''Venus'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

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 Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class (biology), class of aquatic animal, aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed b ...

mollusc Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...

Etymology

The genus ''Venus'' is named after

Venus Venus is the second planet from the Sun. It is often called Earth's "twin" or "sister" planet for having almost the same size and mass, and the closest orbit to Earth's. While both are rocky planets, Venus has an atmosphere much thicker ...

, the Roman goddess of love and sexuality.

Taxonomy

However, some bivalves are still called Venus clams because they used to be in the genus ''Venus'', though they are now placed in other genera: these include the species within the genus '' Mercenaria'', and '' Pitar dione'', the Venus shell described in sexual terms by Linnaeus.

Fossil records

The genus is known from the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

to the recent periods (age range: from 136.4 Mya to now). Fossils shells have been found all over the world. About 20 extinct species are known.

The family Veneridae

The family Veneridae contains over 400 known species, many of which are attractive and popular with shell-collectors. The shells of venerids vary in shape, and include shells that are circular, triangular, and rectangular. Characteristically, Venus clams possess a porcelain-like inner shell layer, a complex tooth structure in the hinge, well-developed escutcheon and lunule, and a well-developed pallial sinus. Veneridae colonize the sandy ocean bottom, and their populations are often dense and large. The Veneroida order typically has a folded gill structure which is well developed for filtering out small food particles.

Common name

The

common name In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often con ...

s of clams in this genus often include the name Venus. A few species that still have "Venus" as part of their common name, but which are no longer in the genus ''Venus'' are: * Sunray Venus, '' Macrocallista nimbosa'' (Lightfoot) * Cross-barred Venus, '' Chione cancellata'' (Linnaeus) * Lady-in-waiting Venus, '' Chione intapurpurea'' (Conrad) * Imperial Venus, '' Lirophora latilirata'' (Conrad) * Grey pygmy Venus, '' Chione grus'' (Holmes) * Striped Venus clam, '' Chamelea gallina'' (

Linnaeus Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...

, 1758) * Elegant Venus clam, '' Pitar dione'' (

, 1758)

Species

The genus ''Venus'' contains these extant species: *'' Venus albina'' G. B. Sowerby II, 1853 *'' Venus casina''

, 1758 *'' Venus cassinaeformis'' (Yokoyama, 1926) *'' Venus chevreuxi'' Dautzenberg, 1891 *'' Venus crebrisulca'' Lamarck, 1818 *'' Venus declivis'' G. B. Sowerby II, 1853 *'' Venus lyra'' Hanley, 1845 *'' Venus nux'' Gmelin, 1791 *''Venus rosalina'' Rang, 1802: synonym of '' Venus crebrisulca'' Lamarck, 1818 *'' Venus subrosalina'' Tomlin, 1923 *'' Venus thomassini'' Fischer-Piette & Vukadinovic, 1977 *'' Venus verdensis'' Dautzenberg & H. Fischer, 1906 *'' Venus verrucosa''

, 1758