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.
Limecola balthica, commonly called the Baltic macoma, Baltic clam or Baltic tellin, is a small saltwater clam, a marine bivalve mollusk in the family Tellinidae.
A valve is each articulating part of the shell of a mollusc or another multi-shelled animal such as brachiopods and some crustaceans. Each part is known as a valve or in the case of chitons, a "plate". Members of two classes of molluscs, the Bivalvia (clams) and the Polyplacophora (chitons), have valves.
Perna perna, the brown mussel, is an economically important mussel, a bivalve mollusc belonging to the family Mytilidae. It is harvested as a food source but is also known to harbor toxins and cause damage to marine structures. It is native to the waters of Africa, Europe, and South America and was introduced in the waters of North America.
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.
Leukoma staminea, commonly known as the Pacific littleneck clam, the littleneck clam, the rock cockle, the hardshell clam, the Tomales Bay cockle, the rock clam or the ribbed carpet shell, is a species of bivalve mollusc in the family Veneridae. This species of mollusc was exploited by early humans in North America; for example, the Chumash peoples of Central California harvested these clams in Morro Bay approximately 1,000 years ago, and the distinctive shells form middens near their settlements.
Mya truncata, common name the blunt gaper or truncate softshell, is a species of edible saltwater clam, a marine bivalve mollusk in the family Myidae.
Chamelea gallina is a species of small saltwater clam, a marine bivalve in the family Veneridae, the venus clams.
Codakia orbicularis, or the tiger lucine, is a species of bivalve mollusc in the family Lucinidae. It can be found along the Atlantic coast of North America, ranging from Florida to the West Indies.
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.
Fabulina fabula, the bean-like tellin, is a species of marine bivalve mollusc in the family Tellinidae. It is found off the coasts of northwest Europe, where it lives buried in sandy sediments.
Tellina tenuis, the thin tellin, is a species of marine bivalve mollusc in the family Tellinidae. It is found off the coasts of northwest Europe and in the Mediterranean Sea, where it lives buried in sandy sediments.
Glossus is a genus of mostly extinct marine bivalve molluscs in the family Glossidae. Only the oxheart clam, G. humanus, is still extant, living in flat, muddy regions deep off the North Atlantic coastline of Europe.
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.
Dinocardium is a genus of large saltwater clams or cockles, marine bivalve molluscs in the family Cardiidae, the cockles. There is only one species in the genus, Dinocardium robustum, or the Atlantic giant cockle.
Acanthocardia tuberculata, the rough cockle, is a species of saltwater clam, a cockle, a marine bivalve mollusc in the family Cardiidae. The genus Acanthocardia is present from the Upper Oligocene to the Recent.
Acanthocardia aculeata, the spiny cockle, is a species of saltwater clams, marine bivalve molluscs in the family Cardiidae. The genus Acanthocardia is present from the Upper Oligocene to the Recent.
Venus nux is a species of saltwater clam. They are marine bivalve molluscs in the family Veneridae, sometimes known as the venus clams.
Solecurtus strigilatus, also known as the rosy razor clam, is a species of saltwater clam, a marine bivalve mollusc in the family Solecurtidae. This mollusc is a suspension feeder and can burrow with great rapidity to escape predators. It is an unusual bivalve in that its shell valves are too small to contain all the soft tissue, and the animal is unable to retreat into its shell.
Spisula subtruncata, the cut through shell, is a medium-sized marine clam, or bivalve mollusc, found in the Eastern Atlantic from Iceland to Morocco and into the Mediterranean Sea. Common and sometimes very numerous. Up to 2.5 centimetres (0.98 in) long, with a distinct triangular shape. This species of clam is found in sandy and silty bottom in the sublittoral zone, where it lives as a sediment-burrowing filter feeder.
