Sword-shaped scabbard
| Sword-shaped scabbard | ||||||||||||
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Sword- shaped clam ( Ensis ensis ) |
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| Scientific name | ||||||||||||
| Ensis ensis | ||||||||||||
| ( Linnaeus , 1758) |
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The Ensis ensis ( Ensis ensis ), and sword-shaped knife sheath , Curved razor shell (or unspecific only razor clams) called, is a mussel from the family of Pharidae , which is widespread in the Atlantic Ocean and its adjacent seas.
features
The sword-shaped scabbard shell has a very long, narrow, single-sided housing , it is up to 13 cm long and about 1.3 cm high. The length / width ratio is about 8 to 9. The case is always more or less clearly curved. The dorsal and ventral margins run almost parallel. The front end is rounded, the rear end truncated at an angle. The vertebrae lie near the front edge. The front and rear ends gape constantly, due to the muscular foot emerging at the front end and the short siphons at the rear end.
The ligament lies on the outside as a long, narrow brown band behind the vertebrae. The lock has a short, hook-shaped cardinal tooth and a horizontal, elongated cardinal tooth in the right flap; In the left valve there are two cardinal teeth and two posterior, horizontally running, elongated cardinal teeth that sit one above the other. The anterior sphincter is large and drawn out long, the posterior sphincter small and close to the edge of the mantle. This forms a deep and wide sinus at the rear end.
The shell is thin-walled and brittle. The outside of the housing has only growth lines parallel to the edge. The color of the housing is divided diagonally from the vertebra (front) to the lower edge of the rear end. The upper diagonal field is whitish, the lower diagonal field is brownish. The periostracum is greenish-yellow to dark green in color and shiny. The inside edge of the case is smooth. The inside is whitish, often tinged blue or purple.
Similar species
All species of the Ensis genus (e.g. American sheath clams ) are very similar and differ only slightly in terms of color, size and proportions of the housing.
Geographical distribution, habitat and way of life
The species occurs in the coastal waters of the North Atlantic from Norway to Morocco. The species is also widespread in the North Sea and the western Baltic Sea, as well as in the Mediterranean.
The animals live vertically buried in the loose, sandy-silty sediment with the front end down. The animal anchors itself in the sediment with its muscular foot and can quickly withdraw if disturbed. The species lives in water depths from the intertidal zone to about 80 meters.
The animals are of separate sex. The eggs are released into the open water, where they are fertilized. The development takes place via a Veliger larva, which lives in the plankton for about a month before it metamorphoses and changes to soil life. They can live up to 10 years old and are sexually mature after 3 years.
Taxonomy
The species was first described as Solen ensis by Carl von Linné . The species is now generally recognized as belonging to the genus Ensis Schumacher, 1817.
supporting documents
literature
- S. Peter Dance, Rudo von Cosel (arrangement of the German edition): The great book of sea shells. 304 p., Verlag Eugen Ulmer, Stuttgart, 1977 ISBN 3-8001-7000-0 (p. 254)
- 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 3-925919-10-4 (p. 106)
- Rainer Willmann: Mussels of the North and Baltic Seas. 310 p., Neumann-Neudamm, Melsungen 1989 ISBN 3-7888-0555-2 (p. 72)
- Paul Chambers (with figures from George Sowerby): British Seashells: A Guide for Collectors and Beachcombers. 233 pp. Remember When, Barnsley Yorkshire, 2009 ISBN 978-1-84468-051-1 (p. 166)
On-line
- Marine Bivalve Shells of the British Isles: Ensis ensis (Linnaeus, 1758) (site of the National Museum Wales, Department of Natural Sciences, Cardiff)
- Marine Species Identification Portal: Ensis ensis (Linné, 1758)
Individual evidence
- ^ Carl von Linné: Systema naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata. Pp. 1-824, Holmia / Stockholm, Salvius, 1758. Online at www.biodiversitylibrary.org (p. 672).
- ↑ MolluscaBase: Ensis ensis (Linnaeus, 1791)
annotation
- ↑ The naming of the horizontal teeth is not uniform in the literature. In some publications they are referred to as main / cardinal teeth, in other publications as side / lateral teeth.
