Shellfish
| Shellfish | ||||||||||||
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European shellfish ( Ensis siliqua ) |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Ensis siliqua | ||||||||||||
| ( Linnaeus , 1758) |
The pods clam ( Ensis siliqua ), and Large razor clams or pods shaped razor clams called, is a mussel from the family of Pharidae . It is rather rare in the North Sea .
features
The shell of the shell is very long, narrow and has the same flaps ; it is up to 20 cm long, the height (with a length of 20 cm) 2.8 cm and the thickness 1 cm. This results in a length to height ratio of about 7. The dorsal and ventral margins run almost parallel, the dorsal margin is almost straight, while the ventral margin is slightly curved. The case is also slightly higher at the back than at the front. Front and rear ends are flatly rounded to almost straight and sloping slightly at an angle. It is strongly asymmetrical, the small vertebrae are near the front end. The front and rear ends cannot be closed completely, they constantly gape. At the front end the muscular foot emerges, at the rear end the relatively short siphons . The rear opening is egg-shaped in cross section.
The externally located ligament is a long, narrow, brown to black band behind the vertebrae. The lock has an elongated cardinal tooth and a horizontal, elongated, posterior lateral tooth in the right flap. In the left valve there are two peg-shaped cardinal teeth and two rear, elongated lateral teeth, one above the other. The jacket bay is U-shaped. There are two sphincters. The anterior sphincter is elongated, lies dorsal and extends beyond the ligament. The posterior sphincter, on the other hand, is small and rounded and detached from the mantle. The anterior sphincter is longer than the ligament. The distance between the anterior sphincter scar from the dorsal edge of the housing corresponds approximately to the distance between the posterior sphincter and the ventral edge of the housing.
The shell is comparatively thin and brittle. The color varies from off-white, off-white to gray with some reddish brown, pale purple, or pale pink spots and bands. The outside of the housing shows growth lines parallel to the edge and growth interruptions (coarser lines). The glossy, greenish to yellowish brown periostracum becomes darker and brownish towards the edges. Inside, the shell is whitish with a bluish or purple tint. The inside edge of the housing is smooth.
The soft body is gray-brown with a yellowish, tongue-shaped foot. The siphons are short and overgrown; the openings are filled with fringed filaments. At the base of the filaments there are light-sensitive pigment spots in small pits, which are very sensitive to light-dark and movement. Shading causes the animals to withdraw into the sediment.
Similar species
In Ensis minor , the posterior sphincter is closer to the edge of the housing than the anterior sphincter is closer to the dorsal edge of the housing.
Geographical distribution and habitat
The mussel is common from Norway to Morocco and the Mediterranean . It lives buried in fine sand or silty sand from the intertidal zone to a depth of around 70 m.
The animals dig in fine sand or silty sand. In the living position they stick vertically with the front end down in the sediment. When the water is covered, the animals always stay close to the sediment surface. At low tide, however, they can retreat up to half a meter into the sediment.
Reproduction
The animals are of separate sex. They released their sex products into the open water in the vicinity of Plymouth (southern England) in March / April. The eggs are quite small at 70 µm. The development takes place via a Veliger larva, which lives in the plankton for up to a month before it changes to soil life. The animals become sexually mature at around three years of age and can live up to 10 years.
Taxonomy
The species was first described as Solen siliqua by Carl von Linné . The species is now generally recognized as belonging to the genus Ensis Schumacher, 1817.
supporting documents
literature
- Fritz Nordsieck : The European sea shells (Bivalvia). From the Arctic Ocean to Cape Verde, the Mediterranean Sea and the Black Sea. 256 p., Gustav Fischer Verlag, Stuttgart 1969 (p. 145/6)
- Guido Poppe. Yoshihiro Goto: European Seashells Volume 2 (Scaphopoda, Bivalvia, Cephalopoda) . 221 pp., Verlag Christa Hemmen, Wiesbaden 1993 (2000 unc. Reprint), ISBN 3925919104 (p. 107)
- Rainer Willmann: Mussels of the North and Baltic Seas. 310 p., Neumann-Neudamm, Melsungen 1989 ISBN 3-7888-0555-2 (p. 170)
On-line
- Marine Bivalve Shells of the British Isles: Ensis siliqua (Linnaeus, 1758) (site of the National Museum Wales, Department of Natural Sciences, Cardiff)
- Marine Species Identification Portal: Ensis siliqua (Linné, 1758)
Individual evidence
- ↑ List of trade names for fishery and aquaculture products, taking into account the current Federal Gazette announcements of: a) 83rd amendment to the announcement on trade names from November 15, 2016 b) 94th definition of provisional trade names from March 1, 2017 PDF ( Page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
- ^ Theodor CH Cole: Dictionary of Invertebrates / Dictionary of Invertebrates: Latin-German-English. Springer Spektrum, Berlin 2017, ISBN 978-3-662-52869-3 , p. 46. Preview on Google Books
- ↑ Marie V. Lebour: Notes on the breeding of some lamellibranchs from Plymouth and Their larvae. Journal of the Marine Biological Association of the United Kingdom,: 23 (1): 119-144, 1938. PDF
- ^ 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 siliqua (Linnaeus, 1758)
