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Veneridae
	Left valve of Venus verrucosa
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Bivalvia
Order:	Venerida
Superfamily:	Veneroidea
Family:	Veneridae; Rafinesque, 1815
Genera
	See text

Left valve dentition of the shell of the venerid *Mercenaria mercenaria*

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 exploited as food sources.

Many of the most important edible species are commonly known (in the USA) simply as "clams". Venerids make up a significant proportion of the world fishery of edible bivalves. The family includes some species that are important commercially, such as (in the USA) the hard clam or quahog, Mercenaria mercenaria.

Taxonomy

The classification within the family Veneridae has been controversial at least since the 1930s. Molecular approaches show that much of this traditional classification is unnatural.^[1] Some common species have been moved between genera (including genera in different subfamilies) because of repeated attempts to bring a more valid organization to the classification or taxonomy of the family, therefore changes in the generic name of species are frequently encountered.

The characters used for classifying this group still tend to be superficial, focusing on external features, especially those of the shell. Venerid clams are characterized as bivalves with an external posterior ligament, usually a well demarcated anterior area known as the lunule, and three interlocking structures (called cardinal teeth) in the top of each valve; several of the subfamilies also have anterior lateral teeth, anterior to the cardinal teeth: one in the left valve, and two (sometimes obscure) in the right valve. The inner lower peripheries of the valves can be finely toothed or smooth.

Classification

The following genera are recognised in the family Veneridae:^[2]

Subfamily Callocardiinae Dall, 1895

Agriopoma Dall, 1902
Amiantis P. P. Carpenter, 1864
Aphrodora Jukes-Browne, 1914
†Austrocallista S. Erdmann & Morra, 1985
Callista Poli, 1791
Callocardia A. Adams, 1864
Callpita M. Huber, 2010
Costellipitar Habe, 1951
†Dollfusia Cossmann, 1886
†Dosiniopsis Conrad 1864
†Eocallista Douvillé, 1921
Eucallista Dall, 1902
Ezocallista Kira, 1959
†Goshoraia Tamura, 1977
Hyphantosoma Dall, 1902
Hysteroconcha Dall, 1902
Lamelliconcha Dall, 1902
Lioconcha Mörch, 1853
Macrocallista Meek, 1876
†Marwickia Finlay, 1930
Megapitaria U. S. Grant & Gale, 1931
Notocallista Iredale, 1924
Nutricola F. R. Bernard, 1982
Pelecyora Dall, 1902
Pitar Römer, 1857
Pitarenus Rehder & Abbott, 1951
Proteopitar Alvarez, del Río & Martínez, 2019
†Rohea Marwick, 1938
Saxidomus Conrad, 1837
Transennella Dall, 1884
Transenpitar Fischer-Piette & Testud, 1967
Veneriglossa Dall, 1886

Subfamily Clementiinae Frizzell, 1936

Clementia Gray, 1842
Compsomyax Stewart, 1930
Egesta Conrad, 1845
Kyrina Jousseaume, 1894

Subfamily Cyclininae Frizzell, 1936

Cyclina Deshayes, 1850
†Cyprimeria Conrad, 1864

Subfamily Dosiniinae Deshayes, 1853

†Cordiopsis Cossmann, 1910
Cyclinella Dall, 1902
Dosinia Scopoli, 1777
†Dosinobia Finlay & Marwick, 1937
†Kakahuia Marwick, 1927

Subfamily Gemminae Dall, 1895

Gemma Deshayes, 1853
Parastarte Conrad, 1862
†Plesiastarte P. Fischer, 1887

Subfamily Gouldiinae Stewart, 1930

Circe Schumacher, 1817
Circenita Jousseaume, 1888
Comus L. R. Cox, 1930
Dorisca Dall, Bartsch & Rehder, 1938
Gafrarium Röding, 1798
Gouldia C. B. Adams, 1847
Gouldiopa Iredale, 1924
Laevicirce Habe, 1951
Microcirce Habe, 1951
Parvicirce Cosel, 1995
Privigna Dall, Bartsch & Rehder, 1938
Redicirce Iredale, 1936

Subfamily Meretricinae Gray, 1847

Aeora Conrad, 1870
†Eomeretrix F. E. Turner, 1938
Gomphina Mörch, 1853
†Gratelupia Desmoulins, 1828
†Meretrissa Jukes-Browne, 1908
Meretrix Lamarck, 1799
†Titomaya M. J. Alvarez & del Río, 2021
Tivela Link, 1807
†Tivelina Cossmann, 1886

Subfamily Petricolinae d'Orbigny, 1840

Asaphinoides F. Hodson, 1931
Choristodon Jonas, 1844
Cooperella P. P. Carpenter, 1864
Lajonkairia Deshayes, 1855
Mysia Lamarck, 1818
Petricola Lamarck, 1801
Petricolaria Stoliczka, 1870

