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. Bivalves as a group have no head and they lack some usual molluscan organs like the radula and the odontophore. They include 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. The shipworms bore into wood, clay, or stone and live inside these substances.
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.
A adductor muscle is any muscle that causes adduction. It may refer to:
Laternulidae, common name lantern clams, is a family of saltwater clams, marine bivalve molluscs in the order Anomalodesmata.
The grooved carpet shell, or Palourde clam, Ruditapes decussatus, or Venerupis decussatus, is a clam or bivalve mollusc in the family Veneridae. It is distributed worldwide and due to its ecological and economic interest has been proposed as a bioindicator.
Modiolus modiolus, common name northern horsemussel, is a species of marine bivalve mollusk in the family Mytilidae.
Anodontia alba, or the buttercup lucine, is a species of bivalve mollusc in the family Lucinidae. It can be found along the Atlantic coast of North America, its range extending from North Carolina in the United States to the West Indies.
Anodontia philippiana, or the chalky buttercup, is a species of bivalve mollusc in the family Lucinidae. It can be found burrowing in soft substrate in shallow waters along the Atlantic coast of North America, its range extending from North Carolina in the United States to the West Indies and Bermuda.
Ensis ensis, or the sword razor, is a razor clam, a marine bivalve mollusc in the family Pharidae. It lives buried in the sand and is found off the coasts of northwest Europe.
Venerupis decussata is a marine bivalve mollusc in the family Veneridae, commonly known as the cross-cut carpet shell.
Thracia convexa is a bivalve mollusc in the family Thraciidae.
Fordillidae is an extinct family of early bivalves and one of two families in the extinct superfamily Fordilloidea. The family is known from fossils of early to middle Cambrian age found in North America, Greenland, Europe, the Middle East, Asia, and Australia. The family currently contains two genera, Fordilla and Pojetaia, each with up to three described species. Due to the size and age of the fossil specimens, Fordillidae species are included as part of the Turkish Small shelly fauna.
Fordilloidea is an extinct superfamily of early bivalves containing two described families, Fordillidae and Camyidae and the only superfamily in the order Fordillida. The superfamily is known from fossils of early to middle Cambrian age found in North America, Greenland, Europe, the Middle East, Asia, and Australia. Fordillidae currently contains two genera, Fordilla and Pojetaia each with up to three described species while Camyidae only contains a single genus Camya with one described species, Camya asy. Due to the size and age of the fossil specimens, Fordillidae species are included as part of the Turkish Small shelly fauna.
Cucullaea labiata is a species of saltwater clam or ark shell, a marine bivalve mollusk in the family Cucullaeidae.
Laternula elliptica is a species of saltwater clam, a marine bivalve mollusc in the family Laternulidae, the lantern shells. It is the largest bivalve found under the surface of the seabed in the Southern Ocean.
Venerupis corrugata, the pullet carpet shell, is a species of bivalve mollusc in the family Veneridae. It is found buried in the sediment on the sea bed in shallow parts of the eastern Atlantic Ocean. It is harvested for human consumption in Spain and other parts of Western Europe.
A hinge ligament is a crucial part of the anatomical structure of a bivalve shell, i.e. the shell of a bivalve mollusk. The shell of a bivalve has two valves and these are joined together by the ligament at the dorsal edge of the shell. The ligament is made of a strong, flexible and elastic, fibrous, proteinaceous material which is usually pale brown, dark brown or black in color.
The pallial sinus is an indentation or inward bending in the pallial line on the interior of a bivalve mollusk shell's valves that corresponds to the position of the siphons in those types of clams which have siphons. The position of the pallial sinus is often clearly visible as a shiny line on the inside of the bivalve shell.
The adductor muscles are the main muscular system in bivalve mollusks, i.e. in clams, scallops, mussels, oysters, etc. In many parts of the world, when people eat scallops, the adductor muscles are the only part of the soft parts of the animal which are eaten. Adductor muscles leave noticeable scars or marks on the interior of the shell's valves. Those marks are often used by scientists who are in the process of identifying empty shells to determine their correct taxonomic placement.
