Elliptical trough clam
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Elliptical trough clam ( Spisula elliptica ) |
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| Spisula elliptica | ||||||||||||
| ( Brown , 1827) |
The elliptical trough clam ( Spisula elliptica ) is a species of clam from the family of trough clams (Mactridae) that is widespread in the North Atlantic .
features
The evenly folded, slightly inflated, non-gaping housing is up to 32 millimeters long. It is egg-shaped to rounded-triangular in outline and slightly unequal. The vertebrae sit immediately in front of the center line, based on the length of the case. The anterior dorsal margin is slightly shorter than the posterior dorsal margin. The anterior dorsal margin is broadly rounded, the transition to the anterior margin is slightly angled. The posterior dorsal margin is almost straight to slightly convex. The transition to the rear edge is also slightly angled, but sits a little lower than the front transition. The ventral margin is well rounded. The anterior dorsal field has a slightly protruding lunula . The external, dark brown ligament is small and thin. The internal part sits in a triangular pit. The lock has two cardinal teeth in the right flap and two anterior and posterior lateral teeth. In the left flap there are three cardinal teeth, of which the two front teeth form an inverted V-shaped extension that protrudes beyond the actual lock plate. The third posterior cardinal tooth is small and fragile and is therefore often broken off. There are also anterior and posterior lateral teeth. The upper and lower surfaces of the lateral teeth in the left valve are notched. The inner sides of the lateral teeth are notched in the right flap. The surface line is indented, the bay reaches the rear end of the chondrophor.
The whitish to cream-colored skin is firm but brittle. The ornamentation consists of concentric lines. The inside edge of the case is smooth. The thin periostracum is pale brown to dark brown.
Geographical distribution and habitat
The elliptical trough clam occurs from Iceland and the Barents Sea along the coasts of the Eastern Atlantic to Gibraltar and the western Mediterranean . It also penetrates into the North Sea .
It lives buried in silty, sandy and gravelly soils from about 20 meters to 200 meters water depth.
Taxonomy
The species was established in 1827 by Thomas Brown under the original binomial Mactra elliptica . It is now generally accepted as belonging to the genus Spisula Gray, 1837.
supporting documents
literature
- Fritz Gosselck, Alexander Darr, Jürgen HJ Jungbluth, Michael Zettler: common names for mollusks of the sea and brackish water in Germany. Mollusca, 27 (1): 3-32, 2009 PDF
- Fritz Nordsieck: The European sea shells (Bivalvia). From the Arctic Ocean to Cape Verde, the Mediterranean Sea and the Black Sea. 256 pages, Gustav Fischer Verlag, Stuttgart 1969
- Guido Poppe. Yoshihiro Goto: European Seashells Volume 2 (Scaphopoda, Bivalvia, Cephalopoda) . 221 pp., Verlag Christa Hemmen, Wiesbaden 1993 (2000 unc. Reprint), ISBN 3925919104 (pp. 101/2)
- Rainer Willmann: Mussels of the North and Baltic Seas. 310 p., Neumann-Neudamm, Melsungen 1989 ISBN 3-7888-0555-2 (p. 148)
On-line
Individual evidence
- ^ Thomas Brown: Illustrations of conchology of Great Britain and Ireland. Drawn from nature. SI-IV, 1-65, Pl. 1-52, Edinburgh, Lizars, 1827 [online at www.biodiversitylibrary.org] (p.).
- ↑ MolluscaBase: Spisula elliptica (Brown, 1827)
