''Atrina seminuda'', the half-naked pen shell, is a species of

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 ...

Pinnidae The Pinnidae are a taxonomic family of large saltwater clams sometimes known as pen shells. They are marine bivalve molluscs in the order Pteriida. Shell description The shells of bivalves in this family are fragile and have a long and triang ...

Description

It is characterized by a large shell between about 150–200 mm in triangular or wedge, the leaflets have ornamentations forming rows 10-20 tubular radial spiny projections which are often slightly curved. The surface of the leaflets tend to observe fine markings which correspond to the long lines. The coloration is variable ranging from dark brown to greenish brown. In the animal body highlights large posterior adductor muscle development, which in individuals of sizes between 150 and 200 mm can reach a diameter of about 40 mm.Lodeiros Seijos, J.M., Marin Espinosa, Baumar. y Prieto Arcas, Antulio. 1999: Catalogo de moluscos marinos de las costas nororientales de Venezuela: Clase Bivalvia. Asociación de Profesores de la Universidad de Oriente, Cumaná - Venezuela 112p.Macsotay O. & Campos. R. 2001. Moluscos representativos de la plataforma de Margarita. Editora Rivolta. Valencia. 280p.

Distribution

It can be found along the Atlantic coast of North America, ranging from

North Carolina North Carolina () is a state in the Southeastern region of the United States. The state is the 28th largest and 9th-most populous of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, Georgia and So ...

Texas Texas (, ; Spanish language, Spanish: ''Texas'', ''Tejas'') is a state in the South Central United States, South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2 ...

and south to

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

. For the Venezuelan Caribbean has been appointed to the coasts of the states of Vargas, Miranda,

Anzoátegui ) , anthem = '' Himno del Estado Anzoátegui'' , image_map = Anzoategui in Venezuela.svg , map_alt = , map_caption = Location within Venezuela , pushpin_map = , pushpin_map_a ...

Sucre Sucre () is the Capital city, capital of Bolivia, the capital of the Chuquisaca Department and the List of cities in Bolivia, 6th most populated city in Bolivia. Located in the south-central part of the country, Sucre lies at an elevation of . T ...

and

Nueva Esparta The Nueva Esparta State (in Spanish: ''Estado Nueva Esparta'', ), is one of the 23 states of Venezuela. It comprises Margarita Island, Coche, and the largely uninhabited Cubagua. The state has the smallest area, and is located off the northe ...

Habitat

''Atrina seminuda'', is an endobenthic inhabitant, usually secured by a strong

byssus A byssus () is a bundle of filaments secreted by many species of bivalve mollusc that function to attach the mollusc to a solid surface. Species from several families of clams have a byssus, including pen shells (Pinnidae), true mussels (Mytilid ...

secreted by the animal in rocks and gravel substrate in areas of high energy. Associated with the outer faces of the leaflets of ''Atrina seminuda'' usually inhabit a range of fouling organisms among them being common gastropod mollusks, bivalves and chitons.

Gallery

File:Atrina seminuda (Lamarck, 1819) top.jpg, External view of a bivalve ''Atrina seminuda'' where you can see epibionts associated with this species. File:Atrina seminuda (Lamarck, 1819) inner.jpg, Internal view of a leaflet ''Atrina seminuda''

Commons names

Venezuelan folk tradition on its shores this bivalve is known under several names like so: rompechinchorro, hacha, cocha abanico, papa reina y cucharonCostas de Venezuela: Cucharón, ''Atrina seminuda'' (Lamarck, 1819)
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References

External links

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World Register of Marine Species (Worms): ''Atrina seminuda'' (Lamarck, 1819) AphiaID: 420740

Integrated Taxonómica Informatión System (ITIS): ''Atrina seminuda'' (Lamarck, 1819) Taxonomic Serial No.: 79580

Smithsonian National Museum of Natural History: ''Atrina seminuda''

Biodiversity Heritage Library (BHL): ''Atrina seminuda''
{{Taxonbar, from=Q3016811 Pinnidae Bivalves described in 1819