Oysters are the most prized of the bivalves. They are the sea’s tenderest morsels, the marine equivalent of penned veal or the fattened chicken, which just sit and eat. Their shell-closing adductor amounts to just a tenth of the body weight, the thin, delicate sheets of all-enclosing mantle and gills account for more than half, and the visceral mass for a third. The oyster is a special delicacy when cut from the shell and eaten raw. It’s big enough to make a generous morsel, has a full, complex flavor and suggestively slippery moistness; and its delicacy is a striking contrast to the encrusted, rocky shell.