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.

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.

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

See text

MercenariaDentition081111
Left valve dentition of the shell of the venerid 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

CretaceousVenerid
Venerid bivalve; Wadi Umm Ghudran Formation (Late Cretaceous, early Campanian), near Amman, Jordan
CretaceousVeneridDentition
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 001
Marcia marmorata
Sunetta meroe 002
Sunetta meroe

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

Gallery

Dosinia anus (ringed dosinia)

Dosinia anus from New Zealand, a member of the Dosiniinae

Chamelea striatula

Chamelea striatula

External links

Austrovenus stutchburyi

Austrovenus stutchburyi, common name the New Zealand cockle or New Zealand little neck clam, is an edible saltwater clam, a marine bivalve mollusc in the family Veneridae, the Venus clams.

Chione (bivalve)

Chione is a genus of American tropical marine bivalve molluscs, in the family Veneridae.

Dosinia

Dosinia is a genus of saltwater clams, marine bivalve molluscs in the family Veneridae, subfamily Dosiniinae Deshayes, 1853. The shell of Dosinia species is disc-like in shape, usually white, and therefore is reminiscent of the shells of Lucinid bivalves.

The genus is known from the Cretaceous to the Recent periods (age range: 99.7 to 0.0 million years ago). Fossils of species within this genus have been found all over the world.

Grooved carpet shell

The grooved carpet shell or Palourde clam, Ruditapes decussatus or Venerupis decussatus, is a clam or bivalve mollusc in the family Veneridae. It is distributed worldwide and due to its ecological and economic interest has been proposed as a bioindicator.

This species is one of the most popular and profitable mollusc of lagoonal and coastal sites in the Mediterranean, where it was collected for a long time as food. It is consumed fresh and canned.

Hard clam

The hard clam (Mercenaria mercenaria), also known as a quahog (; or quahaug), round clam, or hard-shell (or hard-shelled) clam, is an edible marine bivalve mollusc that is native to the eastern shores of North America and Central America, from Prince Edward Island to the Yucatán Peninsula. It is one of many unrelated edible bivalves that in the United States are frequently referred to simply as clams, as in the expression "clam digging". Older literature sources may use the systematic name Venus mercenaria; this species is in the family Veneridae, the venus clams.

Confusingly, the "ocean quahog" is a different species, Arctica islandica, which, although superficially similar in shape, is in a different family of bivalves: it is rounder than the hard clam, usually has black periostracum, and there is no pallial sinus in the interior of the shell.

Leukoma

Leukoma is a genus of saltwater clams, marine bivalve mollusks in the family Veneridae, the Venus clams. This genus of bivalves has been exploited by humans since prehistory; for example, the Chumash peoples of California harvested this genus from Morro Bay in approximately 1000 AD.

Macrocallista

Macrocallista is a genus of saltwater clams, marine bivalve mollusks in the family Veneridae, the Venus clams.

Macrocallista maculata

Macrocallista maculata, or the calico clam, is a species of bivalve mollusc in the family Veneridae. It can be found along the Atlantic coast of North America, ranging from North Carolina to Bermuda and Brazil.

The Calico Clam has been protected from harvesting in Bermuda since the 1970s (see Fisheries Protected Species Order 1978).

Mercenaria

Mercenaria is a genus of edible saltwater clams, marine bivalve molluscs in the family Veneridae, the Venus clams.

The genus Mercenaria includes the quahogs, Mercenaria mercenaria, the northern quahog or hard clam, 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 M. stimpsoni found in north Pacific waters.

All these species were formerly placed in the related genus Venus.

Pacific razor clam

The Pacific razor clam, Siliqua patula, is a species of large marine bivalve mollusc in the family Pharidae.

Paphia

Paphia is a genus of saltwater clam, a marine bivalve mollusk in the family Veneridae, the Venus clams.

This genus is known in the fossil records from the Cretaceous to the Quaternary (age range: from 112.6 to 0.0 million years ago).

Periglypta

Periglypta is a genus of bivalves in the family Veneridae.

Pitar

Pitar is a genus of saltwater clams, marine venerid bivalve molluscs in the family Veneridae, the Venus clams. This genus contains over 60 species.

Ruditapes largillierti

Ruditapes largillierti is a saltwater clam, a marine bivalve mollusc in the family Veneridae, the Venus clams. Moderately large for genus (45–65 mm long), elongate and subrectangular, thick and solid, with smooth ventral margin.It has limited use to people and the seafood industry because it resides in very deep Ocean water and contains a very common pearl.

Saxidomus nuttalli

Saxidomus nuttalli is a species of large edible saltwater clam, a marine bivalve mollusk in the family Veneridae, the venus clams. Common names include California butterclam and Washington clam.This clam is native to the west coast of North America, its distribution extending from northern California to Baja California.This is a commercially exploited species that attains a length of approximately 15 cm.

Smooth clam

The smooth clam, Callista chione, (also sometimes classified as Cytherea chione or Meretrix chione) is a rather large, temperate, marine, bivalve mollusc that inhabits sandy bottoms or with small pebbles in clean waters down to about 200 m from the British Isles to the Mediterranean.[1] The shell can reach up to about 110 mm Ø, its outer side is smooth and ranges from light greenish creamy colour to medium brown [2], probably varies to match the background; the interior is white to soft pink. The concentric and radial growth lines are easily seen. Callista chione is edible, different dishes are prepared throughout the Mediterranean in Spain, Italy, France, the Balkan and the Magreb countries. It has been found that, as is the case with many bivalve molluscs, which are filter-feeders, (they feed by filtering food particles from the water), that Callista chione, common in fish markets in the Mediterranean, concentrates toxins from dinoflagellates blooms associated with pollution events such as red tides [3], sewage water, old sediment dredging, ship ballast water dumping, etc. These toxins cannot be eliminated by the traditional cleansing of shellfish in clean water or by cooking, and can be responsible for complex human health problems: respiratory ailments, skin rashes, even paralysis, etc., such as it is known now to have occurred in New Orleans, associated with the contact or ingestion of severely contaminated water, left by Katrina. The commonest of these dangers is known as PSP or paralytic shellfish poisoning.

Tivela

Tivela is a genus of saltwater clams, marine bivalve mollusks in the family Veneridae, the Venus clams.

Venerupis

Venerupis is a genus of marine bivalve molluscs in the family Veneridae, commonly known as carpet shells. The valves are robust and rhomboidal with the umbones turned-in and nearer the anterior end. The posterior end is wedge-shaped and the internal margins of the valves are smooth. There are 3 or 4 cardinal teeth on each valve. The foot is large and the siphons are of medium length and united except at the very tip.

Venerupis philippinarum

Venerupis philippinarum (syn. Ruditapes phlippinarum) is an edible species of saltwater clam in the family Veneridae, the Venus clams.

Common names for the species include Manila clam, Japanese littleneck clam, Japanese cockle, and Japanese carpet shell.This clam is commercially harvested, being the second most important bivalve grown in aquaculture worldwide.

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