Icelandic scallop

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Icelandic scallop
Chlamys islandica.jpg

Icelandic scallop ( Chlamys islandica )

Systematics
Subclass : Autolamellibranchiata
Subclass : Pteriomorphia
Order : Pectinida
Family : Scallops (Pectinidae)
Genre : Chlamys
Type : Icelandic scallop
Scientific name
Chlamys islandica
( OV Müller , 1776)
Copy from the Natural History Museum in Leiden

The Icelandic scallop ( Chlamys islandica ) or northern scallop is a type of mussel from the family of the scallops (Pectinidae) and the type of the genus Chlamys . The scientific name used to be Pecten islandicus .

features

The case has 50 to 132 fine ribs and is 60 to 116 mm long. The ribs are crossed by concentric lines of growth; fine scales can sit on the crossing points. Housing shapes and colors are very variable, covering all shades from white to yellow and red to black. The surfaces of the housing are often populated by barnacles of the genus Balanus .

Way of life, occurrence and distribution

Chlamys islandica lives at depths of 8 to 1,300 m on rock and gravel ground, to which it attaches itself firmly with byssus threads . It needs water temperatures below 10 ° C and can withstand temperatures slightly below 0 ° C. This species occurs recently in the northern Atlantic , in the western Atlantic south to Cape Cod , in Europe with records in Iceland , on the Shetland Islands and the Norwegian islands of Spitzbergen , Lofoten and Vesterålen and Jan Mayen . It also occurs sporadically in the North Sea to Heligoland and also on the Azores .

The reproduction takes place through the release of eggs and sperm into the open water, where then fertilization takes place. Planktonic -living Veliger larvae develop from the fertilized eggs . She can live up to 23 years old.

Subfossil finds

When trawling in the western Mediterranean , subfossil mussel shells from the last ice age (more than 11,000 years ago) are regularly found. Light-colored specimens from the period of climate change towards the end of this Ice Age can be seen e.g. B. found at the mouth of the Clyde in Scotland. In the Mediterranean there are even older specimens that have been blackened by the fossilization conditions .

Commercial importance

The species has been commercially fished intensively in Norway since 1985, and in Iceland since 1969. In 1986, the maximum was landed in Iceland with 12,700 tons. The annual catch level later stabilized at around 8,000 to 9,000 t. Since 2000, however, the stocks have declined sharply. In 2003 the landed amount was only 800 t. However, the decline is not due to overfishing, as the largest decline occurred in an area where the stocks were not fished at all. The causes can be found in the constantly rising sea temperatures.

Individual evidence

  1. ↑ C. islandica at fischdb.de . The German name Northern Scallop is actually more appropriate, since the mussel is not only found in Icelandic waters, but in the entire northern Atlantic, but the variant Icelandic Scallop is used more often because of the reference to the scientific name.
  2. ↑ Evidence in Northern Norway (Norwegian; PDF; 21 kB)
  3. ^ Shell finds at the mouth of the Clyde ( Memento from August 30, 2005 in the Internet Archive )
  4. ↑ Jonasson et al., P. 298

literature

  • Guido Poppe and Yoshihiro Goto: European Seashells Volume 2 (Scaphopoda, Bivalvia, Cephalopoda) . 221 pp., Verlag Christa Hemmen, Wiesbaden 1993 (2000 unc. Reprint), ISBN 3-925919-10-4
  • Svein Erik Fevolden: Genetic differentiation of the Iceland scallop Chlamys islandica (Pectinidae) in the northern Atlantic Ocean. In: Marine Ecology Progress Series, 51: 77-85, Oldendorf / Luhe 1989, ISSN  0171-8630
  • Jónas P. Jonasson, Gudrun Thorarinsdottir, Hrafnkell Eiriksson, Jon Solmundsson and Gudrun Marteinsdottir: Collapse of the fishery for Iceland scallop ( Chlamys islandica ) in Breidafjordur, West Iceland. ICES Journal of Marine Science, 64: 298-308, London 2007, ISSN  1054-3139

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