Coregonus

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Coregonus
Coregonus maraena

Coregonus maraena

Systematics
Overcohort : Clupeocephala
Cohort : Euteleosteomorpha
Order : Salmonid fish (Salmoniformes)
Family : Salmon fish (Salmonidae)
Subfamily : Coregoninae
Genre : Coregonus
Scientific name
Coregonus
Linnaeus , 1758

Coregonus is a genus of fish species from the order of the salmon-like (Salmoniformes). German common names include whitefish , Rhein refueling (also in the spelling whitefish ), whitefish , whitefish (or spelling whitefish), coregonids and whitefish (also in the spelling Schnepel). A German name can stand for different species; many species have several common names depending on the region.

General

Species allocation

The genus Coregonus is the most species-rich within the order of the salmon-like species. It is difficult to distinguish the individual species from their external appearance; The gill spines , which vary in number, shape and arrangement from species to species, serve to identify the species.

Happen

The Coregons mostly live in deeper lakes (from approx. 50 m), for example Lake Constance , Chiemsee and other pre-Alpine lakes , such as Walchensee , in the chain of lakes around Lake Biel , Lake Neuchâtel and Lake Geneva , the Salzkammergut Lakes , the Salzburg Lakes , the Carinthian lakes , the northern Italian lakes and several other peripheral and inner Alpine lakes, as well as in northern German lakes such as the Arendsee , Breiten Luzin , Müritz , Plöner See , Ratzeburger See , Schaalsee , Schweriner See , Selenter See , Stechlinsee , Werbellinsee and others. In some places, flooded opencast mine holes were filled with Coregonus species. Some species came or are also found in salt water , for example in the Baltic Sea and North Sea .

nutrition

The Coregons feed - depending on the species - on plankton or larger animals. Closely related species have often occupied different ecological niches . They differ, for example, in whether they take their food primarily as hovering in the open water or as so-called whitefish on the ground. To collect the plankton, some species still have distinct mucus-producing epibranchial organs in the pharynx .

Origin of name

The system is confusing due to many renaming. The German species names are even more confusing as they change from region to region (see above). The only national names are the educational language "Coregonen" for the whole genus and "Schnäpel" or "Schnepel". 'Coregonus' (Greek) means “angle pupil” - because the eye hole is not circular, but rather has a section in the direction from which mainly food is visible (this does not only apply to whitefish, but to most fish).

evolution

In particular, the populations in the glacial lakes formed after the Ice Age can be seen as an example of the geographical isolation that can lead to speciation (see evolutionary theory ). This also results in the multitude of local forms, which only partially represent different real species , but mostly races / subspecies that differ more in appearance than in genes.

Systematics

The genus Coregonus forms the subfamily Coregoninae within the salmon fish together with Stenodus and Prosopium .

fishing

Incense whitewash in Nikolaiken , East Prussia (1920s)

The coregons are tasty food fish that are fried , smoked , (rarely) boiled and steamed.

Specifically, since the coveted as a food fish swing Brenken ( whitefish , Edelmaräne) from plankton feed, you can not use a conventional them fishing catch, so they traditionally with the gill net or large pots is adjusted. This catch is also limited to the mating season in June and July, as the fish stay in deeper places in the other months. The angler can catch vendace with the help of hedgerows . These are multiple hook systems ("paternoster") with fishhooks disguised as mosquito larvae , so-called nymphs .

Danger

Many coregons and whitefish are endangered fish species. In both North America and Europe, stocks were severely overfished in the 19th and 20th centuries . In addition, stocks collapsed due to competition from alien fish species. Today, water pollution in particular is considered to be the greatest threat. Another reason for the rarity of these fish are the severely restricted distribution areas , some of which only include a certain lake area. Twelve  taxa are considered to be extinct or presumed to be extinct: Coregonus alpenae , Coregonus johannae , Coregonus reighardi (officially listed as critically endangered, but no longer proven since the 1980s), Coregonus gutturosus , Coregonus bezola , Coregonus restrictus , Coregonegonus fera , Coregonus fera , Coregonus hiemalis , Coregonus hoferi (officially listed as critically endangered, but no longer detected since the 1940s), Coregonus oxyrhynchus and Coregonus kiyi orientalis . Another 19 taxa, including Coregonus arenicolus , Coregonus bavaricus , Coregonus kiyi , Coregonus candidus and Coregonus confusus , are considered endangered, critically endangered or critically endangered.

Species overview

literature

  • Maurice Kottelat: European Freshwater fishes. An heuristic checklist of the freshwater fishes of Europe (exclusive of former USSR), with an introduction for non-systematists and comments on nomenclature and conservation . Biologia (Bratislava) Sect. Zool., 52 (Suppl.). 1997.
  • Maurice Kottelat & Jörg Freyhof: Handbook of European Freshwater Fishes . 2007, ISBN 978-2-8399-0298-4 .
  • Lev Semenovich Berg : Freshwater fishes of the USSR and adjacent countries . Volume 1, 4th Edition, 1962. Israel Program for Scientific Translations Ltd, Jerusalem. (English translation of the 1948 Russian edition).
  • David Stephen Lee et al .: Atlas of North American Freshwater Fishes . North Carolina State Museum of Natural History, Raleigh 1980, ISBN 0917134036 .
  • Lawrence M. Page , Brooks M. Burr : Peterson Field Guide Series - A Field Guide to Freshwater Fishes: North America North of Mexico . Houghton Mifflin Company, Boston, New York 1991, ISBN 0-395-91091-9 .
  • Fish in Brandenburg. Current mapping and description of the fish fauna of the Brandenburg region. Institute for Inland Fisheries V. Potsdam-Sacrow, 2011.

Web links

Commons : Coregonus  - collection of images, videos and audio files

Individual evidence

  1. ↑ Swiss Fisheries Advisory Service FIBER: Whitefish - Species Diversity in Switzerland
  2. ↑ Renke . In: Meyers Konversations-Lexikon . 4th edition. Volume 13, Verlag des Bibliographisches Institut, Leipzig / Vienna 1885–1892, p. 728.
  3. ↑ Belche / Balche . In: Jacob Grimm , Wilhelm Grimm : German dictionary . Hirzel, Leipzig 1854–1961 ( woerterbuchnetz.de , University of Trier).
  4. ↑ whitefish . In: Merck's Warenlexikon . 3rd ed. 1884 ff., P. 341 f.