Lagoon cockle
| Lagoon cockle | ||||||||||||
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Lagoon cockle ( Cerastoderma glaucum ) |
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| Scientific name | ||||||||||||
| Cerastoderma glaucum | ||||||||||||
| ( Jean Louis Marie Poiret , 1789) |
The lagoon cockle ( Cerastoderma glaucum ) is a mussel - species from the family of cockles (Cardiidae) (order Cardiida ). It is also found in the North and Baltic Seas.
features
The equally flared, moderately inflated case is rounded and sub-square and is up to 4.5 cm (Willmann: 5 cm) long. It is slightly longer than it is high and only slightly unequal, the very strongly pronounced vertebrae are slightly in front of the middle of the length of the case. The rear edge is somewhat elongated. The ventral side tapers off sharply in cross-section. The edge of the case is slightly notched. The outer ribs are also visible on the inside. The ligament is on the outside, the area is sunk. The lock of the right valve has two main teeth and paired front and rear posterior teeth. The left flap has two main teeth and a single anterior and posterior posterior tooth. The surface line is complete and not indented. The two sphincters are rounded and about the same size.
The skin is thin and brittle. It is yellowish to greenish-brown on the outside, occasionally with intense brown spots at the rear end. The ornamentation consists of 22 to 28 radial ribs. In most populations, the number of ribs averages between 22 and 24 ribs. The ribs are rounded in profile in the front and middle part of the housing, rather angled in the rear part, and at the rear end they lose themselves more and more. The spaces between the ribs are about as wide as the ribs. The ribs on the front and middle part of the housing show strip-like transverse bulges that weaken with age or can also disappear at the rear end. The periostracum is green-brown.
Geographical distribution and habitat
The distribution area extends in the eastern Atlantic from Norway to the Iberian Peninsula and the Mediterranean . It is also found in the North Sea and in large parts of the Baltic Sea . It lives in more brackish habitats on sandy and muddy soils.
Way of life
The lagoon cockle is separate sexes. The sex products are given off is free water, where fertilization also takes place. The larvae hatch after about 72 hours with a D-shaped larval housing with a length of 110 µm. In laboratory tests, the highest hatching and survival rates were observed at salt contents between 25 and 30 ‰. It can still bear a salt content of only 4 ‰. The species is also more frost-resistant than the common cockle ( Cerastoderma edule ).
Taxonomy
The taxon was established in 1789 by Jean Louis Marie Poiret in the original combination Cardium glaucum . There are over 30 synonyms , mainly names of varieties. The taxon often appears in the literature with the (wrong) author Jean-Guillaume Bruguière .
supporting documents
literature
- Rudolf Kilias: Lexicon marine mussels and snails. 2nd edition, 340 p., Verlag Eugen Ulmer, Stuttgart 1997 ISBN 3-8001-7332-8 (p. 62)
- 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. 101/02)
- Guido Poppe. Yoshihiro Goto: European Seashells Volume 2 (Scaphopoda, Bivalvia, Cephalopoda) . 221 pp., Verlag Christa Hemmen, Wiesbaden 1993 (2000 unc. Reprint), ISBN 3925919104 (p. 95)
- Rainer Willmann: Mussels of the North and Baltic Seas. Neumann-Neudamm, Melsungen 1989, ISBN 3-7888-0555-2 (pp. 126–30 as Cerastoderma lamarcki )
On-line
- Marine Bivalve Shells of the British Isles: Cerastoderma glaucum (Bruguière, 1789) (website of the National Museum Wales, Department of Natural Sciences, Cardiff) (accessed 19 May 2017).
- Marine Species Identification Portal: Cerastoderma glaucum (Bruguière, 1789) (accessed May 19, 2017).
- Cerastoderma glaucum (Bruguière, 1789) Conchological Society of Great Britain and Ireland (accessed May 19, 2017).
Individual evidence
- ↑ Jean Louis Marie Poiret: Voyage en Barbarie, ou lettres écrites de l'ancienne Numidie pendant les années 1785 & 1786, sur la religion, les coutumes & les mœurs des maures & des arabes-bédouins; with one essai sur l'histoire naturelle de ce pays. Seconde partie. Pp. 1–315, La Rochelle, Paris, 1789 Online at www.biodiversitylibrary.org (pp. 13–15)
- ↑ MolluscaBase: Cerastoderma glaucum (Bruguière, 1789)
