Crabs , crayfish , lobster and shrimp are crustaceans.
Mollusks have soft bodies with no spinal column and are covered by a shell in one or more pieces.
Examples are abalone , clams , mussels , oysters , scallops , snails , octopus and squid . Imitation seafood products such as imitation crab legs and lobster bites often are less expensive than shellfish, but provide a similar taste and texture in recipes. Imitation seafood is made from pollock , a mild white-fleshed fish. To flavor it, real shellfish, a shellfish extract or artificial shellfish flavoring is added, along with stabilizers. Selecting Shellfish Check out the selection of shellfish at your local supermarket or seafood market for both fresh and frozen shellfish.