''Venerupis corrugata'', the pullet carpet shell, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

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 ...

in the

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

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 ...

. It is found buried in the sediment on the sea bed in shallow parts of the eastern Atlantic Ocean. It is harvested for human consumption in Spain and other parts of Western Europe.

Description

The pullet carpet shell has a pair of hinged, oblong valves that grow to about in length. The umbone/beak is about one third of the way along the shell. The anterior part of the hinge forms an angle with the posterior part and there are 3 cardinal teeth on each valve. The shell is sculptured on the outside with fine radial ribs running from the umbone to the margin and with fine concentric striations. The colour is cream, grey or pale brown, sometimes with irregular streaks or rays of darker colour. The inside of the shell is glossy white, sometimes with purple markings near the umbone. The adductor muscle scars and the pallial line are clearly visible and there is a large, rounded pallial sinus. The siphons are joined for their full length, a fact that distinguishes this species from the otherwise similar ''

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

''.

Distribution and habitat

This species is found in shallow waters in the East Atlantic and the Mediterranean Sea. The clam's range extends from the coasts of Norway south to West Africa. It lives in a shallow burrow just under the surface in sand, mud or gravel. It occurs in the intertidal zone down to about .

Biology

This bivalve extends its siphons to the surface of the sediment in which it is buried, and draws in water through one of them and expels it through the other. While the water is passing through the gills,

phytoplankton Phytoplankton () are the autotrophic (self-feeding) components of the plankton community and a key part of ocean and freshwater ecosystems. The name comes from the Greek words (), meaning 'plant', and (), meaning 'wanderer' or 'drifter'. Ph ...

and other organic food particles are filtered out. Individuals clams are either male or female, and breeding takes place mostly in summer by the liberation of gametes into the water. The resulting larvae drift with the currents as part of the

plankton Plankton are the diverse collection of organisms found in Hydrosphere, water (or atmosphere, air) that are unable to propel themselves against a Ocean current, current (or wind). The individual organisms constituting plankton are called plankt ...

for about two weeks before settling on the seabed, undergoing

metamorphosis Metamorphosis is a biological process by which an animal physically develops including birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Some inse ...

and becoming juveniles known as "spat".

Fishery

The pullet carpet shell is cultivated in Spain, Portugal, France and Italy for human consumption. The clam fishing industry in Spain grew rapidly in 1926 and 1927 with clams of all sizes being dug out of the sands indiscriminately. By 1956, 250 boats were involved in the industry near San Simon in Galicia. In subsequent years, over-harvesting caused a drop in natural populations. Currently farmers in the area have "parks", areas of the seabed that they cultivate and maintain. Hatcheries rear larvae and the resulting spat is grown on in nurseries. The small clams are then seeded onto the seabed, where the animals quickly bury themselves. Maintenance consists of removing

seaweed Seaweed, or macroalgae, refers to thousands of species of macroscopic, multicellular, marine algae. The term includes some types of '' Rhodophyta'' (red), ''Phaeophyta'' (brown) and ''Chlorophyta'' (green) macroalgae. Seaweed species such as ...

, restricting

predation Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the ...

crab Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen) ( el, βραχύς , translit=brachys = short, / = tail), usually hidden entirely under the thorax. They live in all the ...

s and

starfish Starfish or sea stars are star-shaped echinoderms belonging to the class Asteroidea (). Common usage frequently finds these names being also applied to ophiuroids, which are correctly referred to as brittle stars or basket stars. Starfish ...

, and ensuring that the sediment is sufficiently oxygenated. Harvesting is done 12 to 28 months after seeding, using specially designed shovels and rakes. The clam's diet consists of a variety of algae, but is found that the species ''Isochrysis'' is the best for the growth and development of this species of clam.

References

{{Taxonbar, from=Q14513297 Veneridae Bivalves described in 1791 Taxa named by Johann Friedrich Gmelin