Cockle Shell (Heart Cockle / Common Edible Cockle)
Phylum: Mollusca, Class: Bivalvia, Order: Cardiida, Family: Cardiidae, Genus: Cerastoderma, Species: Cerastoderma edule · Cardiidae (Cockle family) · Bivalve, whole shell valve, fan/heart-shaped morphology
Species
Cerastoderma edule
Shell Type
Bivalve, whole shell valve, fan/heart-shaped morphology
Family
Cardiidae (Cockle family)
Size
Approximately 1 to 1.5 inches in width, which is typical for an adult specimen of this species. Adults generally range between 1 and 2 inches.
Color & Pattern
Muted brownish-grey to cream exterior with natural weathering and faint concentric growth lines intersecting strong radial ribs. The colors appear natural and somewhat beach-worn, lacking vibrant contrasting blotches.
Rarity
Very Common, frequently encountered washed ashore along European and North Atlantic coastlines.
Habitat
Shallow marine and brackish waters, typically found burrowed just beneath the surface of intertidal mudflats and fine sandy sediments.
Geographic Range
Northeastern Atlantic Ocean, extending from the coast of Norway and the Barents Sea down to West Africa, including the Mediterranean and Baltic Seas.
Description
A sturdy, globular bivalve shell featuring distinct, prominent radial ribs that radiate from the umbo to the margin, crossed by fine concentric growth lines giving it a textured, grid-like appearance. The margin is strongly crenulated to match the external ribs.
Key Features
Symmetrical heart-shaped profile when viewed from the side, prominent radial ribs numbering around 22 to 28, and a strongly toothed or crenulated inner margin.
Collector Value
Low to Moderate. While immensely popular for casual beachcombing and crafts, they hold little monetary value for advanced conchology collectors due to their high abundance.
Condition Notes
Fair to Good condition; shows signs of natural beach weathering, dulling of the original color, and minor wear along the margins, but structurally intact.
Interesting Facts
Cockles are capable of leaping using their muscular foot to escape predators like starfish. They are also commercially harvested for human consumption across Europe.
Ecological Role
Important benthic filter feeders that help clear particulate matter from the water column. They serve as a primary food source for numerous shorebirds, fish, and crabs.
Similar Species
Spiny Cockle (Acanthocardia aculeata), which possesses much sharper, prominent spines along the ribs compared to the smoother ribs of Cerastoderma edule.
Beach Finding Tips
Look along intertidal sandy or muddy beaches at low tide. Searching near tidal pools or exposed sandbars often yields both single valves and matching pairs.