Sandstone

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Sandstone
Systematics
Cohort : Euteleosteomorpha
Order : Salmonid fish (Salmoniformes)
Family : Salmon fish (Salmonidae)
Subfamily : Coregoninae
Genre : Coregonus
Type : Sandstone
Scientific name
Coregonus arenicolus
( Kottelat , 1997)

The Sandfelchen ( Coregonus arenicolus ) is an endemic freshwater fish from the family of salmon fish (Salmonidae) living in Lake Constance .

features

Like the other vendace, the sand fluff has a herring-like shape with a multitude of silvery, small round scales , but also has an adipose fin . It has 13 dorsal and 12 anal soft rays. The maximum dimension is 550 mm. The species can be distinguished from the other species of the genus Coregonus that live in Lake Constance on the basis of the number of gill spines . When sand whitefish there are 18 to 27 rather short, the whitefish ( Coregonus waiting manni ) and course fish ( Coregonus macrophthalmus ) more than the 28th

distribution

The sand fluff is endemic in Lake Constance . It is far rarer than the other Lake Constance fluffy blue and gangfish and, in contrast to these, is of no importance for fishing.

Way of life

The sand fluff lives benthopelagic near the ground or the coast. It prefers to take on invertebrates living on the ground, mainly mussels or snails. The young hatch near the shore from November to December.

Taxonomy and systematics

The division of the genus Coregonus into species is one of the most difficult problems of the European taxonomy of fish and has not yet been satisfactorily clarified. The sand fluff was considered to be a form or population of the species Coregonus nasus until 1997 , which today is considered to be purely arctic. It is closely related to the other Coregonus species from Lake Constance and forms a clade with these and the species from the Danube region . The species are so genetically similar that they can not be reliably differentiated from one another using DNA barcoding . Some taxonomists therefore do not consider them to be in their own right, but only as ecotypes of several broad species. It is assumed that speciation has only occurred since the last Ice Age ( Würm Ice Age ) and that the species is therefore only a few thousand years old.

It is possible that artificial hybrids were formed with the gang fish, which also lives there, as part of a program that ran until 2004. Even today, around 350 million juvenile fish of the species gangfish and blue flies are bred in six farms on Lake Constance and released to support the stocks in the lake .; however, no sandstone is used anymore.

In more recent studies, in which fish occurring today were compared with museum material of the same species, the morphological differences between the Coregonus species now living in Lake Constance were smaller than those of earlier forms of the same species. A possible reason for this is that the previously clearly separated ecological niches of the species have lost their separation due to eutrophication, and the species have converged in their way of life. This presumably also led to natural hybridizations, but these have not been genetically proven with certainty for the sand fluff. In contrast to the whitefish species that tend to live in open water (pelagic), the species was unable to increase its populations again in the lake, which has become cleaner again. The other Coregonus species that used to live benthically in Lake Constance , the Bodensee Kilch Coregonus gutturosus , which, in contrast to the sand fluff, spawned in deeper water, is now extinct.

Hazard and protection

The sand fluff is listed on the IUCN Red List as "Vulnerable (VU)" (endangered). In Germany it is considered to be endangered by rarity (category R), but after earlier declines due to the eutrophication of Lake Constance , the population is now considered stable. In Austria it is considered endangered. The species is listed in Appendix V of the Habitats Directive of the European Union. Appendix V lists endangered species that are also used economically; special regulations are stipulated for their extraction from nature. The conservation status of the species is assessed by the Federal Agency for Nature Conservation in Germany to be favorable (status: 2013).

Individual evidence

  1. ↑ Harald Ahnelt (2008): Identification key for the fish occurring in Austria. download
  2. ↑ a b c Jörg Freyhof (2009): Red list of the lampreys and fish reproducing in freshwater (Cyclostomata & Pisces). Conservation and Biodiversity 70 (1): 291–316.
  3. ^ Alan G. Hudson, Pascal Vonlanthen, Ole Seehausen (2010): Rapid parallel adaptive radiations from a single hybridogenic ancestral population. Proceedings of the Royal Society Series B doi : 10.1098 / rspb.2010.0925 (open access)
  4. ↑ Knebelsberger, T., Dunz, AR, Neumann, D., Geiger, MF (2015): Molecular diversity of Germany's freshwater fishes and lampreys assessed by DNA barcoding. Molecular Ecology Resources 15: 562-572. doi : 10.1111 / 1755-0998.12322
  5. ↑ Coregonus arenicolus at fishbase.org
  6. ↑ Eckmann, Reiner; Kugler, Michael; Ruhlé, Christian (2007): Evaluating the success of large-scale whitefish stocking at Lake Constance. Advances in Limnology 60: 361-368.
  7. ↑ P. Vonlanthen, D. Bittner, AG Hudson, KA Young, R.Müller, B. Lundsgaard-Hansen, D. Roy, S. Di Piazza, CR Largiader O. Seehausen Eutrophication causes speciation reversal in whitefish adaptive radiations. Nature 482: 357-362. doi : 10.1038 / nature10824
  8. ^ Philipp Emanuel Hirsch, Reiner Eckmann, Claus Oppelt, Jasminca Behrmann-Godel (2013): Phenotypic and genetic divergence within a single whitefish form - detecting the potential for future divergence. Evolutionary Applications 6 (8): 1119–1132. doi : 10.1111 / eva.12087
  9. ↑ Georg Wolfram, Ernst Mikschi: Red List of Fish (Pisces) Austria. In KPZulka (editor): Red lists of endangered animals in Austria. Checklists, hazard analyzes, need for action. - Green series (Ed. Ministry of Life) Volume 14/2 (reptiles, amphibians, fish, moths, mollusks), Böhlau Verlag, Vienna: 61-198.
  10. ↑ Federal Agency for Nature Conservation (publisher): List of the species occurring in Germany in Annexes II, IV, V of the Habitats Directive (92/43 / EEC). PDF at www.bfn.de  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.@1@ 2Template: Toter Link / www.bfn.de  
  11. ↑ BfN: National Habitat Report 2013, Species in the continental biogeographical region PDF at www.bfn.de

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