Stretched Tell Clam
| Stretched Tell Clam | ||||||||||||
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Elongated Tell Clam ( Moerella donacina ) |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Moerella donacina | ||||||||||||
| ( Pennant , 1777) |
The Stretched tellin ( Moerella donacina ) is a shellfish species from the family of tellins (Tellinidae), also in the North Sea occurs.
features
The moderately flattened, almost equally hinged case is 26 millimeters long. The right flap is only slightly more convex than the left flap. The vertebrae are shifted towards the rear end about a third (the length of the case) from the rear end. The vertebrae are small and curled inwards and backwards (opisthogyr). The outline of the housing is elongated egg-shaped with a wedge-shaped pointed rear end. The length / width ratio is about 1.7. The anterior dorsal margin is almost straight and hardly drops off. The front end is broadly rounded. The posterior dorsal margin is straight and slopes steeply towards the posterior end. This is slightly trimmed; the transition from the dorsal margin to the posterior margin is very flat, while the transition from the posterior margin to the ventral margin is clearly angled. The ventral margin is only flatly rounded. The rear edge is slightly curved to the right.
The ligament is a greenish-brown band that extends behind the vertebrae on an inner, wide ridge (nymph) over a third of the posterior dorsal margin. The lock plate is narrow, there are two cardinal teeth in each flap. In the right valve, the posterior cardinal tooth is furrowed longitudinally and bifid, and the anterior cardinal tooth is small. There is also an anterior and posterior lateral tooth. In the left valve, the anterior cardinal tooth is furrowed lengthways and two-pointed, the posterior cardinal tooth is only very weakly developed. The anterior and posterior lateral teeth are only faintly indicated. In the right flap, the base (or inner end) of the anterior lateral tooth extends to the base of the anterior cardinal tooth. The mantle is deeply indented, the bay is almost rectangular. The apex of the mantle bay almost reaches the anterior sphincter muscle. The lower edge of the mantle bay coincides with the ventral mantle edge over almost the entire length. There are two sphincters; the anterior sphincter is slightly longer but narrower than the posterior sphincter.
The shell is thin-walled but quite firm. The surface has only fine strips of growth parallel to the edge at regular intervals. The inside edge of the housing is smooth. The red-brown periostracum is thin and shiny. The color ranges from whitish, cream to yellowish and pink. Radial pink rays emanate from the vortices. The rays are interrupted and can disappear towards the edge of the housing. Occasionally there are also pure white specimens. The inside of the shell is similarly colored. The rays from the outside shimmer through.
The foot is a very strong digging foot. The siphons are very long, flexible and not grown together. The two gills are unequal in size. The mouth lobes are well developed. The edge of the mantle is drawn out into fringed tentacles.
Similar species
The dwarf teller mussel ( Moerella pygmaea ) is smaller and has a shallow mantle bay. The species is ovoid in outline, it lacks the straight ventral margin. In addition, radial color patterns of this type are rare and not as regular.
Geographical distribution, habitat and way of life
The distribution area of the elongated Tell mussel stretches from northern Norway along the coasts of the eastern Atlantic to Ghana and Angola . It is also found in the North Sea, the Mediterranean and the Black Sea . It has also been found in the coastal waters around Madeira , the Azores and the Canary Islands .
It inhabits coarse sandy soils or Schill from below the intertidal zone to about 45 meters water depth (Nordsieck even gives a water depth of 823 meters). Here it lives deeply buried, lying on the side of the left flap and stretches the siphons to the surface of the sediment. With the inflow siphon it picks up organic detritus from the sediment surface.
Taxonomy
The species was set up as Tellina donacina by Carl von Linné as early as 1758 . It is the type species of the genus Moerella P. Fischer, 1887 and is accepted as a valid taxon by the MolluscaBase.
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. 256 as Tellina donacina )
- 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 (p. 26)
- 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. 131, plate 19, Fig. 70.60)
- Guido Poppe. Yoshihiro Goto: European Seashells Volume 2 (Scaphopoda, Bivalvia, Cephalopoda) . 221 p., Verlag Christa Hemmen, Wiesbaden 1993 (2000 unv. Reprint), ISBN 3925919104 (p. 110, plate 19, Fig. 9)
On-line
- Marine Bivalve Shells of the British Isles: Tellina (Moerella) donacina Linnaeus, 1758 (site of the National Museum Wales, Department of Natural Sciences, Cardiff)
- Species Identification Portal: Tellina donacina (Linnaeus, 1758)
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 3)
- ^ 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. 676).
- ↑ MolluscaBase: Moerella donacina (Linnaeus, 1758)
