Bearded ark shell
| Bearded ark shell | ||||||||||||
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Bearded ark mussel ( Barbatia barbata ) |
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| Scientific name | ||||||||||||
| Barbatia barbata | ||||||||||||
| ( Linnaeus , 1758) |
The bearded ark clam ( barbatia barbata ) is a shell - type from the family of ark shells (Arcidae) from the order of Arcida .
features
The housing, which has the same flap, is approximately oblong trapezoidal with a maximum length of 53 mm (up to 70 mm). The rear part of the housing is clearly drawn out; Overall, the case is about twice as long as it is high. It is moderately bulbous, the height / thickness index is almost 1.5. The vertebra sits about a quarter (of the total length) from the front end. The flat, broad vertebrae protrude above the almost straight, moderately long dorsal margin. This only takes up about half of the total housing length.
The straight to slightly concave rear edge falls flat, the transition to the ventral edge is tightly rounded. The anterior margin is moderately convex and slopes steeply from the dorsal margin. The ventral margin is slightly to almost straight curved. The front area of the ventral margin gapes for the passage of the byssus even when the housing is closed.
The lock plate is curved, the lock is taxodont. The teeth become larger towards the edge and are increasingly tilted outwards. The middle teeth are stunted. The ligament is elongated and narrow.
The shell is relatively thick and not translucent. The ornamentation consists of tightly standing, radial ribs that are interrupted by growth stops. Every fourth to sixth rib can be made somewhat stronger, especially on the edge of the housing. The periostracum is dark brown and elongated into bristles or hair, especially in the rear and front housing parts. That gave her the name of the bearded one .
The two sphincters are not the same, the anterior sphincter is slightly smaller than the posterior sphincter.
Similar species
Compared to the Noahs Ark Shell , the case is much slimmer, the height-width index is almost 1.5, while the Noahs Ark Shell is much more bulbous with an H / D index of 0.8. The angular ark shell ( Arca imbricata ) is rounded-rectangular in outline.
Geographical distribution and habitat
The bearded ark shell occurs in the eastern Atlantic from Portugal to the Cape Verde Islands . The main distribution area is the Mediterranean . It lives here attached with byssus threads in crevices, on stones or horn corals . It occurs from the tidal range to a depth of around 280 meters. They feed on plankton , which is filtered from the water, but also on detritus and microorganisms, which they ingest from the surface of the sediment with the help of mouth rags.
Taxonomy
The taxon was set up in 1758 by Carl von Linné as Arca barbata . It is the type of the genus Barbatia Gray, 1842. The World Register of Marine Species lists the following synonyms : Arca barbata var. Contracta Bucquoy, Dautzenberg & Dollfus, 1891, Arca barbata var. Elongata Bucquoy, Dautzenberg & Dollfus, 1891, Arca barbata var . expansa Bucquoy, Dautzenberg & Dollfus, 1891, Arca bonnaniana Risso, 1826, Arca cylindrica Wood, 1828, Arca magellanica Bruguière, 1789, Arca reticulata Turton, 1819 and Barbatia eximia Dunker, 1866.
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. 224)
- Rosina Fechter, Gerhard Falkner: Mollusks. 287 p., Mosaik-Verlag, Munich 1990 (Steinbach's Nature Guide 10), ISBN 3-570-03414-3 (p. 76/7)
- 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. 20/1)
- 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. 43)
Individual evidence
- ↑ Rudolf Kilias: Lexicon marine mussels and snails. 2nd edition, 340 p., Verlag Eugen Ulmer, Stuttgart 1997, ISBN 3-8001-7332-8 (p. 44).
- ^ 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. 698 as Ostrea opercularis ).
- ^ A b World Register of Marine Species: Aequipecten opercularis (Linnaeus, 1758) .
