''Chamelea gallina'' 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 ...

of small saltwater

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 she ...

, a marine

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 ...

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 ...

, the venus clams.

Taxonomy

Carl Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...

originally described ''Venus gallina'' from the

Mediterranean Sea The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the ea ...

in 1758. It was not clear whether da Costa's 1778 ''Pectunculus striatulus'' was a different northern species or not. Linnaeus afterwards mentioned that his ''V. gallina'' also occurs in '. In 1952, following Dodge, the name ''Chamelea gallina'' was considered to be valid. There were for a while two recognised subspecies: the Mediterranean'' C. g. gallina'', and the Atlantic ''C. g. striatula''. However by 2016, the two subspecies were elevated to the species level, and listed separately on the database

WoRMS Worms may refer to: *Worm, an invertebrate animal with a tube-like body and no limbs Places *Worms, Germany, a city **Worms (electoral district) *Worms, Nebraska, U.S. *Worms im Veltlintal, the German name for Bormio, Italy Arts and entertainme ...

Characteristics

The shell is solid and thick, with two equal sized

valves A valve is a device or natural object that regulates, directs or controls the flow of a fluid (gases, liquids, fluidized solids, or slurries) by opening, closing, or partially obstructing various passageways. Valves are technically fittings ...

and up to five centimetres long. It is broadly triangular but asymmetrical, having a round anterior margin but a somewhat elongated posterior. The

periostracum The periostracum ( ) is a thin, organic coating (or "skin") that is the outermost layer of the shell of many shelled animals, including molluscs and brachiopods. Among molluscs, it is primarily seen in snails and clams, i.e. in gastropods and ...

is thin and the ligament connecting the two valves is narrow. The lunule is short and heart-shaped, light brown with fine radiating ridges. The shell is sculptured with about fifteen concentric ridges. The colour is whitish, cream or pale yellow, sometimes shiny, and usually with three red-brown radiating rays.

Distribution

''Chamelea gallina'' occurs on Eastern Atlantic coasts, from

Norway Norway, officially the Kingdom of Norway, is a Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of Jan Mayen and t ...

and the

British Isles The British Isles are a group of islands in the North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner and Outer Hebrides, the Northern Isles, ...

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 ...

Morocco Morocco (),, ) officially the Kingdom of Morocco, is the westernmost country in the Maghreb region of North Africa. It overlooks the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to ...

Madeira ) , anthem = ( en, "Anthem of the Autonomous Region of Madeira") , song_type = Regional anthem , image_map=EU-Portugal_with_Madeira_circled.svg , map_alt=Location of Madeira , map_caption=Location of Madeira , subdivision_type=Sovereign st ...

and the

Canary Islands The Canary Islands (; es, Canarias, ), also known informally as the Canaries, are a Spanish autonomous community and archipelago in the Atlantic Ocean, in Macaronesia. At their closest point to the African mainland, they are west of Morocc ...

. It is also found in the

and the

Black Sea The Black Sea is a marginal mediterranean sea of the Atlantic Ocean lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bounded by Bulgaria, Georgia, Roma ...

and is abundant in the

Adriatic Sea The Adriatic Sea () is a body of water separating the Italian Peninsula from the Balkan Peninsula. The Adriatic is the northernmost arm of the Mediterranean Sea, extending from the Strait of Otranto (where it connects to the Ionian Sea) to t ...

Biology

''Chamelea gallina'' lives under the surface of clean and muddy sand at a depth of between five and twenty metres. It is a

filter feeder Filter feeders are a sub-group of suspension feeding animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure. Some animals that use this method of feedin ...

, taking in a variety of

microalgae Microalgae or microphytes are microscopic algae invisible to the naked eye. They are phytoplankton typically found in freshwater and marine systems, living in both the water column and sediment. They are unicellular species which exist indiv ...

