Latticed crenella
| Latticed crenella | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Crenella decussata | ||||||||||||
| ( Montagu , 1808) |
The gridded crenella ( crenella decussata ) is a shell - type from the family of mussels (Mytilidae).
features
The comparatively small housings are transversely egg-shaped. They measure 1.5 to 3 millimeters in length and 1.4 millimeters in width. The vertebra protrudes beyond the front end. The surface has approx. 50 radial ribs that form a grid-like pattern with the concentric strips (approx. 40). The radial ribs split on the edge of the housing, the edge of the housing is notched. The outside sculpture is imprinted on the inside. The lock edge is wide and striated across. The ligament is sunk, the foot thickens. The skin is firm and creamy white, and covered with a light to dark brown periostracum .
The almost equilateral larval case is D-shaped with a straight dorsal margin and an almost semicircular ventral margin; only the front end is slightly more blunt. The metamorphosis takes place with a housing length of 190 to 200 µm. No vertebrae have formed yet. The outside is finely granulated; no growth lines are visible. The very narrow provinculum (= preliminary stage of the actual lock) has eight to ten teeth at the front and back; in the middle the teeth are very indistinct. The ligament sits approximately in the middle, but slightly shifted towards the rear end.
Similar species
The striking D-shaped larval case of the latticed crenella ( Crenella decussata ) is very similar to the larval case of Septifer keenae , and bears little resemblance to the larval cases of Mytilus and Modiolus species, which are egg-shaped and have very distinct vertebrae.
Geographical distribution and way of life
Crenella decussata is common in the northern North Atlantic and North Pacific. In the Atlantic, the distribution area extends from the Arctic to Morocco and the Caribbean, in the Pacific from the Arctic to Japan. In the eastern Atlantic, it also penetrates the North and western Baltic Seas.
It lives buried in the uppermost layers of fine or silty sandy soils. It lives there from about 4 meters water depth to about 200 meters water depth. In the North Sea it was found to a depth of almost 70 m, in the Baltic Sea from 20 to 30 meters.
development
The females lay the eggs, which are relatively rich in yolk, in piles in August. Due to the yolk-rich development, the pelagic stage is only briefly before the young mussel changes to bottom life.
Taxonomy
The taxon was established in 1808 by George Montagu as Mytilus decussatus . It is de facto type species of the genus Crenella Brown, 1827, since its formal type species Crenella elliptica Brown, 1827 is a younger synonym of Crenella decussata .
supporting documents
literature
- 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. 30)
- Guido Poppe and Yoshihiro Goto: European Seashells Volume 2 (Scaphopoda, Bivalvia, Cephalopoda) . 221 pp., Verlag Christa Hemmen, Wiesbaden 1993 (2000 unc. Reprint), ISBN 3925919104 (p. 48)
- Rainer Willmann: Mussels and snails of the North and Baltic Seas. 310 pp., Neumann-Neudamm, Melsungen 1989, ISBN 3-7888-0555-2 (p. 100)
Individual evidence
- ↑ Fritz Gosselck, Alexander Darr, Jürgen HJ Jungbluth, Michael Zettler: Trivial names for mollusks of the sea and brackish water in Germany. Mollusca, 27 (1): 3-32, 2009 PDF
- ↑ a b c Olga Ya. Semenikhina, Natalya K. Kolotukhina, George A. Evseev: Morphology of larvae of the family Mytilidae (Bivalvia) from the north-western part of the Sea of Japan. Journal of the Marine Biological Association of the United Kingdom, 88 (2): 331-339, 2008 doi : 10.1017 / S002531540800065
- ↑ George Montagu: Supplement to Testacea Britannica. IV, pp. 1–183, plates 17–30, London, White, 1808. Online (p. 69, as Mytilus decussatus )
- ↑ World Register of Marine Species: Crenella decussata (Montagu, 1808)
annotation
- ↑ Since some authors also orient the case with the vertebra upwards, the outline is also described as egg-shaped and higher than broad.
