Nucula tumidula
| Nucula tumidula | ||||||||||||
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Nucula tumidula |
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| Scientific name | ||||||||||||
| Nucula tumidula | ||||||||||||
| Malm , 1861 |
Nucula tumidula is a type of mussel from the nut shell family(Nuculidae).
features
The evenly folded, moderately inflated housing is rounded triangular in outline; the maximum length is seven millimeters. It is slightly longer than it is tall, the height reaching about 85% of the length. The thickness of the housing (both flaps) is about two thirds of the housing height. The vertebra is behind the middle at about two thirds to three quarters of the front end. The vertebra is rather flat and not very prominent. The anterior dorsal margin is long, moderately convex and sloping moderately steeply. The front end is very slightly angled or the curve is slightly broken at the transition to the ventral edge. The posterior dorsal margin is straight, the transition to the ventral margin is angled. Front and rear ends are tightly rounded. The ventral margin is deeply rounded. The lanceolate lunula is not raised and the edges are only indistinct. The area is heart-shaped, slightly protruding, but also has only indistinct edges.
The taxodontic lock or lock plate is bent at an angle and has a front and a rear section. There are 11 to 14 teeth in the front section and five to seven teeth in the rear section. The teeth are long and pointed, and they protrude beyond the tip of the Resilifer. The internal ligament is opisthodetic and sits in a well-formed, rounded-triangular resilifer . An externally located ligament sits in front of the vertebrae; it is thin and barely visible.
The ornamentation consists of numerous, very fine, radial lines or fine ribs. They intersect with narrow, but irregularly spaced, concentric growth strips that become clearer towards the edge. The inner edge of the case is serrated, the fine serrations correspond to the ends of the fine radial ribs. The periostracum is smooth and has a slightly shiny surface. It is gray-green to olive-green in color. The solid shell is whitish and whitish gray, inside pearly colored. The periostracum and shell are corroded on the vertebrae.
The surface line is entire and has no indentation. The two sphincters, egg-shaped in cross-section, are about the same size.
Geographical distribution and habitat
The distribution area of the species extends in the eastern North Atlantic from Norway south to the Mediterranean . It lives on muddy soils from about 37 meters water depth to about 2650 meters depth. The main occurrence, however, is 500 meters down to the Bathyal .
Taxonomy
The taxon was set up in 1861 by August Wilhelm Malm in the combination of Nucula tumidula . The World Register of Marine Species lists two synonyms : Nucula pumila Sars, 1851 and Nucula umbonata Seguenza, 1876.
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. 5.
On-line
Individual evidence
- ↑ Ronald Janssen, EM Krylova: Deep-sea fauna of European seas: An annotated species check-list of benthic invertebrates living deeper than 2000 m in the seas bordering Europe. Bivalvia. Invertebrate Zoology, 11 (1): 43-82, 2014 ( PDF ).
- ^ August Wilhelm Malm: Om flere for the Scandinavian Fauna nye Fiske, Krebsdyr og Bløddyr. Förhandlinger vid de Skandinaviske Naturforskeres, 8: 616-624, Copenhagen, 1861 Bayerische Staatsbibliothek digital p. 621.
- ^ World Register of Marine Species: Nucula tumidula Malm, 1861