Rocellaria dubia
| Rocellaria dubia | ||||||||||||
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![Rocellaria dubia, housing and secondary tube (from GB Sowerby II, 1859: Plate 1, Fig. 14 [1])](https://de.wikipedia.org/wiki/Datei:GBSowerbyII_pl1_fig14_Rocellaria_dubia.png)
Rocellaria dubia , housing and secondary tube (from GB Sowerby II, 1859: plate 1, fig. 14) |
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| Scientific name | ||||||||||||
| Rocellaria dubia | ||||||||||||
| ( Pennant , 1777) |
Rocellaria dubia is a type of mussel from the family of bored clams (Gastrochaenidae). She drills chemically and mechanically mainly in limestone or mollusc shells .
features
The unobstructed, non-inflated housing is 25 millimeters long. It is oblong-ovate (modioliform) in outline. The housings gape at the ventral edge. It is uneven, the vertebrae are almost at the front end. The very long posterior dorsal margin is almost straight to slightly convex and merges into the well rounded posterior end. The very short anterior dorsal margin is straight and merges into the tightly rounded anterior end diagonally below the vertebrae. The front part of the ventral margin is almost straight, the rear part widely rounded.
Lunula and area are not available. The externally located ligament is a dark brown band that extends behind the vertebrae for about half the length of the posterior dorsal margin. The lock is toothless. The mantle is deeply indented, the bay almost extends to the (front) vortex.
The gray-white, aragonitic shell is thin and fragile. It consists of two layers, an outer layer with crossed lamellas and an inner layer. The surface is provided with fairly regular fine ribs and depressions parallel to the edge. The edge of the case is smooth. The periostracum is light brown to dark brown.
The siphons are short and grown together almost to the ends. The entrance of the inflow siphon is surrounded by a ring of 18 papillae, with shorter and longer papillae alternating. The outlet of the outflow siphon is surrounded by 24 papillae; in the middle there is a fold-out cone-like structure. The finger-shaped foot sucks on the wall of the borehole and is also attached to the wall with a few byssus threads.
The animals create a bottle-shaped borehole in the hard substrate (organic or inorganic), which they line for the most part with lime. Only a smaller area in the rear dorsal area (after the animal has orientated itself in the borehole) remains free of a calcium lining. In addition, a kind of collar is placed around the opening of the borehole, that is, the borehole is extended by a short tube.
Geographical distribution, habitat and way of life
The range of the species extends from the British Isles to Morocco , in the Mediterranean and the Black Sea . She also lives in the waters of the Atlantic islands of St. Helena , the Canary Islands , the Cape Verde Islands ,
It occurs from around two meters to a depth of 180 meters. Rocellaria dubia lives in five different habitats or fauna communities in the southeastern Adriatic Sea :
- in accumulations of rocks under water in the coastal area (concrete walls are also drilled under the water line!)
- in association with photophilic and coral algae
- in association with other types of mussels, e.g. B. the Noah's Ark mussel ( Arca noae ) Linnaeus, 1758, the bearded mussel ( Modiolus barbatus (Linnaeus, 1758)), Pseudochama gryphina (Lamarck, 1819) and the scallop shell ( Mimachlamys varia (Linnaeus, 1758))
- mixed in sand with broken shells in meadows by Cymodocea nodosa (Ucria) Ascherson, 1869
- on muddy sand covered in shell fragments.
Here she is drilling in calcareous hard parts or rock. In the eastern Adriatic it is one of the most common types of mussels, with up to 10 individuals in 10 square centimeters. This is where the shells of the European oyster ( Ostrea edulis ), the noble pen shell ( Pinna nobilis ), the rough clam ( Venus verrucosa ) and Glycymeris violascens are drilled. If the shells are pierced down to the soft body of the infected specimen, they form a callus from the inside.
Taxonomy
The taxon was established in 1777 by Thomas Pennant under the original name Mya dubia . It is more or less the type species of the genus Rocellaria de Blainville, 1828, since the formal type Gastrochaena modiolina Lamarck, 1818 is a younger synonym of Rocellaria dubia .
supporting documents
literature
- Brian Morton, Melita Peharda, Mirela Petrić: Functional morphology of Rocellaria dubia (Bivalvia: Gastrochaenidae) with new interpretations of crypt formation and adventitious tube construction, and a discussion of evolution within the family. Biological Journal of the Linnean Society, 104: 786–804, 2011. PDF (ResearchGate)
- 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. 151)
- Guido Poppe. Yoshihiro Goto: European Seashells Volume 2 (Scaphopoda, Bivalvia, Cephalopoda) . 221 pp., Verlag Christa Hemmen, Wiesbaden 1993 (2000 unc. Reprint), ISBN 3925919104 (p. 129)
On-line
Individual evidence
- ↑ George Brettingham Sowerby II : Illustrated index of British shells. containing figures of all the recent species, with names and other information. XV S., XXIV plate London, Simpkin, Marshall & Co., 1859 Online at www.biodiversitylibrary.org (plate 1)
- ^ Thomas Pennant: British Zoology. Vol. IV. Crustacea. Mollusca. Testacea. P. III-VIII, 1-154, Taf. I-XCII (= 1-93), London, White, 1777 Online at www.biodiversitylibrary.org (p. 82)
- ↑ MolluscaBase: Rocellaria dubia (Pennant, 1777)
