Seafood is any form of marine life regarded as food by humans. Seafoods include fish, molluscs (octopus and shellfish), crustaceans (shrimp and lobster), echinoderms (sea cucumber and sea urchins).
A scallop is a marine bivalve mollusk of the family Pectinidae. Scallops are a cosmopolitan family, found in all of the world's oceans. Many scallops are highly prized as a food source.
The word oyster is used as a common name for a number of distinct groups of bivalve molluscs which live in marine or brackish habitats. The valves are highly calcified.
Clawed lobsters comprise a family (Nephropidae, sometimes also Homaridae) of large marine crustaceans.