''Mercenaria'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of edible saltwater clams,

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

bivalve 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, bival ...

mollusc Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...

s in the family

Veneridae The Veneridae or venerids, common name: Venus clams, are a very large family of minute to large, saltwater clams, marine bivalve molluscs. Over 500 living species of venerid bivalves are known, most of which are edible, and many of which are e ...

, the Venus clams. The genus ''Mercenaria'' includes the quahogs, consisting of ''Mercenaria mercenaria'', the

northern quahog The hard clam (''Mercenaria mercenaria''), also known as the round clam, hard-shell (or hard-shelled) clam, or the quahog, is an edible marine bivalve mollusk that is native to the eastern shores of North America and Central America from Prince E ...

hard clam The hard clam (''Mercenaria mercenaria''), also known as the round clam, hard-shell (or hard-shelled) clam, or the quahog, is an edible marine bivalve mollusk that is native to the eastern shores of North America and Central America from Prince ...

, and ''M. campechiensis'', the southern quahog. These two species commonly hybridise where their ranges overlap. Mercenaria mercenaria is further subdivided in the marketplace and thence in the kitchen by size: the largest being the quahog or chowder clam, then smaller cherrystones, and smallest littlenecks; some markets also differentiate top necks which are intermediate in size between cherrystones and littlenecks. The smaller clams are eaten raw throughout New England, New York, and New Jersey; the larger clams are more suited for cooking. Other species within the genus include the

venus clam The Veneridae or venerids, common name: Venus clams, are a very large family of minute to large, saltwater clams, marine bivalve molluscs. Over 500 living species of venerid bivalves are known, most of which are edible, and many of which are ex ...

''M. stimpsoni'' found in north Pacific waters. All these species were formerly placed in the related genus ''

Venus Venus is the second planet from the Sun. It is sometimes called Earth's "sister" or "twin" planet as it is almost as large and has a similar composition. As an interior planet to Earth, Venus (like Mercury) appears in Earth's sky never fa ...

''.

Species

The

World Register of Marine Species The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive list of names of marine organisms. Content The content of the registry is edited and maintained by scientific specialist ...

accepts the following extant species as valid: * '' Mercenaria campechiensis'' (Gmelin, 1791) – Southern quahog * ''

Mercenaria mercenaria The hard clam (''Mercenaria mercenaria''), also known as the round clam, hard-shell (or hard-shelled) clam, or the quahog, is an edible marine bivalve mollusk that is native to the eastern shores of North America and Central America from Prince E ...

'' (Linnaeus, 1758) – Northern quahog * '' Mercenaria stimpsoni'' (Gould, 1861) – Venus clam * ''

Mercenaria texana ''Mercenaria'' is a genus of edible saltwater clams, marine bivalve molluscs in the family Veneridae, the Venus clams. The genus ''Mercenaria'' includes the quahogs, consisting of ''Mercenaria mercenaria'', the northern quahog or hard clam, an ...

'' (Dall, 1902)

Fossils species

Several other species are known only from fossils. These mollusk lived from Oligocene to Quaternary (from 23.03 to 0.0 Ma). Fossil shells have been found in the sediments of

Russia Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

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and

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

*''†

Mercenaria blakei ''Mercenaria'' is a genus of edible saltwater clams, marine bivalve molluscs in the family Veneridae, the Venus clams. The genus ''Mercenaria'' includes the quahogs, consisting of ''Mercenaria mercenaria'', the northern quahog or hard clam, an ...

'' Ward 1992 *''† Mercenaria campechiensis'' Gmelin, 1791 **''†Mercenaria campechiensis carolinensis'' Conrad 1875 **''†Mercenaria campechiensis rileyi'' Conrad 1838 **''†Mercenaria campechiensis tridacnoides'' Lamarck 1818 * ''†

Mercenaria capax ''Mercenaria'' is a genus of edible saltwater clams, marine bivalve molluscs in the family Veneridae, the Venus clams. The genus ''Mercenaria'' includes the quahogs, consisting of ''Mercenaria mercenaria'', the northern quahog or hard clam, an ...

'' Conrad 1843 * ''†

Mercenaria cuneata ''Mercenaria'' is a genus of edible saltwater clams, marine bivalve molluscs in the family Veneridae, the Venus clams. The genus ''Mercenaria'' includes the quahogs, consisting of ''Mercenaria mercenaria'', the northern quahog or hard clam, an ...

'' Conrad 1869 * ''†

Mercenaria druidi ''Mercenaria'' is a genus of edible saltwater clams, marine bivalve molluscs in the family Veneridae, the Venus clams. The genus ''Mercenaria'' includes the quahogs, consisting of ''Mercenaria mercenaria'', the northern quahog or hard clam, an ...

'' Ward 1992 * ''†

Mercenaria ducatelli ''Mercenaria'' is a genus of edible saltwater clams, marine bivalve molluscs in the family Veneridae, the Venus clams. The genus ''Mercenaria'' includes the quahogs, consisting of ''Mercenaria mercenaria'', the northern quahog or hard clam, an ...

'' Conrad 1838 * ''†

Mercenaria erecta ''Mercenaria'' is a genus of edible saltwater clams, marine bivalve molluscs in the family Veneridae, the Venus clams. The genus ''Mercenaria'' includes the quahogs, consisting of ''Mercenaria mercenaria'', the northern quahog or hard clam, an ...

'' Kellum 1926 * ''†

Mercenaria gardnerae ''Mercenaria'' is a genus of edible saltwater clams, Marine (ocean), marine bivalve molluscs in the family Veneridae, the Venus clams. The genus ''Mercenaria'' includes the quahogs, consisting of ''Mercenaria mercenaria'', the northern quahog o ...

'' Kellum 1926 * ''† Mercenaria langdoni'' Dall 1900 * ''† Mercenaria nannodes'' Gardner 1947 * ''† Mercenaria permagna'' Conrad 1838 * ''† Mercenaria plena'' Conrad 1869 **''†Mercenaria plena inflata'' Dall 1903 **''†Mercenaria plena nucea'' Dall 1903 * ''† Mercenaria prodroma'' Gardner 1947 * ''† Mercenaria tetrica'' Conrad 1838 Paleobiology Database
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Bibliography

* W. S. Arnold, T. M. Bert, D. C. Marelli, H. Cruz-Lopez, P. A. Gil
Genotype-specific growth of hard clams (genus Mercenaria) in a hybrid zone: variation among habitats
* John Norman Kraeuter, Michael Castagn
Biology of the Hard Clam

References

Veneridae Extant Oligocene first appearances Bivalve genera {{Veneridae-stub