Thick-shelled Tell Clam

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Thick-shelled Tell Clam
Thick-shelled Tell Clam (Arcopagia crassa)

Thick-shelled Tell Clam ( Arcopagia crassa )

Systematics
Order : Cardiida
Superfamily : Tellinoidea
Family : Tell clams (Tellinidae)
Subfamily : Arcopagiinae
Genre : Arcopagia
Type : Thick-shelled Tell Clam
Scientific name
Arcopagia crassa
( Pennant , 1777)
Arcopagia crassa (Pennant, 1777) (from GB Sowerby II, 1859: plate 3, fig. 5)

The Thick-shelled tellin ( Arcopagia crassa ) is a bivalve mollusc of the family of tellins (Tellinidae), also in the North Sea is native.

features

The slightly unevenly hinged, non-inflated housing reaches a length of 65 millimeters. The right flap is more arched than the left flap. It is broadly ovoid to almost circular in outline. The vertebrae sit a little behind the middle. The posterior and anterior dorsal margin are only slightly convexly curved. The anterior, slightly longer anterior dorsal margin falls off slightly flatter to the well-rounded anterior margin. The slightly shorter, posterior dorsal margin starts slightly higher and slopes down a little steeper to the rounded posterior end. The ventral margin is well rounded. There is a small dent in the back of the ventral margin.

The lunula is a chestnut brown or reddish brown colored depression with fine radial furrows. An area is not developed. The ligament is a dark brown band that extends behind the vertebrae on an internal ridge for half the length of the posterior dorsal margin. There are two cardinal teeth in each valve. In the left valve, the anterior cardinal tooth is furrowed and bilobed, the posterior small. In the right valve, on the other hand, the posterior cardinal tooth is furrowed and two-pointed and the anterior cardinal tooth is small. There is also a small anterior and a small posterior lateral tooth in both valves. The coat is deeply indented and tongue-shaped. The bay is directed obliquely upwards towards the anterior sphincter muscle and extends beyond the midline. There are two sphincters, the front one of which is slightly longer.

The dirty white bowl is thick-walled and firm. The surface is provided with fairly regular fine ribs and depressions parallel to the edge. The annual interruptions in growth are easy to see. They intersect with much finer radial lines that are only visible under the microscope; this makes the fine ribs parallel to the edge appear slightly curled. The edge of the housing is smooth without notches or the like. The periostracum is a thin, matt-glossy coating of yellow-brown color. The vertebrae are often tinged orange-red or brown-red; rays of the same color often emanate from the vortices and extend to the edge of the housing. The inside is also often tinted orange-red, especially in the vertebral area, the tint can extend to the edge of the case.

Geographical distribution and habitat

The distribution area of ​​the species extends from northern Norway to Senegal . It is also found in the North Sea and the western Mediterranean .

It lives in sandy soils, as well as coarse-sand and shingle soils from around 20 meters to 150 meters of water depth.

Taxonomy

The taxon was set up in 1777 by Thomas Pennant as Tellina crassa . It is the type species of the genus Arcopagia Brown, 1827. The genus and species are recognized by the MolluscaBase as valid taxa.

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. 255 as Tellina crassa )
  • 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)
  • Rudolf Kilias: Lexicon marine mussels and snails. 2nd edition, 340 pp., Verlag Eugen Ulmer, Stuttgart 1997 ISBN 3-8001-7332-8 (p. 303)
  • 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. 127)
  • 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)
  • Rainer Willmann: Mussels of the North and Baltic Seas. 310 p., Neumann-Neudamm, Melsungen 1989 ISBN 3-7888-0555-2 (p. 160/1)

On-line

Individual evidence

  1. ↑ 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)
  2. ^ Thomas Pennant: British Zoology. Vol. IV. Crustacea. Mollusca. Testacea. Pp. III-VIII, 1-154, Plates I-XCII (= 1-93), London, White, 1777 Online at www.biodiversitylibrary.org (p. 87)
  3. ↑ MolluscaBase: Arcopagia crassa (Pennant, 1777)

Web links

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