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.
Clam shrimp are a group of bivalved branchiopod crustaceans that resemble the unrelated bivalved molluscs. They are extant and also known from the fossil record, from at least the Devonian period and perhaps before. They were originally classified in the former order Conchostraca, which later proved to be paraphyletic, due to the fact that water fleas are nested within clam shrimps. Clam shrimp are now divided into three orders, Cyclestherida, Laevicaudata, and Spinicaudata, in addition to the fossil family Leaiidae.
Tridacna gigas, the giant clam, is the most well-known species of the giant clam genus Tridacna. Giant clams are the largest living bivalve mollusks. Several other species of "giant clams" in the genus Tridacna, are often misidentified as Tridacna gigas.
Venus is a genus of small to large saltwater clams in the family Veneridae, which is sometimes known as the Venus clams and their relatives. These are marine bivalve molluscs.
Olive snails, also known as olive shells and olives, scientific name Olividae, are a taxonomic family of medium to large predatory sea snails with smooth, shiny, elongated oval-shaped shells.
Tridacna crocea, the boring clam, crocus clam, crocea clam or saffron-coloured clam, is a species of bivalve in the family Cardiidae. It is native to the Indo-Pacific region. It is occasionally found in the aquarium trade where it is often simply referred to as crocea.
Galeommatidae is a family of small and very small saltwater clams, marine bivalve molluscs in the order Galeommatida.
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.
Calyptogena magnifica is a species of giant white clam found clustered around hydrothermal vents at abyssal depths in the Pacific 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.
Pteria penguin, commonly known as the penguin's wing oyster, is a species of marine bivalve mollusk in the family Pteriidae, the pearl oysters. It is native to the western and central Indo-Pacific region and is used for the production of cultured pearls. The generic name comes from Greek πτερον (pteron) meaning wing.
Neotrigonia margaritacea, common name the pearly brooch-shell, is a species of saltwater clam, a marine bivalve mollusc in the family Trigoniidae. This species is known from sandy substrates in shallow seas in southeastern and southwestern Australia. This species was the first member of the family to be discovered alive; previous to its discovery, trigoniids were only known from fossils.
Grimpoteuthis bathynectes is a deepwater species of Grimpoteuthis (Dumbo) octopus first described in 1990. It is known from 13 specimens.
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.
Thyonicola dogieli is a parasitic species of gastropod mollusc in the family Eulimidae. It parasitises sea cucumbers in the northeastern Pacific Ocean.
Polydora glycymerica is a species of annelid worm in the family Spionidae, native to the northwestern Pacific Ocean, where it lives commensally in association with a bivalve mollusc, usually Glycymeris yessoensis but occasionally with another species of clam. The worm intercepts food particles being drawn into the mollusc by its feeding current.
Idas simpsoni, previously known as Adipicola simpsoni, is a species of saltwater clam, a marine bivalve mollusc in the family Mytilidae, the mussels. It is a deepwater species and is only found attached to the bones of dead whales.
Pharus legumen, is a species of bivalve mollusc commonly found burrowed in the sand on lower shores and in the shallow sublittoral.
Kuphus polythalamius is a species of shipworm, a marine bivalve mollusc in the family Teredinidae.
Tridacna squamosina is a species of the Tridacna genus, the giant clams. These animals are bivalve mollusks belonging to the family Cardiidae identified by Sturany 1899.
