Abra prismatica

Abra prismatica
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Bivalvia
Order:	Cardiida
Superfamily:	Tellinoidea
Family:	Semelidae
Genus:	Abra
Species:	A. prismatica
Binomial name
Abra prismatica (Montagu, 1808)
Synonyms
Abra fragilis Risso, 1826 Abra milaschevichi Nevesskaja, 1963 Erycina aradae Biondi, 1859 Ligula prismatica Montagu, 1808 Psammotaea striata O. G. Costa, 1830 Syndesmya fragilis Milaschewitsch, 1916

Abra prismatica is a species of bivalve mollusc in the family Semelidae. It occurs in the northeastern Atlantic Ocean, the North Sea and the Mediterranean Sea, where it lives on the seabed, in shallow areas buried in soft sediment.

Description

Abra prismatica grows to a length of about 13 cm (5 in). 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 North Sea and the Mediterranean Sea at depths down to about 100 m (330 ft). It is common around the British Isles and in the North Sea. 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, various polychaete worms, the brittlestar Amphiura filiformis and the cumacean crustacean Eudorellopsis deformis.