Clam vs. Scallop

Main Difference

The main difference between Clam and Scallop is that the Clam is a common name and Scallop is a common name for several shellfish.

• Clam

  Clam is a common name for several kinds of bivalve molluscs. The word is often applied only to those that live as infauna, spending most of their lives partially buried in the sand of the ocean floor. In particular, edible infaunal bivalves are often called clams. Clams have two shells of equal size connected by two adductor muscles and have a powerful burrowing foot. Clams in the culinary sense do not live attached to a substrate (whereas oysters and mussels do) and do not live near the bottom (whereas scallops do). In culinary usage, clams are commonly eaten marine bivalves, as in clam digging and the resulting soup, clam chowder. Many edible clams such as palourde clams are oval or triangular; however, razor clams have an elongated parallel-sided shell, suggesting an old-fashioned straight razor.

  Some clams have life cycles of only one year, while at least one may be over 500 years old. All clams have two calcareous shells or valves joined near a hinge with a flexible ligament, and all are filter feeders.

• Scallop

  Scallop () is a common name that is primarily applied to any one of numerous species of saltwater clams or marine bivalve mollusks in the taxonomic family Pectinidae, the scallops. However, the common name “scallop” is also sometimes applied to species in other closely related families within the superfamily Pectinoidea, which also includes the thorny oysters.

  Scallops are a cosmopolitan family of bivalves which are found in all of the world’s oceans, although never in freshwater. They are one of very few groups of bivalves to be primarily “free-living”, with many species capable of rapidly swimming short distances and even of migrating some distance across the ocean floor. A small minority of scallop species live cemented to rocky substrates as adults, while others attach themselves to stationary or rooted objects such as sea grass at some point in their lives by means of a filament they secrete called a byssal thread. The majority of species, however, live recumbent on sandy substrates, and when they sense the presence of a predator such as a starfish, they may attempt to escape by swimming swiftly but erratically through the water using jet propulsion created by repeatedly clapping their shells together. Scallops have a well-developed nervous system, and unlike most other bivalves all scallops have a ring of numerous simple eyes situated around the edge of their mantles.

  Many species of scallop are highly prized as a food source, and some are farmed as aquaculture. The word “scallop” is also applied to the meat of these bivalves, the adductor muscle, that is sold as seafood. The brightly coloured, symmetrical, fan-shaped shells of scallops with their radiating and often fluted ornamentation are valued by shell collectors, and have been used since ancient times as motifs in art, architecture and design.

  Owing to their widespread distribution, scallop shells are a common sight on beaches and are often brightly coloured, making them a popular object to collect among beachcombers and holidaymakers.