Plate clam
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Plate tell mussel ( Macomangulus tenuis ) |
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| Macomangulus tenuis | ||||||||||||
| ( da Costa , 1778) |
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The plate tellin ( Macomangulus tenuis ) is a shellfish species from the family of tellins (Tellinidae). The species is also native to the North Sea and the western Baltic Sea and is one of the most common mussel species there.
features
The comparatively small case is slightly unevenly hinged and strongly flattened. It becomes up to 25 millimeters long. The right flap is slightly larger and more arched than the left flap. The rear end is also bent slightly to the right when looking at the case from above. The housing is elongated ovoid in outline with a slightly pointed rear end. The vertebrae are a little behind the midline.
The flat arched anterior dorsal edge is longer than the posterior dorsal edge and slopes down to the broadly rounded anterior end. The posterior, shorter dorsal margin is almost straight and sloping more steeply. It merges with a very flat kink in the very flat rounded to almost straight rear edge. The rear edge merges with the ventral edge at a flat angle. At the transition from the posterior edge to the ventral edge, a clear keel ends from the vertebra. The ventral edge is only slightly curved from the transition to the rear edge to about the midline, then rounded to the front edge. The rear part of the housing is bent slightly to the right. The two flaps only gape slightly and at a short distance at the rear end.
The ligament is a clearly protruding brown band that extends behind the vertebrae on an inner ridge (nymph) to less than a third of the length of the posterior dorsal margin. The lock plate is narrow. There are two cardinal teeth each in the right and left valve. In the left valve, the anterior cardinal tooth is furrowed lengthways and two-pointed, the posterior cardinal tooth is small (er). In the right valve, on the other hand, the posterior cardinal tooth is longitudinally furrowed and two-pointed, and the anterior cardinal tooth is small (er). In the left valve there is only one short, small posterior lateral tooth. In the right valve, on the other hand, there is a short but strong front lateral tooth and a small rear lateral tooth under and behind the nymph. The coat is deeply indented, the coat book is deep and almost rounded rectangular; it almost reaches the anterior sphincter muscle. There are two sphincters.
The shell is thin-walled, but quite firm. It is white, yellowish, orange-red, pink or red, often with darker bands that run parallel to the edge. Inside, the shell is whitish with a yellowish to reddish color in the vertebral area. The surface is provided with fine growth strips parallel to the edge at irregular intervals. The annual interruptions in growth are easy to see. The inside edge of the housing is smooth. The yellowish periostracum is a thin, membrane-like coating and is transparent.
Similar species
The ribbed Tell Mussel ( Fabulina fabula ), which is similar in outline, has diagonal stripes on the right flap.
Geographical distribution and habitat
The distribution area of the plate clam stretches from northern Norway along the coasts of the eastern Atlantic to southern Morocco . The species is also found in the North Sea, the western Baltic Sea, the Mediterranean and the Black Sea . The depth distribution ranges from the lower tidal range to about 20 meters water depth.
The animals lie buried up to 13 cm deep with the left flap facing down on the side in the sediment. It occurs in sandy soils that are heavily exposed to currents. With their long, mobile siphons, they absorb organic detritus from the sediment surface.
Taxonomy
The taxon was established by Emanuel Mendes da Costa in 1778 . It is the type species of the (sub) genus Macomangulus that Fritz Nordsieck proposed in 1969 as a subgenus of Angulus . Nordsieck distinguished three subspecies (with some varieties):
- Angulus (Macomangulus) tenuis tenuis da Costa, 1778 (the nominate subspecies) with the varieties brevior Bucquoy, Dautzenberg & Dollfus, maximus Bucquoy, Dautzenberg & Dollfus and var.minutus Bucquoy, Dautzenberg & Dollfus,
- Angulus (Macomangulus) tenuis exiguus (Poli, 1795) with the varieties major Monterosato and minor Monterosato. The subspecies is slightly smaller than the nominate subspecies, slightly higher, more triangular and slightly more domed.
- Angulus (Macomangulus) tenuis commutatus (Monterosato, 1884). This form is somewhat longer than the nominate subspecies, very small and almost rectangular in shape and with a thin shell.
Depending on the author, the species is assigned to the genus Tellina Linnaeus, 1758 or to the genus Angulus Megerle von Mühlfeld, 1811. The species is not further subdivided in other publications apart from Nordsieck. MolluscaBase now accepts Macomangulus Nordsieck, 1969 as an independent genus.
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. 258 as Tellina tenuis )
- 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. 133)
- Guido Poppe. Yoshihiro Goto: European Seashells Volume 2 (Scaphopoda, Bivalvia, Cephalopoda) . 221 pp., Verlag Christa Hemmen, Wiesbaden 1993 (2000 unc. Reprint), ISBN 3925919104 (p. 112 as Tellina tenuis )
- Rainer Willmann: Mussels of the North and Baltic Seas. 310 p., Neumann-Neudamm, Melsungen 1989 ISBN 3-7888-0555-2 (p. 164 as Tellina (Angulus) tenuis )
On-line
- Marine Bivalve Shells of the British Isles: Tellina tenuis da Costa, 1778 (site of the National Museum Wales, Department of Natural Sciences, Cardiff)
- Marine Species Identification Portal: Tellina tenuis da Costa, 1778
Individual evidence
- ^ Emanuel Mendez da Costa: Historia naturalis testaceorum Britanniæ, or, the British conchology; containing the descriptions and other particulars of natural history of the shells of Great Britain and Ireland: illustrated with figures. In English and French. - Historia naturalis testaceorum Britanniæ, ou, la conchologie Britannique; contenant les descriptions & autres particularités d'histoire naturelle des coquilles de la Grande Bretagne & de l'Irlande: avec figures en taille douce. En anglois & françois. SI-XII, 1-254, London, Millan, White, Emsley & Robson, 1778 Online at www.biodiversitylibrary.org (p. 210)
- ^ Markus Huber: Compendium of Bivalves 2. A full-color guide to the remaining seven families. A systematic listing of 8,500 bivalve species and 10,500 synonyms. 907 S., Hackenheim, ConchBooks 2015 ISBN 978-3939767633
- ↑ MolluscaBase: Macomangulus tenuis (da Costa, 1778)