Subfamily Samarangiinae Keen, 1969

Granicorium Hedley, 1906
Samarangia Dall, 1902

Subfamily Sunettinae Stoliczka, 1870

Sunetta Link, 1807

Subfamily Tapetinae Gray, 1851

†Adelfia M. J. Alvarez & del Río, 2020
†Atamarcia Marwick, 1927
Cryptonema Jukes-Browne, 1914
†Cyclorismina Marwick, 1927
Eumarcia Iredale, 1924
†Gomphomarcia Kautsky, 1929
Irus F. C. Schmidt, 1818
Irusella Hertlein & U. S. Grant, 1972
Katelysia Römer, 1857
†Legumen Conrad, 1858
Liocyma Dall, 1870
Macridiscus Dall, 1902
Marcia H. Adams & A. Adams, 1857
†Marciachlys M. J. Alvarez & del Río, 2020
†Myrsopsis Sacco, 1900
†Neovenerella Goncharova, 1986
†Paleomarcia Fletcher, 1938
Paphia Röding, 1798
Paratapes Stoliczka, 1870
Polititapes Chiamenti, 1900
Protapes Dall, 1902
Ruditapes Chiamenti, 1900
Tapes Megerle von Mühlfeld, 1811
†Taurotapes Sacco, 1900
†Venerella Cossmann, 1886
†Veneritapes Cossmann, 1886
Venerupis Lamarck, 1818

Subfamily Turtoniinae Clark, 1855

Turtonia Alder, 1848

Subfamily Venerinae Rafinesque, 1815

Ameghinomya Ihering, 1907
Anomalocardia Schumacher, 1817
Anomalodiscus Dall, 1902
Antigona Schumacher, 1817
Austrovenus Finlay, 1926
Bassina Jukes-Browne, 1914
Callithaca Dall, 1902
Chamelea Mörch, 1853
Chione Megerle von Mühlfeld, 1811
Chioneryx Iredale, 1924
Chionista Keen, 1958
Chionopsis Olsson, 1932
Circomphalus Mörch, 1853
Clausinella Gray, 1851
Dosina J. E. Gray, 1835
Eurhomalea Cossmann, 1920
Globivenus Coen, 1934
†Hinemoana Marwick, 1927
Humilaria U. S. Grant & Gale, 1931
Iliochione Olsson, 1961
†Kuia Marwick, 1927
Leukoma E. Römer, 1857
Lirophora Conrad, 1863
†Marama Marwick, 1927
Mercenaria Schumacher, 1817
Panchione Olsson, 1964
Paphonotia Hertlein & A. M. Strong, 1948
Periglypta Jukes-Browne, 1914
Placamen Iredale, 1925
Protocallithaca Nomura, 1937
Proxichione Iredale, 1929
Retrotapes del Rio, 1997
Tawera Marwick, 1927
Timoclea T. Brown, 1827
†Turia Marwick, 1927
Venus Linnaeus, 1758

Incertae sedis

†Aphrodina Conrad, 1869
†Austrocardilanx R. N. Gardner, 2005
†Callistina Jukes-Browne, 1908
†Ergenica Goncharova, 1981
†Frigichione Fletcher, 1938
†Katherinella Tegland, 1929
†Loxo Dailey & Popenoe, 1966
†Meroena Jukes-Browne, 1908
†Psathura Deshayes, 1858
†Pseudamiantis Kuroda, 1933
†Rzehakia Korobkov, 1954
†Trigonocallista Rennie, 1930
†Urbnisia Goncharova, 1981

Description

Venerid bivalve; Wadi Umm Ghudran Formation (Late Cretaceous, early Campanian), near Amman, Jordan

Dentition of venerid bivalve; Wadi Umm Ghudran Formation (Late Cretaceous, early Campanian), near Amman, Jordan

Shell sculpture tends to be primarily concentric, but radial and divaricating ornamentation (see Gafrarium), and rarely spines (Pitar lupanaria for example) occur on some. One small subfamily, the Samarangiinae, is created for a unique and rare clam found in coral reefs with an outer covering of cemented sand or mud that texturally camouflages it while enhancing the thickness of the shell. Several venerid clams have overall shell shapes adapted to their environments. Tivela species, for example, have the triangular outline of the surf clams in other bivalve families, and occur often in surf zones. Some Dosinia species are almost disc-like in shape and reminiscent of lucinid bivalves; both types of circular bivalves tend to burrow relatively deeply into the sediment. Further reclassification is to be expected as the results of current research in molecular systematics on the group appear in the literature.

Venerids have rounded or oval solid shells with the umbones (projections) inturned towards the anterior end. Three or four cardinal teeth are on each valve. The siphons are short and united, except at the tip, and are not very long. The foot is large.^[3]

References

^ Chen, Jun; Li, Qi; Kong, Lingfeng; Zheng, Xiaodong (May 2011). "Molecular phylogeny of venus clams (Mollusca, Bivalvia, Veneridae) with emphasis on the systematic position of taxa along the coast of mainland China: Molecular phylogeny of venus clams". Zoologica Scripta. 40 (3): 260–271. doi:10.1111/j.1463-6409.2011.00471.x. S2CID 82676170.
^ "WoRMS - World Register of Marine Species - Veneridae Rafinesque, 1815". www.marinespecies.org. Retrieved 23 November 2022.
^ Barrett, J. H. and C. M. Yonge, 1958. Collins Pocket Guide to the Sea Shore. P. 158. Collins, London

Keen, A. M. (1969). Superfamily Veneracea. pp. 670–690, in: Leslie Reginald Cox et al., Part N [Bivalvia], Mollusca 6, vols. 1 and 2: xxxvii + 952 pp. Part of Raymond C. Moore, ed., Treatise on Invertebrate Paleontology. Lawrence, Kansas (Geological Society of America & University of Kansas).
Powell A. W. B., New Zealand Mollusca, William Collins Publishers Ltd, Auckland, New Zealand 1979 ISBN 0-00-216906-1