This set of Heart Cockles is most appropriate for February Shell of the Month as we honor St. Valentine. Corculum cardissa, Linné 1758, is a most unusual bivalve. It’s anatomy is rotated ninety degrees. The valves open down the center rather than at the sides.
Corculum live in sandy bottom where sea grasses grow, often in dense colonies. They attach themselves to the sand with a byssus thread. They are most prevalent in the offshore waters of Cebu, Philippines, but range north to Malaysia.
Splitters divide this shell into multiple species. “Shells of the Philippines” by Springsteen and Leobrera site 5 different specie but admit they might be “morphophenotypes of a single taxon.”
Heart cockles are attractive shells, coming in a variety of delicate pastels, often solid, sometimes speckled, with pale yellow to white being most common with orange, pink and lavender harder to come by. They are seeming endless in variety of heart shapes. Average size is about 40mm but they come smaller and rarely from 55 to 65mm. The heart shells in this set range in size from about 35 to 55mm. The top left and top right are often sold as Corculum impressum, Lightfoot 1786. All came from off the coast of Cebu and were collected in 2010.