Blaalig

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Blaalig
Systematics
Cohort : Euteleosteomorpha
Order : Salmonid fish (Salmoniformes)
Family : Salmon fish (Salmonidae)
Subfamily : Coregoninae
Genre : Coregonus
Type : Blaalig
Scientific name
Coregonus zuerichensis
( Nüsslin , 1882)

The Blaalig ( Coregonus zuerichensis ) is a freshwater fish from the genus Coregonus that is endemic in two Swiss lakes . As a food fish, it plays a regional role.

features

Like the other species of the Coregonus genus , the Blaalig has a herring-like shape with numerous silvery, shiny round scales and an adipose fin . The Blaalig seldom exceeds 42 centimeters in length.

distribution

The Blaalig was originally endemic in four lakes in Switzerland, namely in Lake Zurich , Lake Walen , Lake Pfäffik and Lake Greifensee , although the species has been extinct in the latter two waters for some time. In the other two, however, it is still present in larger numbers.

Way of life

The species feeds on plankton and lives pelagic . The spawning takes place in November or December in a sea depth between 12 and 100 meters.

Endangerment and Use

Although the Blaalig is extinct in the Pfäffikersee and Greifensee, it is not endangered in the other two bodies of water because the populations are large enough and invasive species that could pose a potential threat are kept under control. Therefore it is listed on the IUCN Red List under "Least Concern". The species is valued as a tasty food fish.

Systematics and taxonomy

The diversity of the Coregon species, which have been described from the Swiss lakes, represents a great challenge for the taxonomists. These species probably only developed after the end of the Würm glacial period around 10,000 years ago, when the glaciers retreated and the Alpine lakes receded formed according to glacial morphological criteria. Their morphological and genetic distinguishing features are therefore not very pronounced. While up to five distinguishable Coregonus species are given in the literature for Lake Walen and Lake Zurich , in practice only two or three species can be identified for these lakes. In addition to the Blaaling ( Coregonus zuerichensis ), these are the Hägling ( Coregonus heglingus ) and the Grundler ( Coregonus duplex ).

Individual evidence

  1. ↑ Blaalig on Fishbase.org (English)
  2. ↑ Maurice Kottelat & Jörg Freyhof: Handbook of European Freshwater Fishes . 2007 ISBN 978-2-8399-0298-4
  3. ↑ Coregonus zuerichensis in the IUCN Red List of Threatened Species 2015.1. Posted by: Freyhof, J. & Kottelat, M., 2008. Accessed June 2, 2015.
  4. ^ Paul Steinmann: Monograph of the Swiss Koregons. Contribution to the problem of the emergence of new species. Special part. Swiss Journal for Hydrobiology 12, pp. 340–491, 1950
  5. ↑ Pascal Vonlanthen, Bänz Lundsgaard-Hansen, Hudson Alan and Ole Seehausen: Investigations into the relationship of the whitefish from Lake Zurich, Lake Walen and the Linth Canal. Eawag on behalf of the Office for Nature, Hunting and Fishing, St. Gallen 2008

literature

  • Paul Steinmann: Monograph of the Swiss Koregons. Contribution to the problem of the emergence of new species. Special part. Swiss Journal for Hydrobiology 12, pp. 340–491, 1950
  • Maurice Kottelat & Jörg Freyhof: Handbook of European Freshwater Fishes . 2007 ISBN 978-2-8399-0298-4

Web links