Thymallus brevirostris
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| Kessler , 1879 |
Thymallus brevirostris ,also called Mongolian Grayling in English ,蒙古 茴 魚 in Chinese , Pinyin méng gŭ huí yú , Russian хариус монгольский or монгольский хариус , is a predatory grayling species from Central Asia .
distribution
The fish species is native to parts of the Russian Federation and the lake region of Mongolia . They are found in Daingol-Nur Lake, in the river basin of Khovd -Flusses, in the rivers and lakes of the Altai Mountains (z. B. Kyrgyz Nor-Lake), where they often together with the Arctic grayling occurs. The range of Thymallus brevirostris is limited to the Central Asian Basin of western Mongolia and the border region to Kazakhstan , as well as the Tuva Republic in southern Siberia .
to form
The Mongolian grayling is considered by researchers to be a type of relic from the Tertiary . Morphological and ecophysiological studies of the species from the Mongolian Hoton-Nuur Sea came to the conclusion that the species may have two morpho-ecological forms . Data on growth, eating habits, gender, and age composition manifested this observation. Today it is believed that it is a predatory and a ground-feeding type.
description
The Mongolian grayling is usually 39 centimeters long. The largest fish weighed 3.12 kilograms, was 65 centimeters long, and was caught in Khurgan Lake in Mongolia in 2010. The benthic nourishing and the predatory forms do not differ in body shape and color. The dorsal side is blackish, the ventral side light. Black spots are evenly present on the sides, absent in some specimens. The snout is rounded, the mouth terminal . In adult animals of the predatory form, the upper jaw extends at least below the rear edge of the eye.
The dorsal fin is small, a reddish-purple adipose fin is present. The fish has the following fin formula : dorsal 4–8 (18–20 soft rays), anal 3–4 (8–12 soft rays).
Way of life
Thymallus brevirostris is mainly found in isolated mountain waters. The Mongolian grayling claims the same habitat as the Arctic grayling, with which it z. T. forms hybrids. The grayling is omnivorous and predatory at certain times of the year. During the summer months it inhabits mountain rivers and lakes in all deep zones. In autumn and winter, it forms large swarms in front of the river mouths in lakes before spawning. The reproduction of the Mongolian grayling is only possible in cold, oxygen-rich water below temperatures of +20 ° C.
Economical meaning
In addition to target fishing such as Taimen and Altai-Osman , organizers of adventure fishing trips also offer targeted fishing for Mongolian grayling in remote mountain regions.
Hazardous situation
The living conditions of the Mongolian grayling in Lake Khar Us were examined. Intensified agriculture, climate change with the associated changes in water temperature and the construction of the Durgun hydroelectric dam are endangering the population of Thymallus brevirostris . The high water pressure and the associated currents cannot be overcome by the Mongolian grayling during their spawning migrations. Distribution and migration of the fish species in the lake region of Khar Us, Durgun, Khar, Airag and Khyargas separate the populations into a western and an eastern part. Their spawning grounds have shifted due to human construction.
literature
- Lev Semyonovich Berg: Fresh-water fishes of Soviet Union and adjacent countries . 1948, p. 423
- AL Antonov: A new species of grayling * Thymallus burejensis * sp. nova (Thymallidae) from the Amur basin , 2004, p. 445
- Maurice Kottelat: Fishes of Mongolia. A check-list of the fishes known to occur in Mongolia with comments on systematics and nomenclature , The World Bank, Washington, DC, 2006, p. 24
Web links
Individual evidence
- ↑ a b c d e Thymallus brevirostris on Fishbase.org (English)
- ↑ http://www.fishwise.co.za/Default.aspx?TabID=110&SpecieConfigId=204169&GenusSpecies=Thymallus_brevirostris ( 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.
- ↑ E. Froufe, I. Knizhin and S. Weiss: Phylogenetic analysis of the genus Thymallus (grayling) based on mtDNA control region and ATPase 6 genes, with inferences on control region constraints and broad-scale Eurasian phylogeography. In: Molecular Phylogenetics and Evolution 34, 2005, pp. 106-117 ( online )
- ↑ a b c d e Yu. V. Slynko, B. Mendsaykhan, AN Kas'anov: On Intraspecies Forms of the Mongolian grayling (Thymallus brevirostris Kessl.) From Hoton Nur Lake (Western Mongolia). In: Journal of Ichthyology , 2010 ( online )
- ↑ http://www.fishing-worldrecords.com/scientificname/Thymallus%20brevirostris/show
- ↑ a b c Johannes Schöffmann: The grayling (Thymallinae) of Mongolia from the three different drainage areas. ( Online )
- ↑ "found in landlocked basins"
- ↑ http://fishingtours.corcon.eu/en/Probably-the-biggest-Grayling-in-the-World.aspx
- ^ A Threat to the Mongolian grayling
