Bathyarca frielei

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Bathyarca frielei
Systematics
Order : Arcida
Superfamily : Arcoidea
Family : Ark clams (Arcidae)
Subfamily : Bathyarcinae
Genre : Bathyarca
Type : Bathyarca frielei
Scientific name
Bathyarca frielei
( Friele , 1877)

Bathyarca frielei is a mussel species from the family of ark clams (Arcidae) in the order Arcida .

features

The slightly unevenly hinged, non-inflated housing has a rounded, wedge-shaped outline. The left flap is slightly larger than the right flap, which is practically in the left flap. The length of the adult housing is only about five millimeters. The case is only slightly longer than it is tall (L / H index = 1.3). The ratio of length to thickness (both keys) (L / D index) is 2. The rear part of the housing is also only slightly extended. The lower vertebra sits just in front of the middle of the total dorsal length, at about a third from the anterior margin. The dorsal margin is long and straight; seen from above there is only a narrow dorsal field. At the posterior end, the dorsal margin is broadly rounded and merges with the moderately curved posterior margin. The anterior dorsal margin, on the other hand, merges into the anterior margin in a tightly rounded manner. The rear and front edges merge into the ventral edge without any noticeable change in curvature. The indentation for the byssus is barely visible. The inner edge of the case of the larger left flap has weak serrations that correlate with the radial ribs. The inner edge of the smaller right flap, on the other hand, is smooth.

The lock is taxodont , the lock plate is curved. The five very weakly developed teeth in the front part are crooked, the up to five teeth in the rear part are arranged approximately parallel to the dorsal margin.

The whitish translucent shell is thin and fragile. The fine and weak ornamentation consists of fine radial and tightly standing lines that are somewhat stronger than the fine concentric growth strips. The ornamentation is somewhat more pronounced on the smaller right flap. The periostracum is light straw-colored and drawn out into very short bristles, which are essentially arranged radially. The inner edge of the case is slightly serrated on the larger, left flap, but smooth on the smaller, right flap.

The muscle attachment points can only be seen indistinctly. Of the two sphincters, the anterior sphincter is slightly smaller than the posterior sphincter. The surface line is entire without indentation.

Geographical distribution, way of life and habitat

The distribution area of Bathyarca frielei extends in the eastern North Atlantic from the Arctic to the height of North Africa. It also penetrates into the Mediterranean. It occurs there in somewhat coarser sediments at a depth of between 18 and 2814 meters.

Taxonomy

The taxon was first described by Herman Friele as Arca frielei . Another description by the same author is from 1901. He wrote the name John Gwyn Jeffreys , although it is not clear from the first description what contribution Jeffreys and (whether anything at all) made to the first description. The first author is therefore Herman Friele. The species is now part of the genus Bathyarca Kobelt, 1891. The World Register of Marine Species only lists one synonym : Arca pectunculoides crenulata Verrill, 1882.

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. 22)

On-line

Individual evidence

  1. ↑ Serge Gofas 1, Carmen Salas 1, José Luis Rueda 2, Jesús Canoura 3, Carlos Farias 3, Juan Gil: Mollusca from a species-rich deep-water Leptometra community in the Alboran Sea. Scientia Marina, 78 (4): 000-000, 2014 Barcelona doi : 10.3989 / scimar.04097.27A
  2. ↑ James H. Gamber, David L. Clark: Distribution of Microscopic Molluscs Echinoderms and Sponges in the Central Arctic Ocean. Micropaleontology, 24 (4): 422-431, 1978
  3. ↑ Herman Friele: Preliminary Report on Mollusca from the Norwegian North Atlantic Expedition 1876. Nyt magazin for naturvidenskaberne, 23 (3): 2-10, Christiania / Oslo, 1877 Online at www.biodiversitylibrary.org (p. 2)
  4. ^ Herman Friele: Zoologi. Mollusca III. Pelecypoda. In: The Norwegian North-Atlantic Expedition 1876-1878 , pp. 6–48, Christiania / Oslo, 1901 Online at www.biodiversitylibrary.org (p. 20 as Arca frielei )
  5. ↑ a b World Register of Marine Species: Bathyarca frielei (Friele, 1877)

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