Trachycardium muricatum Linnaeus, 1758
Cheery-colored Yellow Cockles are about two inches long at adult size. (The length is measured across the shell, away from the beak area.) When you look down at the mollusk, its shape is almost circular, with two valves of equal size. The edges of the valves are serrated, and they interlock. The surface of each valve is adorned with 20-40 radiating ribs. Those near the beak or umbonal area are smooth; those farther out from the beak area have small spines. The shell is yellowish-white, perhaps with pale brownish-red markings. The interior surface of the bivalve is delicate yellow or white.
Living Cockles are very active animals. A Cockle can jump several inches by pushing off with its powerful foot, a muscular extension of its body.
Edible Cockles (Cerastoderma edule) are used as food in Europe, where people gather them on the beaches. Cockles are sometimes called “heart clams.” The bivalve is heart-shaped when viewed from the end.
Most children learn of cockle shells early in life upon hearing the nursery rhyme in which “silver bells and cockleshells and pretty maids in a row” are mentioned (see notes below).
Yellow Cockles may be found in moderately shallow water (30-80 feet) from the coast of North Carolina to the West Indies and Brazil. These are fairly common, but lovely, beach finds.