Otter clam
| Otter clam | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Otter clam ( Lutraria lutraria ) |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Lutraria lutraria | ||||||||||||
| ( Linnaeus , 1758) |
The otter mussel ( Lutraria lutraria ) is a species of mussel from the family of trough mussels (Mactridae) that is widespread in the North Atlantic .
features
The same-folding, non-inflated housing reaches a length of up to 13 cm. The ratio of length to max. Height is about 2. It is moderately unequal, the vertebrae sit in front of the midline in relation to the length of the case (about a third of the total length from the front end). The outline of the case is elliptical. The posterior dorsal margin is long and straight, and slopes gently towards the rounded posterior end. The anterior dorsal margin is shorter, very flat convex and sloping a little steeper towards the anterior end. The front end is rounded a little further. The ventral margin has an almost straight area in the middle. The closed housing gapes at the front and rear end, so there is only a short area on the ventral edge where the two valves meet.
The ligament is external and internal. The external ligament behind the vertebra is a small, dark brown, deeply sunk band. The internal ligament sits in a large, spoon-shaped process (chondrophor). The top of the pit sits just below the vertebrae. The left valve shows two cardinal teeth that form a V-shaped structure just in front of the ligamentous pit. There is also a very small, thin lateral number between the ligament pit and the two large cardinal teeth, which breaks off very easily. In addition, there are two small, lamellar posterior teeth close to the edge of the case and running parallel to it. Two cardinal teeth are formed in the right valve and a lamellar posterior lateral tooth. The mantle is deep and deeply indented at the back, the apex of the bay is approximately below the eddy. At the ventral edge, the mantle edge and the ventral part of the mantle bay are separated or do not coincide. There are two sphincter muscles of approximately the same size.
The whitish skin is thick-walled, firm but brittle. The ornamentation consists of concentric lines and pits. The inner edge of the case is smooth. The periostracum is scaly and olive-brown.
Geographical distribution, habitat and way of life
The distribution area of the species extends from Northern Norway along the coastal waters of the Eastern Atlantic to West Africa ( Senegal ). It also penetrates into the North and Baltic Seas and the Mediterranean . It lives up to 35 cm deep buried or digging in sandy, sandy, silty and gravelly soils from the tidal range to about 100 meters water depth.
Taxonomy
The taxon was set up by Carl von Linné as Mya lutraria . It is the type species of the genus Lutraria Lamarck, 1799.
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. 252)
- 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. 143)
- Guido Poppe and Yoshihiro Goto: European Seashells Volume 2 (Scaphopoda, Bivalvia, Cephalopoda) . 221 p., Verlag Christa Hemmen, Wiesbaden 1993 (2000 unc. Reprint), ISBN 3925919104 (p. 100)
On-line
- Marine Bivalve Shells of the British Isles: Lutraria lutraria (Linnaeus, 1758) (site of the National Museum Wales, Department of Natural Sciences, Cardiff)
- Lutraria lutraria (Linné, 1758) Marine Species Identification Portal
Individual evidence
- ^ 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. 670).
- ↑ MolluscaBase: Lutraria lutraria (Linnaeus, 1758)