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...

and small particles of

detritus In biology, detritus () is dead particulate organic material, as distinguished from dissolved organic material. Detritus typically includes the bodies or fragments of bodies of dead organisms, and fecal material. Detritus typically hosts commun ...

Uses

This species is used for food. In 1995 the total recorded catch was 42,000 tons with the largest catches being taken by Italy and Turkey. The shells are mostly caught with

dredges Dredging is the excavation of material from a water environment. Possible reasons for dredging include improving existing water features; reshaping land and water features to alter drainage, navigability, and commercial use; constructing da ...

but some bottom trawling is done and some

aquaculture Aquaculture (less commonly spelled aquiculture), also known as aquafarming, is the controlled cultivation ("farming") of aquatic organisms such as fish, crustaceans, mollusks, algae and other organisms of value such as aquatic plants (e.g. lot ...

takes place in Italy.

European law

The European Union regulament n° 1667/2006 has forbidden the commerce of clams having a length less than to 25 millimeters. The full list of the forbidden marine species is available as an annex of the

Habitats Directive The Habitats Directive (more formally known as Council Directive 92/43/EEC on the Conservation of natural habitats and of wild fauna and flora) is a directive adopted by the European Community in 1992 as a response to the Berne Convention. The E ...

. The new EU limit to the length of clams came into force in 2010. Two years later, the sanctions started to include a fine until a maximum of 4,000 euros, besides to the seizure of the catch and the closure of the activity. The norm recalled a decree adopted by the Italian President Saragat in 1968 and created a severe economic damage for the Italian enterprises belonging to the ittic sector, characterized by a production of clams 22 millimeters long. That type of clam is an historic production of the

mainly in

Venice Venice ( ; it, Venezia ; vec, Venesia or ) is a city in northeastern Italy and the capital of the Veneto Regions of Italy, region. It is built on a group of 118 small islands that are separated by canals and linked by over 400 ...

and

Chioggia Chioggia (; vec, Cióxa , locally ; la, Clodia) is a coastal town and ''comune'' of the Metropolitan City of Venice in the Veneto region of northern Italy. Geography The town is situated on a small island at the southern entrance to the L ...

, but also in

Rimini Rimini ( , ; rgn, Rémin; la, Ariminum) is a city in the Emilia-Romagna region of northern Italy and capital city of the Province of Rimini. It sprawls along the Adriatic Sea, on the coast between the rivers Marecchia (the ancient ''Ariminu ...

and the Romagnole Coast), and even in

Campania Campania (, also , , , ) is an administrative Regions of Italy, region of Italy; most of it is in the south-western portion of the Italian peninsula (with the Tyrrhenian Sea to its west), but it also includes the small Phlegraean Islands and the i ...

due to the

climate change In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...

and a new different mean

saltiness The gustatory system or sense of taste is the sensory system that is partially responsible for the perception of taste (flavor). Taste is the perception produced or stimulated when a substance in the mouth reacts chemically with taste receptor ...

of the Italian seas. which blocks the adult claim's growth at a diameter of around 22 mm. Against an intensive

lobbying In politics, lobbying, persuasion or interest representation is the act of lawfully attempting to influence the actions, policies, or decisions of government officials, most often legislators or members of regulatory agency, regulatory agencie ...

activity of the Spanish deputies at the

European Parliament The European Parliament (EP) is one of the legislative bodies of the European Union and one of its seven institutions. Together with the Council of the European Union (known as the Council and informally as the Council of Ministers), it adopts ...

, in June 2016 the Italian parties reached a temporary triennal exception to the limit, in order to avoid the crisis of the ittic sector and to protect an Italian typical production. On 9 October 2019, the exception was firstly delayed for another year until 31 December 2020. Italian organizations are pressing to the EU Parliament to concede a new dispensation form the limit of 25 millimeters.

References

External links

Habiats.org.uk
images {{Taxonbar, from=Q2948502 Veneridae Molluscs described in 1758 Taxa named by Carl Linnaeus