Ari Daniel Shapiro is joined for this episode of One Species at a Time by serious beachcombers along the high-tide line of Sanibel Island, Florida. These “shellers” come in search of beautiful sea shells, sometimes no bigger than a grain of rice, that are the remains of marine snails, bivalves, and other mollusks. Along the beach and at the island's Bailey-Matthews Shell Museum, we learn why Sanibel’s shores are so rich in molluscan treasure, and how shelling has captured the imaginations of scientists and enthusiasts alike.