Gastrana fragilis
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Gastrana fragilis |
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| ( Linnaeus , 1758) |
Gastrana fragilis is a shellfish species from the family of tellins (Tellinidae), also in the North Sea occurs.
features
The same-folding, non-inflated housing is up to 45 millimeters long. It is broad-ovoid to slightly rounded-triangular in outline with a wedge-shaped elongated rear end. It is slightly unequal, the vertebrae are slightly shifted towards the front end. They taper to a point and are curled up almost perpendicular to the longitudinal axis of the housing (orthogyr). The posterior and anterior dorsal margins initially drop towards the posterior or anterior end and form an angle of about 120 °. While the front edge is widely rounded, the rear edge is somewhat elongated and truncated at an angle. The rear end is thus much more rounded (than the front end), and viewed in the overall habitus, the housing is slightly "beaked". The ventral margin is well rounded. The case gapes a little at the front and rear. A weak keel and a wide, weak sine (more towards the middle of the case) extend from the vertebra to the rear edge of the case.
The dark brown ligament , located on an inner ridge, extends behind the vertebrae for about a third of the length of the posterior dorsal margin. There is no lunula . The area is lanceolate, concave and covered by the ligament. There are two cardinal teeth in each of the two valves, lateral teeth are missing. In the left valve, the anterior cardinal tooth is hook-shaped, grooved and bilobed, the posterior small. In the right valve there are two cardinal teeth that diverge strongly downwards. The coat is deeply indented tongue-shaped. At the ventral edge, the mantle edge and the ventral edge of the mantle bay run together for about a third of the distance. The bay extends to about a third of the length of the housing. There are two generally egg-shaped or elongated elliptical sphincters, the front of which is slightly larger.
The thin-walled and fragile shell is whitish, in the vertebral area light orange. Inside, the bowl is shiny white with an orange tint. The ornamentation consists of fine ribs parallel to the edge and indentations at somewhat irregular intervals as well as very fine radial lines that are mostly limited to the center of the case and are only visible under the microscope . The inner edge of the case is smooth. The beige-colored periostracum is a thin coating on the shell.
Geographical distribution and habitat
Gastrana fragilis is native from Norway to the Iberian Peninsula and Morocco, as well as in the Mediterranean , the Black Sea and the waters around the Canary Islands . According to Nordsieck, it is also said to occur off Greenland and in the Caspian Sea .
It lives buried in muddy, muddy-sandy or muddy-gravelly soils mainly in the tidal area , often also in harbors.
Taxonomy
The taxon was founded in 1758 by Carl von Linné . It is the type species of the genus Gastrana Schumacher, 1817. Generic and species taxons are treated as valid taxa by the MolluscaBase.
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. 128)
- Guido Poppe. Yoshihiro Goto: European Seashells Volume 2 (Scaphopoda, Bivalvia, Cephalopoda) . 221 pp., Verlag Christa Hemmen, Wiesbaden 1993 (2000 unc. Reprint), ISBN 3925919104 (p. 109)
On-line
Individual evidence
- ↑ George Brettingham Sowerby II : Illustrated index of British shells. containing figures of all the recent species, with names and other information. XV S., XXIV plate. London, Simpkin, Marshall & Co., 1859 Online at www.biodiversitylibrary.org (plate 2)
- ^ 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. 674).
- ↑ MolluscaBase: Gastrana fragilis (Linnaeus, 1758)
