Nucula hanleyi
| Nucula hanleyi | ||||||||||||
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Nucula hanleyi |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Nucula hanleyi | ||||||||||||
| Winckworth , 1931 |
Nucula hanleyi is a shell - type from the family of nuculidae (Nuculidae).
features
The evenly folded, slightly inflated housing is triangular-egg-shaped in outline; the maximum length is 18 millimeters. It is longer than it is tall, about four-fifths of its length in height. The vertebra is well behind the center at about 15% seen from the rear end. The anterior dorsal margin is very long and moderately convex, the posterior dorsal margin is almost straight and slopes steeply. The transition from the dorsal margin to the ventral margin is angled, the transition from the anterior dorsal margin to the ventral margin is well rounded. The ventral margin is moderately deeply rounded. The lunula is lanceolate with only weakly defined margins and only slightly raised. The area is heart-shaped, slightly protruding with well-defined edges, but hardly raised.
The lock or lock plate is bent at an angle and is therefore divided into a front and a rear part. It consists of a series of uniform teeth and tooth pits (taxodontic lock); there are 22 to 27 teeth at the front and 12 to 14 teeth at the back. The teeth are long and pointed, and they protrude over the tip of the Resilifer. The internal, elongated pear-shaped ligament is opisthodetic and sits in a well-developed resilifer. Another, externally located, thin and barely visible ligament is located in front of the vertebrae.
The ornamentation consists of numerous, very fine and closely spaced, radial lines or fine ribs, which become clearer towards the edge. They intersect with concentric growth strips and somewhat coarse strips of growth interruptions. The inner edge of the case is serrated, the fine teeth correspond to the ends of the fine radial ribs. The periostracum is smooth and has a silky matt surface. It is gray-green to olive-green in color, sometimes dark brown, and orange or red welts, purple-gray lines or ribbons are common. Occasionally, darker concentric bands also occur. The rear end also often bears spots of manganese deposits. The solid shell is whitish and whitish gray, inside pearly colored.
The surface line is entire without indentation. The two sphincters are egg-shaped and about the same size. The muscle impressions in the shell are not clearly pronounced.
Geographical distribution and habitat
The distribution area of the species extends from the Isle of Man south to the Mediterranean . It lives on fine sand consisting of shell fragments and occurs from about 40 meters water depth to about 90 meters depth.
Taxonomy
The taxon was proposed by Sylvanus Hanley in the joint work (together with Edward Forbes ) A history of British Mollusca and their shells as Nucula radiata . This name is preoccupied by Nucula radiata de Kay, 1843 and was replaced in 1931 by Ronald Winckworth with Nucula hanleyi . The World Register of Marine Species does not list synonyms .
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. 4)
- 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. 36)
On-line
Individual evidence
- ^ Edward Forbes, Sylvanus Charles Thorp Hanley: A history of British Mollusca and their shells. Volume 2, 557 pp., London, J. Van Voorst, 1853. [1] (p. 220)
- ↑ Ronald Winckworth: On Nucula nitida, Sowerby. Proceedings of the Malacological Siety of London, 19: 280-281, London 1931 PDF
- ↑ World Register of Marine Species: Nucula hanleyi Winckworth, 1931