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.
The maxima clam, also known as the small giant clam, is a species of bivalve mollusc found throughout the Indo-Pacific region.
Anomalodesmata is an superorder of saltwater clams, marine bivalve molluscs. This grouping was formerly recognised as a taxonomic subclass. It is called a superorder in the current World Register of Marine Species, despite having no orders, to parallel it with sister taxon Imparidentia, which does have orders.
Lyonsiidae is a family of small saltwater clams, marine bivalve molluscs in the order Anomalodesmata.
Pholadomyidae is a family of saltwater clams, marine bivalve molluscs in the order Anomalodesmata.
Poromyidae is a family of saltwater clams, marine bivalve molluscs in the order Anomalodesmata. The genus Dilemma, described in 2008, is remarkable for being a predator of copepods, which is very unusual for a sessile mollusc.
Mollusca is the second-largest phylum of invertebrate animals, after Arthropoda; members are known as molluscs or mollusks. Around 76,000 extant species of molluscs are recognized. The number of fossil species is estimated between 60,000 and 100,000 additional species. The proportion of undescribed species is very high. Many taxa remain poorly studied.
Dilemma is a genus of marine bivalves of the family Poromyidae. The genus is remarkable for encompassing predators of isopods and ostracods, unusual for sessile molluscs. One species is known from the western Atlantic Ocean and three from across the Pacific. Specimens have been found at depths between 229–961 m (751–3,153 ft). The name of the genus refers to the dilemma that the author of the new genus faced while diagnosing it.
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.
The Festivus is a publication about malacology and conchology published by the San Diego Shell Club in San Diego, California. The Festivus started in 1970 as a shell club newsletter edited by Blanche Brewer. In 1976 Carole Hertz became the editor, and gradually The Festivus became more scientifically respectable, and was transformed into a peer-reviewed scientific journal. From 1985 up until 2014, issues of The Festivus contained scientific papers on mollusks, and each paper was peer-reviewed by a professional malacologist. Eleven issues were published annually: one issue per month, except for the month of December. Carole Hertz was editor for 37 years.
Pholadomya is a genus of saltwater clams, marine bivalve molluscs in the family Pholadomyidae.
Verticordia is a genus of marine bivalve molluscs in the family Verticordiidae. >
Cetoconcha is the only extant genus of saltwater clams in the family Cetoconchidae.
Parilimyidae is a family of bivalves belonging to the superorder Anomalodesmata.
Saccella is a genus of bivalves belonging to the family Nuculanidae.
Trigonulina d'Orbigny, 1853 is a genus of small carnivorous bivalves in the family Verticordiidae. It was first named by Alcide d'Orbigny with the type taxon T. ornata in 1853, though T. novemcostata was named first originally as Hippagus novemcostatus in 1850 which is now unaccepted. Trigonulina shells are known to be extremely small, ranging from about 1-3.6 millimeters long. They live at depths of 18-850 meters below the ocean's surface and burrow under sand to feed on microscopic crustaceans using adapted inhalant siphons. T. ornata lives in the western Atlantic Ocean while T. novemcostata is native to the South China Sea.
Trigonulina ornata, commonly known as the "ornate verticord", is a carnivorous bivalve in the family Verticordiidae. It is native to coastal waters throughout the western Atlantic Ocean at depths of 18-850 meters below the surface. It has 8-11 prominent ribs on its surface and can be a maximum of 5.6 millimeters in size, though on average ranges from 1-3.6 millimeters.
Spheniopsis is a genus of bivalves in the family Spheniopsidae which currently consists of five species. Species such as S. brasiliensis live in the western Atlantic Ocean off the coast of Brazil at depths of 17–148 meters. Bivalves in this genus are part of the order Anomalodesmata, also known as septibranchs, which are carnivorous clams.
Samacar is a genus of bivalves in the family Arcidae which has three species. It was first described by malacologist Tom Iredale in 1936 with the type taxon S. strabo found in Dundas, New South Wales, Australia. Shells are about 11 millimeters long. This genus spans throughout the Tasman Sea and Pacific Ocean reaching as far north as Japan
