The grooved carpet shell, or Palourde clam, ''Ruditapes decussatus'', or ''Venerupis decussatus'', is a

clam Clam is a common name for several kinds of bivalve molluscs. The word is often applied only to those that are edible and live as infauna, spending most of their lives halfway buried in the sand of the seafloor or riverbeds. Clams have two shel ...

( bivalve mollusc) in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

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 ex ...

. It is distributed worldwide and due to its ecological and economic interest has been proposed as a

bioindicator A bioindicator is any species (an indicator species) or group of species whose function, population, or status can reveal the qualitative status of the environment. The most common indicator species are animals. For example, copepods and other sma ...

. 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.

Description

The

shell Shell may refer to: Architecture and design * Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses ** Thin-shell structure Science Biology * Seashell, a hard o ...

is broadly oval to quadrate with the umbones distinctly anterior. The posterior hinge line is straight, the posterior margin truncate, and the anterior hinge line grades into the down-sloping anterior margin. It is prominent posteriorly, where the shell is conspicuously decussate. The surface has a

sculpture Sculpture is the branch of the visual arts that operates in three dimensions. Sculpture is the three-dimensional art work which is physically presented in the dimensions of height, width and depth. It is one of the plastic arts. Durable ...

of fine concentric striae and bolder radiating lines. Growth stages are clear. The lunule and escutcheon are poorly defined. Each valve has three cardinal teeth: the centre one in the left valve, and centre and posterior in right are bifid. The pallial line and adductor scars are distinct. The pallial sinus is U-shaped, not extending beyond the midline of the shell, but reaching a point below the posterior part of the ligament. The lower limb of the sinus is distinct from the pallial line for the whole of its length. The inner surfaces of the shell are glossy white, often with yellow or orange tints, and with a bluish tinge along the dorsal edge. The overall color is cream, yellowish, or light brown, often with darker markings.FAO Species Identification and Data Programme (SIDP) - Fisheries and Aquaculture Department
/ref>

Location

Despite improper management in the past, some regions in the Atlantic coast of the

Iberian Peninsula The Iberian Peninsula (), ** * Aragonese and Occitan: ''Peninsula Iberica'' ** ** * french: Péninsule Ibérique * mwl, Península Eibérica * eu, Iberiar penintsula also known as Iberia, is a peninsula in southwestern Europe, def ...

, including Portugal's

Algarve The Algarve (, , ; from ) is the southernmost NUTS II region of continental Portugal. It has an area of with 467,495 permanent inhabitants and incorporates 16 municipalities ( ''concelhos'' or ''municípios'' in Portuguese). The region has it ...

Spain , image_flag = Bandera de España.svg , image_coat = Escudo de España (mazonado).svg , national_motto = ''Plus ultra'' (Latin)(English: "Further Beyond") , national_anthem = (English: "Royal March") , i ...

's Galicia and of the Mediterranean basin, as well as

Ireland Ireland ( ; ga, Éire ; Ulster Scots dialect, Ulster-Scots: ) is an island in the Atlantic Ocean, North Atlantic Ocean, in Northwestern Europe, north-western Europe. It is separated from Great Britain to its east by the North Channel (Grea ...

, currently have solid populations of ''Ruditapes decussatus''.Global Biodiversity Information
/ref>

Uses

''Ruditapes decussatus'' is cultured from the

Atlantic The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe an ...

coast of

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan area ...

Portugal Portugal, officially the Portuguese Republic ( pt, República Portuguesa, links=yes ), is a country whose mainland is located on the Iberian Peninsula of Southwestern Europe, and whose territory also includes the Atlantic archipelagos of ...

and in the Mediterranean basin. It is often grown with other bivalves ('' Venerupis pullastra'', '' Venerupis rhomboides'', '' Venerupis aurea'', '' Dosinia exoleta'' and '' Tellina incarnata''). Their main predators are shore crabs (''

Carcinus maenas ''Carcinus maenas'' is a common littoral crab. It is known by different names around the world. In the British Isles, it is generally referred to as the shore crab, or green shore crab. In North America and South Africa, it bears the name europ ...

''); starfish (''

Asterias rubens The common starfish, common sea star or sugar starfish (''Asterias rubens'') is the most common and familiar starfish in the north-east Atlantic. Belonging to the family Asteriidae, it has five arms and usually grows to between 10–30 ...

'' and '' Marthasterias glacialis''); gastropods (Natica sp.); and birds (Larus sp). An individual ''Carcinus maenas'' (6.5 cm width) can consume 5 or 6 clams per day. Marine aquaculture production of grooved carpet shell in 2003 was 3,007 t in Portugal, which excludes non-aquaculture harvesting of the species. Between 1997 and 2001 total aquaculture production varied between 3,700 and 4,900 tonnes, from five countries. Most was produced by

but

and

have also been significant producers; however, the contribution from France is now much lower than before; in 1995 it was by far the leading producer with nearly 5,200 tonnes but in 2004 it produced only 475 tonnes. Global production seems to be declining; in 2004 it was only 2,700 tonnes but the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the European mainland, continental mainland. It comprises England, Scotlan ...

had appeared as a minor producer. It is consumed fresh and canned.

References

Bibliography

* Garcia, F. – 1993. Interprétation des stries valvaires pour l'évaluation de la croissance de Ruditapes decussatus L. Oceanologica Acta . 16: 199–203.. * Poppe, G. T. & Goto, Y. – 1991. European seashells. Vol 1 (Polyplacophora, Caudofoveata, Solenogastra, Gastropoda).Verlag Christa Hemmen . * Rodriguez-Moscoso, E & Arnaiz, R – 1998. Gametogenesis and energy storage in a population of the grooved carpet-shell clam, Tapes decussatus (Linne, 1787), in northwest Spain. Aquaculture. . vol. 162, no. 1–2, pp. 125–139 .. * Xie, Qiushi & Burnell, GM – 1994. A comparative study of the gametogenic cycles of the clams Tapes philippinarum ( A. Adams & Reeve 1850) and Tapes decussatus (Linnaeus) on the south coast of Ireland. Journal of Shellfish Research. . vol. 13, no. 2, pp. 467–472.. {{Taxonbar, from=Q2724656 Aquaculture Veneridae Marine molluscs of Europe Commercial molluscs Molluscs described in 1758 Taxa named by Carl Linnaeus