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 exploited as food sources.

Veneridae
A valve of Venus verrucosa
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Bivalvia
Subclass: Heterodonta
Order: Venerida
Superfamily: Veneroidea
Family: Veneridae
Rafinesque, 1815
Genera

See text

Left valve dentition of the shell of the venerid Mercenaria mercenaria

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.

Classification

The classification within the family Veneridae has been controversial at least since the 1930s. The most used classification is that of Keen (1969) which recognises 12 subfamilies, listed below. 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.

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.[1]

Subfamilies according to Keen (1969)
  • Chioninae
  • Circinae
  • Clementinae
  • Cyclininae
  • Dosiniinae
  • Gemminae
  • Meretricinae
  • Pitarinae
  • Samarangiinae
  • Sunettinae
  • Tapetinae
  • Venerinae

List of genera in the family Veneridae
Marcia marmorata
Sunetta meroe
  • Agriopoma Dall, 1902
  • Amiantis Carpenter, 1884
  • Anomalocardia Schumacher, 1817
  • Anomalodiscus Dall, 1902
  • Antigona Schumacher, 1817
  • Aphrodora Jukes-Browne, 1914
  • Asaphinoides F. Hodson, 1931
  • †Atamarcia Marwick, 1927
  • Austrovenus Finlay,1927
  • Bassina Jukes-Browne, 1914
  • Callista Poli, 1791
  • Callithaca Dall, 1902
  • Callocardia A. Adams, 1864
  • Callpita M. Huber, 2010
  • Chamelea Mörch, 1853
  • Chione Megerle von Mühlfeld, 1811
  • †Chionella Cossmann, 1886
  • Chioneryx Iredale, 1924
  • Chionista Keen, 1958
  • Chionopsis Olsson, 1932
  • Choristodon Jonas, 1844
  • Circe Schumacher, 1817
  • Circenita Jousseaume, 1888
  • Circomphalus Klein, 1853
  • Clausinella J. E. Gray, 1851
  • Clementia Gray, 1842
  • Compsomyax Stewart, 1930
  • Comus Cox, 1930
  • Cooperella Carpenter, 1864
  • Costacallista Palmer, 1927
  • Costellipitar Habe, 1951
  • Cryptonema (bivalve) Jukes-Browne, 1914
  • Cyclina Deshayes, 1850
  • Cyclinella Dall, 1902
  • Dorisca Dall, Bartsch & Rehder, 1938
  • Dosina Gray, 1835
  • Dosinia Scopoli, 1777
  • Egesta Conrad, 1845
  • Eumarcia Iredale, 1924
  • Eurhomalea Cossmann, 1920
  • Ezocallista Kira, 1959
  • †Flaventia Jukes-Browne, 1908
  • †Frigichione Fletcher, 1938
  • Gafrarium Röding, 1798
  • Gemma Deshayes, 1853
  • Globivenus Coen, 1934
  • Gomphina Mörch, 1853
  • Gomphinella Marwick, 1927
  • Gouldia C. B. Adams, 1847
  • Gouldiopa Iredale, 1924
  • Granicorium Hedley, 1906
  • †Grateloupia [anonymous], 1830
  • †Hinemoana Marwick, 1927
  • Humilaria Grant and Gale, 1931
  • Hyphantosoma Dall, 1902
  • Hysteroconcha Dall, 1902
  • Iliochione Olsson, 1961
  • Irus Schmidt, 1818
  • Irusella Hertlein and Grant, 1972
  • Jukesena Iredale, 1915
  • Katelysia Römer, 1857
  • †Katherinella Tegland, 1929
  • Kyrina Jousseaume, 1894
  • Laevicirce Habe, 1951
  • Lajonkairia Deshayes, 1854
  • Lamelliconcha Dall, 1902
  • Lepidocardia Dall, 1902
  • Leukoma Römer, 1857
  • Lioconcha Morch, 1853
  • Liocyma Dall, 1870
  • Lirophora Conrad, 1883
  • Macridiscus Dall, 1902
  • Macrocallista Meek, 1876
  • Marcia H. Adams & A. Adams, 1857
  • †Marwickia Finlay, 1930
  • Megapitaria Grant & Gale, 1931
  • Mercenaria Schumacher, 1817
  • Meretrix Linnaeus, 1758
  • †Meroena Jukes-Browne, 1908
  • Microcirce Habe, 1951
  • Mysia Lamarck, 1818
  • Notocallista Iredale, 1924
  • Nutricola Bernard, 1982
  • †Paleomarcia Fletcher, 1938
  • Panchione Olsson, 1964
  • Paphia Born, 1778
  • Paphonotia Hertlein & Strong, 1948
  • Parastarte Conrad, 1862
  • Paratapes Stoliczka, 1870
  • Parvicirce Cosel, 1995
  • Pelecyora Dall, 1902
  • Periglypta Jukes-Browne, 1914
  • Petricola Lamarck, 1801
  • Petricolaria Stoliczka, 1870
  • Pitar Römer, 1857
  • Pitarenus Rehder & Abbott, 1951
  • Placamen Iredale, 1925
  • Polititapes Chiamenti, 1900
  • Privigna Dall, Bartsch & Rehder, 1938
  • Protapes Dall, 1902
  • Protocallithaca Nomura, 1937
  • Proxichione Iredale, 1929
  • Psephidia Dall, 1902
  • Redicirce Iredale, 1924
  • †Rohea Marwick, 1938
  • Ruditapes Chiamenti, 1900
  • Samarangia Dall, 1902
  • Saxidomus Conrad, 1837
  • Sunetta Link, 1807
  • Sunettina Pfeiffer, 1869
  • Tapes Muhlfeld, 1811
  • Tawera Marwick, 1927
  • Timoclea Brown, 1827
  • Tivela Link, 1807
  • Transennella Dall, 1883
  • Transenpitar Fischer-Piette & Testud, 1967
  • †Turia Marwick, 1927
  • Turtonia Alder, 1848
  • Veneriglossa Dall, 1886 [temporary name]
  • Venerupis Lamarck, 1818
  • Venus Linnaeus, 1758

References
  1. 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
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