Huchen ( Hucho hucho ), underwater shot from the Drina between Bosnia and Serbia.
|( Linnaeus , 1758)|
The Danube salmon ( Hucho hucho ), and Danube salmon or red fish , but also called Donausalm 'colonized the grayling - and barbel region of rivers, especially the upper and middle Danube and many of the right-hand tributaries .. (U a of Drava , Drina , Melk , Mur , Pielach and the lower Gail ). The huchen is also a food fish , but it is rare and critically endangered. It was named Fish of the Year 2012 in Austria and Fish of the Year 2015 in Germany .
On average, this fish is between 60 and 120 cm long, with a maximum length of 150 cm. The body is elongated, spindle-shaped and almost round in cross-section. The head is flattened and reaches a length of 22 to 24% of the standard length . The big mouth extends far behind the eyes.
Huchen are brownish to greenish-gray in color on the back, the sides are reddish or shimmering copper-colored and are covered with irregularly arranged small, dark dots. The belly is whitish. The red spots typical of many salmon fish in Europe are missing.
The scales of the huchen are very small, 180 to 200 are counted along the lateral line , 23 to 27 between the lateral line and the relatively large adipose fin (including lateral line scales). The number of vertebrae is 66 to 72, that of the gill rake on the first gill arch is 13 to 19. The ploughshare has 4 to 8 strong, hook-shaped teeth on its rear edge. The caudal fin is notched. The fin formula is dorsal iii – v / 8–14, anal iii – v / 7–14.
Way of life
In contrast to many other salmon fish, the huchen lives constantly in fresh water, mostly in deeper sections of fast-flowing, oxygen-rich rivers. He is a loyal, territorial loner. Young huchen feed on all kinds of invertebrates, adults are predatory fish and primarily hunt fish, but also other small vertebrates such as amphibians, mice swimming in the water or ducklings. During the spawning season in March or April, huchen migrate a little upstream. Spawning takes place in shallow pits that the female hits with her tail beforehand. A female lays around 1000 eggs per kilogram of body weight, which have a diameter of 5 mm. At a water temperature of 8 to 10 ° C, the larvae hatch after about 35 days. The fast-growing young fish reach sexual maturity after three to four years.
The huchen was already in 1758 by Carl Linnaeus , the founder of the classification system by the binomial nomenclature , as Salmo hucho described and 1866 by the German zoologist Albert Günther of the subgenus Hucho assigned, which was later raised to generic rank. In addition to the huchen, three other species belong to the genus Hucho : Hucho bleekeri , Hucho ishikawae and the Taimen ( Hucho taimen ). These three types are found in China, Korea, and Russia.
Within the salmon fish, the genus Hucho belongs to the subfamily Salmoninae and within this subfamily, together with its purely East Asian sister genus Brachymystax, it forms a systematic unit ( clade ) which is opposite to the other Salmoninae genera ( Oncorhynchus , Parahucho , Salmo , Salvelinus , Salvethymus ).
Breeding is of great importance for the huchen , as there are only a few bodies of water where natural reproduction is sufficient for species conservation. To do this, the parent animals are caught shortly before spawning, or they are kept in special tanks. When the brood has reached a size of 4–10 cm, it is released in suitable places.
Hazard and protection
The World Conservation Union IUCN is the Danube salmon in the Red List of Threatened Species and rated him as endangered ( Endangered ). The reasons for this are bank barriers and straightening , increasing water pollution , waterlogs that destroy spawning grounds and juvenile fish habitats, and weir systems without fish ladders , which block the huchen from getting to their spawning grounds. The destruction of the spawning grounds through gravel mining in the river beds is also badly affecting the stocks.
Natural populations of the Huchen are listed by the European Union in Appendix II of the Habitats Directive ; it is thus a type of common interest, for whose preservation the member states must designate special protected areas.
Contrary to the trend mentioned, the Isar was renatured in Munich from 2000 to 2011 . In 2018, spawning grounds for eight huchen breeding pairs in the urban area were identified and protected. However, the loss of juvenile fish by predators must be compensated for by annual stocking with specimens of the appropriate size.
Concern about the extinction of the autochthonous species played a role in the dispute about the construction of the Mur power plant in Graz-Puntigam . A model of the fish more than 1 m long was carried along during demonstrations. The zoologist Steven Weiss from the University of Graz examined the population in Graz in 2010 on behalf of the Styrian environmental attorney and estimates that the population will "almost certainly die out" with the construction of the power plant. In 2007, Mayor Siegfried Nagl declared to fishermen “The habitat of this beautiful fish must be preserved in Graz!” And a few years later decided to build the power plant. The worker fishermen and the nature conservation association supported the “Save the Mur” platform, opposed the construction of a power plant and called for a public survey in Graz. Such a referendum was not carried out, the power plant was built from around 2017 and is scheduled to go into operation in 2019.
In 2012 the Huchen was “Fish of the Year” in Austria.
- Fritz Terofal: Steinbach's natural guide, freshwater fish. Ulmer, Stuttgart 2003, ISBN 3-80014-296-1
- Hucho on Fishbase.org (English)
- Alexis Crête-Lafrenière, Laura K. Weir, Louis Bernatchez: Framing the Salmonidae Family Phylogenetic Portrait: A More Complete Picture from Increased Taxon Sampling. PLOS ONE , 2012, 7 (10): e46662. DOI: 10.1371 / journal.pone.0046662
- SV Shedko, IL Miroshnichenko, GA Nemkova: Phylogeny of salmonids (Salmoniformes: Salmonidae) and its molecular dating: Analysis of mtDNA data. Russian Journal of Genetics, June 2013, Volume 49, Issue 6, Pages 623-637. DOI: 10.1134 / S1022795413060112
- Hucho hucho in the IUCN Red List of Threatened Species 2014.3. Posted by: Freyhof, J. & Kottelat, M., 2008. Retrieved November 29, 2014 ..
- Thomas Anlauf: The predatory fish who loves the Munich Isar. In: SZ.de . August 8, 2018, accessed October 22, 2018 .
- Huchen in the Mur an autochthonous species , derstandard.at, October 28, 2010, accessed December 23, 2018.
- Huchen wedding in threatened Mur , derangelhaken.at, April 2016 at the latest, accessed December 23, 2018. With pictures by ("Huchen-Franz") Franz Keppel.
- Graz: The Wedding in the Mur , kleinezeitung.at, April 10, 2016, accessed December 23, 2018.