Long spatula
| Long spatula | ||||||||||||
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| Scientific name | ||||||||||||
| Thracia pubescens | ||||||||||||
| ( Pulteney , 1799) |
The long spatula clam ( Thracia pubescens ) is a type of clam from the family of spatula clams (Thraciidae).
features
The unevenly folded, only moderately inflated housing is up to 90 mm long (according to Poppe and Goto up to 100 mm). The right flap is slightly larger and more arched than the left flap. It is unequal, the vertebrae sit a little behind the midline. The vertebrae are directed slightly backwards. The vertebra of the left valve comes into a position at the base of the vertebra of the right valve. The housing is egg-shaped in outline with a trimmed rear edge. The posterior dorsal margin is straight and slopes down flat to the truncated posterior margin. The anterior dorsal margin is slightly convex and slopes slightly more steeply to the well-rounded anterior margin. The ventral margin is almost straight. A weak keel extends from the vertebra to the posterior end of the ventral margin. Nordsieck gives the following ratios for width, length and thickness: 70 to 45 to 23 mm. The ligament lies outside and inside. The outer ligament is a wide field behind the vertebrae. The inner ligament lies below the outer ligament in a wide, triangular pit. There is a lithodesm in front of the ligament or the ligament pit, but it is often broken off. The anterior sphincter is long and thin, the posterior sphincter is wide and rounded-triangular. The jacket bay is flat and only extends up to about a third of the length of the housing.
The whitish-cream colored shell is thin and fragile. The ornamentation consists of growth lines parallel to the edge. Overall, the surface is finely grained. The grain is particularly noticeable at the rear edge. The periostracum is yellowish to beige. The inner edge of the case is smooth.
Similar species
The long spatula ( Thracia pubescens ) is significantly larger than the granulated spatula ( Thracia villosiuscula ) and the white bean ( Thracia phaseolina ). The inflated spatula ( Thracia convexa ) is significantly shorter and taller. The posterior dorsal margin is concave, the anterior dorsal margin is convex.
Geographical distribution and habitat
The range extends from the southwest coast of the British Isles south to North Africa and Angola . It is also found in the Mediterranean Sea and in the waters around the Canary Islands .
The animals live in muddy, fine sandy, but also gravelly soils from the low water line to about 60 meters water depth.
Taxonomy
The taxon was first described by Richard Pulteney in 1799 as Mya pubescens . In the later edition of the article from 1813, he changed the name to Mya declivis . MolluscaBase considers the taxon to be valid. However, some authors regard it as a synonym for the inflated spatula ( Thracia convexa ). However, this species is significantly shorter and taller. The posterior dorsal margin is concave, the anterior dorsal margin is convex.
Fritz Nordsieck describes the Mediterranean form as Thracia pubescens var. Solida (Chiereghini in Brusina, 1870). It should be much larger than the typical shape.
supporting documents
literature
- Paul Chambers: British Seashells: A Guide for Collectors and Beachcombers. 233 pp. Remember When, Barnsley 2009 ISBN 978-1-84468-051-1 ; 1-8446-8051-7 Preview on Google Books (p. 196)
- 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. 29)
- 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. 159)
- Guido Poppe. Yoshihiro Goto: European Seashells Volume 2 (Scaphopoda, Bivalvia, Cephalopoda) . 221 pp., Verlag Christa Hemmen, Wiesbaden 1993 (2000 unc. Reprint), ISBN 3925919104 (p. 137)
- Peter J. Hayward, John S. Ryland: Handbook of the Marine Fauna of North-West Europe. X + 800 S., University Press, Oxford 2017 ISBN 978-0-19-954944-3 Preview on Google Books (p. 566)
On-line
Individual evidence
- ^ Richard Pulteney: Catalogs of the birds, shells, and some of the more rare plants, of Dorsetshire. From the new and enlarged edition of Mr. Hutchins's history of that county. 1-92 pp., Nichols, London, 1799.
- ^ Richard Pulteney: Catalogs of the Birds, Shells, and Some of the More Rare Plants of Dorsetshire from the new and enlarged edition of Mr. Hutchins's History of that County. 1-110 pp., Nichols, Son & Bentley, London 1813 Online at Google Books (p. 28 as Mya declivis )
- ↑ MolluscaBase: Thracia pubescens (Pulteney, 1799)
- ↑ Marine Species Identification Portal: MJ de Kluijver, SS Ingalsuo & RH de Bruyne: Mollusca of the North Sea
- ↑ Spiridon Brusina: Ipsa Chiereghinii Conchylia: ovvero contribuzione pella malacologia adriatica desunta dal manoscritto Descrizione de'crostacei, de'testacci, e de'pesci che abitano le Lagune e Golfo Veneto, rappresentati in figure, a chiaro-scalluro Abate Stefano Chiereghini Ven. Clodiense. 280 p., Editori della Biblioteca Malacologia, Pisa, 1870 www.archive.org (p. 52/53).
