Bivalvia, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bivalves have no head and they lack some usual molluscan organs, like the radula and the odontophore. The class includes the clams, oysters, cockles, mussels, scallops, and numerous other families that live in saltwater, as well as a number of families that live in freshwater. The majority are filter feeders. The gills have evolved into ctenidia, specialised organs for feeding and breathing. Most bivalves bury themselves in sediment, where they are relatively safe from predation. Others lie on the sea floor or attach themselves to rocks or other hard surfaces. Some bivalves, such as the scallops and file shells, can swim. Shipworms bore into wood, clay, or stone and live inside these substances.
Scallop is a common name that encompasses various species of 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.
Argopecten gibbus, the Atlantic calico scallop, is a species of medium-sized edible marine bivalve mollusk in the family Pectinidae, the scallops.
Atrina fragilis, the fan mussel, is a species of large saltwater clam, a marine bivalve mollusc in the family Pinnidae, the pen shells.
The Pinnidae are a taxonomic family of large saltwater clams sometimes known as pen shells. They are marine bivalve molluscs in the order Pteriida.
A bivalve shell is part of the body, the exoskeleton or shell, of a bivalve mollusk. In life, the shell of this class of mollusks is composed of two hinged parts or valves. Bivalves are very common in essentially all aquatic locales, including saltwater, brackish water, and freshwater. The shells of bivalves commonly wash up on beaches and along the edges of lakes, rivers, and streams. Bivalves by definition possess two shells or valves, a "right valve" and a "left valve", that are joined by a ligament. The two valves usually articulate with one another using structures known as "teeth" which are situated along the hinge line. In many bivalve shells, the two valves are symmetrical along the hinge line—when truly symmetrical, such an animal is said to be equivalved; if the valves vary from each other in size or shape, inequivalved. If symmetrical front-to-back, the valves are said to be equilateral, and are otherwise considered inequilateral.
The grooved carpet shell, or Palourde clam, Ruditapes decussatus, or Venerupis decussatus, is a clam in the family Veneridae. It is distributed worldwide and is highly prized due to its ecological and economic interest. It has been proposed as a bioindicator.
Pecten maximus, common names the great scallop, king scallop, St James shell or escallop, is a northeast Atlantic species of scallop, an edible saltwater clam, a marine bivalve mollusc in the family Pectinidae. This is the type species of the genus. This species may be conspecific with Pecten jacobaeus, the pilgrim's scallop, which has a much more restricted distribution.
Modiolus modiolus, common name northern horsemussel, is a species of marine bivalve mollusk in the family Mytilidae.
Amygdalum papyrium, common name the Atlantic paper mussel, is a species of marine bivalve mollusc in the family Mytilidae, the true mussels. This species occurs along the Atlantic coast of North America, from Maryland to Florida, as well as in the Gulf of Mexico, from Texas to Mexico.
Pteria colymbus, the Atlantic winged oyster, is a species of bivalve mollusc in the family Pteriidae. It can be found along the Atlantic coast of North America, ranging from North Carolina to Bermuda and Brazil.
Pododesmus patelliformis, the ribbed saddle-oyster, is a species of bivalve mollusc in the family Anomiidae. It is found in the north east Atlantic Ocean.
Tellimya ferruginosa is a species of small marine bivalve mollusc in the family Lasaeidae. It is found on the eastern side of the Atlantic Ocean.
The Antarctic scallop is a species of bivalve mollusc in the large family of scallops, the Pectinidae. It was thought to be the only species in the genus Adamussium until an extinct Pliocene species was described in 2016. Its exact relationship to other members of the Pectinidae is unclear. It is found in the ice-cold seas surrounding Antarctica, sometimes at great depths.
Crassadoma is a genus of rock scallops, marine bivalve molluscs in the family Pectinidae. It is monotypic, the only species being Crassadoma gigantea, the rock scallop, giant rock scallop or purple-hinge rock scallop. Although the small juveniles are free-swimming, they soon become sessile, and are cemented to the substrate. These scallops occur in the eastern Pacific Ocean.
Mimachlamys asperrima, common name the austral scallop, doughboy, doughboy scallop, fan shell, or prickly scallop, is a species of scallop, a marine bivalve mollusc in the family Pectinidae, the scallops.
Swiftopecten swifti, common name Swift's scallop, is a species of bivalve mollusc in the family Pectinidae. It occurs in the northern Pacific Ocean.
Mimachlamys is a genus of scallops, marine bivalve molluscs in the taxonomic family Pectinidae. There are at least 11 living species, including the glory scallop Mimachlamys gloriosa, and the Mimachlamys asperrima.
Brachidontes pharaonis is a species of mussel from the family Mytilidae. It is native to the Indian Ocean and the Red Sea, and has colonised the Mediterranean Sea where it is regarded as an invasive species.
Lasaea rubra is a species of small marine bivalve mollusc in the family Lasaeidae. It is found on the eastern side of the Atlantic Ocean. This species was first described in 1803 by the English naturalist George Montagu who gave it the name Cardium rubrum. It was later transferred to the genus Lasaea, making it Lasaea rubra.
