Mollusks

Mollusks come in many shapes and sizes. They include univalves, which have single, often spiral shells, bivalves like oysters with a double shell, and cephalopods such as squid and octopus. Whether they are being prepared to eat raw or cooked, mollusks in the shell must be alive. Univalves should retreat into their shell when poked and bivalve shells should be tightly closed (although scallops and soft-shell clams never close completely, even when alive). In the shell or out, all mollusks should have a sweet sea-salt smell. They are often sold according to size and the grading for sought-after kinds such as oysters is complicated.