Big mussel
| Big mussel | ||||||||||||
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Great blue mussel ( Modiolus modiolus ) |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Modiolus modiolus | ||||||||||||
| ( Linnaeus , 1758) |
The great mussel or horse mussel ( Modiolus modiolus ) is a type of mussel from the family of mussels (Mytilidae). It is the type species of the genus Modiolus .
features
The same-flap, somewhat bulbous housing is elongated-egg-shaped with a curved or angled dorsal edge and a blunt vertebra. The vertebrae are close, but still well before the anterior end. They are inflected and are comparatively far apart. The cases are up to 23 cm long, but mostly only about 13 cm long. The ligament is quite long. The anterior, very small sphincter is located far in front on the front edge, the posterior sphincter is very large. The lock is toothless, the lock edge is smooth. The shell is made up of an inner, aragonitic layer ( mother-of-pearl ), a central, calcitic layer consisting of prismatic structures and an outer organic layer ( periostracum ). The surface line is not booked. In juvenile specimens, the periostracum is hair-shaped. In older animals, the surface is smooth, apart from rough growth lines. The shell is light purple to bluish in color with a thick, dark brown to blackish brown periostracum. The cases are attached to the ground or other specimens of the species with byssus.
Similar species
The large mussel differs in its enormous size from other mussel species in its range or from the bearded mussel ( Modiolus barbatus ).
Geographical distribution and way of life
The species occurs on the coasts of the northern Atlantic and northern Pacific. In the Atlantic, the distribution area extends from the Arctic to Brittany , and on the American east coast to the height of Florida . In the Pacific, in turn, it stretches from the Arctic to California and to Japan . The species is also found in the North Sea and the western Baltic Sea. It occurs there from deep intertidal to 150 m water depth.
The species digs itself up to about halfway into silt or sandy silt and / or attaches itself to coarser particles and stones with the byssus. If living conditions are favorable, it can also form banks; the housings serve other animals as a substrate.
development
The development has so far only been observed under laboratory conditions. The fertilized eggs measured 78 to 90 µm in diameter with an average of 85 µm. The development proceeded via a cilia-covered gastrula to a trochophora . The elongated, almost conical trochophora had an apical flagellum at the larger end . 40 hours after fertilization, the first D-shaped housing (Prodissoconch I) appeared with a length of 105 µm, a height of 90 µm and a (straight) lock line of 90 µm. The straight lock line remained constant in length with further growth (around 100 µm). At a length of 150 to 165 µm, the straight lock line became more indistinct due to the developing vortex. At a length of 230 to 245 µm and after about 13 days, the foot became visible; the larva is now referred to as the Pediveliger. The pigmented eye spots appeared at a housing length of 270 µm. The foot became fully functional after 18 days and with a housing length of 295 µm. After 19 days, the first Pediveliger went over to soil life.
Taxonomy
The taxon was introduced into scientific literature by Carl von Linné in 1758 as Mytilus modiolus . It is the type species of the genus Modiolus Lamarck, 1799 through secondary tautonymy.
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. 227.
- Rudolf Kilias: Lexicon marine mussels and snails. 2nd edition, Verlag Eugen Ulmer, Stuttgart 1997, ISBN 3-8001-7332-8 , p. 191.
- 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. 31.
- Guido Poppe, Yoshihiro Goto: European Seashells Volume 2 (Scaphopoda, Bivalvia, Cephalopoda). 221 p., Verlag Christa Hemmen, Wiesbaden 1993 (2000 unc. Reprint), ISBN 3925919104 , p. 50.
- Rainer Willmann: Mussels and snails of the North and Baltic Seas. 310 pp., Neumann-Neudamm, Melsungen 1989, ISBN 3-7888-0555-2 , p. 104
Individual evidence
- ↑ Elizabeth H. de Schweinitz and Richard A. Lutz: Larval Development of the Northern Horse Mussel, Modiolus modiolus (L.), Including a Comparison with the Larvae of Mytilus edulis L. as an Aid in Planktonic Identification. Biological Bulletin, 150 (3): 348-360, Chicago 1976.
- ^ 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, Holmiae / Stockholm, Salvius, 1758. Online at Göttingen Digitization Center (p. 706 as Mytilus modiolus ).
- ↑ World Register of Marine Species: Modiolus modiolus (Linnaeus, 1758)
