''Abra prismatica'' 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 ...

Semelidae The Semelidae are a family of saltwater clams, marine bivalve molluscs in the order Cardiida. Description Members of this family have rounded or oval, elongated shells, much flattened. The two valves are connected by an internal ligament in c ...

. It occurs in the northeastern

Atlantic Ocean 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 ...

, the

North Sea The North Sea lies between Great Britain, Norway, Denmark, Germany, the Netherlands and Belgium. An epeiric sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian S ...

and 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 ...

, where it lives on the seabed, in shallow areas buried in soft sediment.

Description

''Abra prismatica'' grows to a length of about . Each shell valve is fine and brittle, about twice as long as it is wide and oval or fusiform. It is sculptured with fine concentric lines, the chondrophore (pit to which the internal ligament is attached) points to the posterior. On the right valve are two small cardinal teeth in front of the chondrophore, and a single anterior and single posterior lateral teeth behind it. On the left valve there is a single small cardinal tooth and two small anterior and posterior laterals. The valves are shiny white both inside and out.

Distribution

''Abra prismatica'' is found on the coasts of northwest Europe, the

and the

at depths down to about . It is common around the British Isles and in the

. It prefers fine, silty sand, but is also found in mud or gravel.

Ecology

It shares this type of habitat in the North Sea with the amphipod ''

Bathyporeia elegans ''Bathyporeia elegans'' is a species of amphipod crustacean in the genus '' Bathyporeia'' which occurs in the northeastern Atlantic Ocean. It is unpigmented, and grows up to long. Description ''Bathyporeia elegans'' is a translucent, laterally ...

'', various

polychaete Polychaeta () is a paraphyletic class (biology), class of generally marine invertebrate, marine annelid worms, common name, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that ...

worms, the brittlestar '' Amphiura filiformis'' and the

cumacea Cumacea is an order of small marine crustaceans of the superorder Peracarida, occasionally called hooded shrimp or comma shrimp. Their unique appearance and uniform body plan makes them easy to distinguish from other crustaceans. They live in so ...

n crustacean ''

Eudorellopsis deformis ''Eudorellopsis'' is a genus of hooded shrimps within the family Leuconidae. There are currently 9 species assigned to the genus. Species * ''Eudorellopsis biplicata'' * ''Eudorellopsis deformis'' * ''Eudorellopsis derzhavini'' * ''Eudorel ...

''.

References

{{Taxonbar, from=Q3806259 Semelidae Bivalves described in 1808