Yellow Cockle (also known as the Isocardia Heart Cockle or Atlantic Egg Cockle)
Phylum: Mollusca, Class: Bivalvia, Order: Cardiida, Family: Cardiidae, Genus: Laevicardium, Species: Laevicardium laevigatum · Cardiidae (Cockle family) · Bivalve (two-shelled), whole valve, rounded/heart-shaped fan profile
Species
Laevicardium laevigatum
Shell Type
Bivalve (two-shelled), whole valve, rounded/heart-shaped fan profile
Family
Cardiidae (Cockle family)
Size
Approximately 1.5 inches, which is within the normal adult size range of 1 to 2.5 inches for this species.
Color & Pattern
Pale off-white to creamy yellow base color with very subtle, faint brownish or yellowish radial banding. The coloration is somewhat sun-bleached, presenting a uniform matte cream finish across the exterior.
Rarity
Common, frequently discovered intact by beachcombers along sandy shorelines of Florida and the Caribbean.
Habitat
Found in shallow marine waters, typically living buried just beneath the surface in clean sandy bottoms of seagrass beds and sandflats, from the intertidal zone down to about 50 meters depth.
Geographic Range
Western Atlantic Ocean, ranging from North Carolina through the Caribbean, the Gulf of Mexico, and down to Brazil.
Description
A delightful, symmetrical bivalve featuring numerous fine, regular radial ribs extending from the prominent umbo down to the crenulated margin. The shell has a smooth, solid feel with a rounded, inflated profile that hints at its heart-shaped cross-section when both valves are joined.
Key Features
Distinguished by its symmetrical, inflated shape, the prominent central umbo, and dozens of fine, closely spaced radial ribs rather than heavy or coarse ridges.
Collector Value
Low to moderate value. While widely collected and popular among amateur beachcombers, common specimens hold little monetary value, usually selling for just a few cents to a dollar.
Condition Notes
Good condition. It is a single intact valve with minor surface weathering and slight fading of the original bright yellow coloration due to sun exposure, but the margins and ribs are well-preserved.
Interesting Facts
Cockles are capable of escaping predators by using their strong, muscular foot to leap or vault away across the sand, an acrobatic movement quite unusual for most bivalves.
Ecological Role
Serves an important role in benthic filter-feeding, helping to clear water columns, while acting as a vital food source for bottom-feeding fish, rays, and carnivorous sea snails.
Similar Species
Loggerhead Key Cockle (Dinocardium robustum), which is significantly larger and has heavier, more pronounced ribs and distinct blotches.
Beach Finding Tips
Look along high-tide wrack lines on fine white sand beaches after stormy weather or strong offshore winds, particularly in the morning hours.