Yellow Cockle, Prickly Cockle
Phylum: Mollusca, Class: Bivalvia, Order: Cardiida, Family: Cardiidae, Genus: Divalinga, Species: Divalinga quadrisulcata · Cardiidae (Cockle family) · Bivalve (Single Valve); shape is sub-circular and inflated.
Species
Divalinga quadrisulcata
Shell Type
Bivalve (Single Valve); shape is sub-circular and inflated.
Family
Cardiidae (Cockle family)
Size
Approximately 0.75 inches (19mm). Typical adults range from 0.5 to 1.5 inches; this is a standard medium-sized specimen.
Color & Pattern
Creamy white to light yellowish-tan base. It features distinct reddish-brown or orange spots and speckles concentrated along the radial ribs. The interior is generally glossy white with a hint of yellow near the umbo.
Rarity
Common; frequently found on North Carolina beaches, especially after storms or high tides.
Habitat
Marine; found in shallow subtidal waters and intertidal zones. Prefers sandy substrates where it can burrow just below the surface.
Geographic Range
Western Atlantic: North Carolina to Florida, the Gulf of Mexico, and the West Indies to Brazil. This specimen from Holden Beach is at the northern end of its core range.
Description
A sturdy, heart-shaped bivalve with roughly 30 to 40 radiating ribs. The ribs are decorated with small, scale-like projections or 'prickles' that give it a rough texture. The shell is strongly inflated (puffy) and possesses a well-defined hinge.
Key Features
Distinctive 'prickly' radial ribs; yellowish hue concentrated near the beak (umbo); prominent reddish-brown spots on the ribs; crenulated (toothed) inner margins.
Collector Value
Low to modest ($1-$5 range). It is highly desirable for beginners and craft-makers due to its beautiful color and symmetry, but very common in the trade.
Condition Notes
Good condition. The exterior sculpture is well-preserved, though some minor beach-wear is visible on the scales. The color spots remain vibrant, suggesting it was not exposed to the sun for an extended period.
Interesting Facts
Cockles are known for their strong muscular 'foot,' which they use not just for burrowing, but also to 'jump' across the seafloor to escape predators like sea stars.
Ecological Role
Suspension feeder that filters plankton and organic detritus from the water column. They serve as a vital food source for shorebirds, crabs, and bottom-dwelling fish.
Similar Species
Trachycardium muricatum (Yellow Cockle) has more numerous ribs and a more elongated shape. Dinocardium robustum (Giant Atlantic Cockle) is much larger and lack the sharp prickly scales.
Beach Finding Tips
Look in the 'shell hash' lines at low tide at Holden Beach. They are most often found as single valves; finding a matched pair (hinged together) is a much rarer prize.
Notes
Holden Beach, NC