24), and a strongly toothed inner margin.
Collector Value
Low to moderate commercial value. While widely collected by beachcombers, pristine colored specimens are valued more than these common, sun-bleached beach finds.
Condition Notes
Fair to Good condition. The shells are intact single valves with well-preserved structural ribs, but they are completely sun-bleached white with a total loss of natural pigmentation.
Interesting Facts
Cockles are capable of leaping by using their muscular, sickle-shaped foot to push themselves away from predators like starfish and carnivorous snails.
Ecological Role
Important benthic filter feeders that help clear particulate matter from the water column, serving as a primary food source for numerous fish, shorebirds, and crabs.
Similar Species
Other members of the Cardiidae family such as Cerastoderma edule (Common Cockle), which typically has more numerous and smoother ribs.
Beach Finding Tips
Look along sandy beaches at low tide, especially after a storm or rough surf conditions when dislodged shells are washed ashore.