(Scacchi, 1834)

Description (shell):
Shell brittle, slightly inequivalve, the left valve a little more convex than the right one. Inequilateral beaks behind the midline, directed inwards. Broadly oval in outline, the anterior dorsal margin sloping downwards, slightly rostrate posteriorly. External ligament is a small brown arched band behind the beaks, the internal ligament is in an oblique chondrophore below it. Sculpture of fine concentric lines and faint radiating lines (the latter are frequently worn away). Growth stages are clear. Right valve with two short cardinal teeth and long single anterior and posterior laterals; left valve with one short cardinal tooth and single, weak, anterior and posterior laterals. Anterior adductor scar longer and thinner than the posterior one. Cruciform muscle scars obscure. Pallial sinus deep, its lower border partly confluent with the pallial line. Margin is smooth.

Size:
Up to 19 mm in length.

Colour:
White. Periostracum brown.

Animal:
Foot is large and powerful; two long siphons.

Habitat:
Burrows in soft substrata.

Distribution:
Only in the northern parts of the North Sea (Distr. A. longicallus). It is distributed from the Norwegian Sea, south to the Iberian Peninsula into the Mediterranean, along the Atlantic coast of Morocco and to the Azores.

Kingdom Animalia
Phylum Mollusca
Class Bivalvia
Subclass Heterodonta
Order Veneroida
Family Semelidae
Genus Abra
Species Abra longicallus

Status in World Register of Marine Species

Accepted name: Abra longicallus (Scacchi, 1834)

Scientific synonyms and common names

Tellina longicallus Scacchi, 1834
Erycina longicallis Philippi, 1844
Ligula profundissima Forbes, 1844
Syndosmya tellinella Seguenza G., 1876

Hayward, P.J., Wigham, G.D. & N. Yonow, 1990. Mollusca I: Polyplacophora, Scaphopoda, and Gastropoda. In: The Marine Fauna of the British Isles and North-West Europe. (ed. P.J. Hayward & J.S. Ryland). Clarendon Press, Oxford: 628-730.

Poppe, G.T. & Y. Goto, 1993. European Seashells. Vol. II. 221 pp. Wiesbaden/Verlag Christa Hemmen.

Sars, G.O., 1878. Bidrag til Kundskaben om Norges Arktiske Fauna. I. Mollusca Regionis Arcticae Norvegiae. Oversigt over de i Norges Arktiske Region forekommende Bløddyr. Christiania Universitets program. 466 pp.

Seaward, D.R., 1990. Distribution of the marine molluscs of north west Europe. Nature Conservancy Council.

Tebble, N., 1966. British Bivalve Seashells. 212 pp. Trustees of The British Museum (Natural history). London.

You can continue searching for Abra longicallus on one of these Web sites:

Fauna Europaea (animals) | IOPI (plants) | NCBI (genetic)

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