Lenok

{{Short description|Genus of fishes}} {{Automatic taxobox | image = Brachymystax lenok.jpg | image_alt = | image_caption = ''Brachymystax lenok'' | fossil_range = {{fossil_range|Miocene|Recent}} | taxon = Brachymystax | authority = Günther, 1866<ref>{{ITIS |id=623307 |taxon=''Brachymystax''}}</ref> | type_species = ''Salmo lenok''<ref name=fishbase/> | type_species_authority = Pallas, 1773 | subdivision_ranks = Species | subdivision_ref = <ref name=fishbase/> | subdivision = * ''Brachymystax lenok'' (Pallas, 1773) * ''Brachymystax savinovi'' Mitrofanov, 1959 * ''Brachymystax tumensis'' T. Mori, 1930 * ''Brachymystax tsinlingensis'' S. C. Li, 1966 | synonyms = | synonyms_ref = {{Citation needed|date=November 2023}} }}

'''Lenoks''', otherwise known as '''Asiatic trout''' or '''Manchurian trout''',<ref name="jamescard">James Card: ''[http://jamescard.net/flyfishing/ Fly fishing in South Korea.] {{Webarchive|url=https://web.archive.org/web/20110111010149/http://jamescard.net/flyfishing/ |date=2011-01-11 }}'' Retrieved 22 June 2015.</ref> are salmonid fish of the genus '''''Brachymystax''''', native to rivers and lakes in Mongolia, Kazakhstan, wider Siberia (including Russian Far East), Northern China and Korea.<ref name="jamescard"/><ref name=Kartavtseva2013>Kartavtseva, I.V.; Ginatulina, L.K.; Nemkova, G.A.; and Shedko, S.V. (2013). ''[http://www.biosoil.ru/files/00011638.pdf Chromosomal study of the lenoks, Brachymystax (Salmoniformes, Salmonidae) from the South of the Russian Far East.] {{Webarchive|url=https://web.archive.org/web/20140729010904/http://www.biosoil.ru/files/00011638.pdf |date=2014-07-29 }}'' Journal of Species Research 2(1): 91–98.</ref><ref name="Alekseev">{{cite journal | doi = 10.1134/S0032945206070022 | last1 = Alekseev | first1 = S. S. | year = 2006 | last2 = Osinov | first2 = A. G. | title = Blunt-snouted lenoks (genus ''Brachymystax'': Salmoniformes, Salmonidae) from the Ob' basin: New data on morphology and allozyme variation | journal = Journal of Ichthyology | volume = 46 | issue = 7 | pages = 500–516 | bibcode = 2006JIch...46..500A | s2cid = 23102867 }}</ref>

==Species== There are four species in this genus, of which three are listed by FishBase:<ref name=fishbase>{{FishBase genus | genus = Brachymystax| month = September | year = 2015}}</ref> * ''Brachymystax lenok'' (Pallas, 1773) – sharp-snouted lenok<ref name=Kartavtseva2013/> * ''Brachymystax savinovi'' Mitrofanov, 1959 * ''Brachymystax tumensis'' T. Mori, 1930 – blunt-snouted lenok<ref name=Kartavtseva2013/>

A fourth species, ''Brachymystax tsinlingensis'' S. C. Li, 1966, was revalidated in 2015.<ref name=Xing2015>{{cite journal |author=Xing, Y.-C. |author2=Lv, B.-B. |author3=Ye, E.-Q. |author4=Fan, E.-Y. |author5=Li, S.-Y. |author6=Wang, L.-X. |author7=Zhang, C.G. |author8=Zhao, Y.-H. | year = 2015 | title = Revalidation and redescription of ''Brachymystax tsinlingensis'' Li, 1966 (Salmoniformes: Salmonidae) from China | journal = Zootaxa | volume = 3962 | issue = 1 | pages = 191–205 | url = http://www.mapress.com/zootaxa/2015/f/zt03962p205.pdf | doi=10.11646/zootaxa.3962.1.12| pmid = 26249386 }}</ref>

Traditionally, only ''B. lenok'' was recognized, including both sharp-snouted and blunt-snouted forms. Based on differences in morphology and genetics, the blunt-snouted form was split off as a separate species, ''B. tumensis''.<ref name=Kartavtseva2013/><ref name=Bo2007>Bo, M. A.; and Jiang, Zuo-fa (2007). ''Genetic diversity and relationship between two species of Brachymystax in Wusuli River revealed by microsatellites.'' Journal of Fishery Sciences of China 14: 39–45.</ref><ref>Balakirev, E.S.; Romanov, N.S.; and Ayala, F.J. (2014). ''Complete mitochondrial genome of blunt-snouted lenok Brachymystax tumensis (Salmoniformes, Salmonidae).'' Mitochondrial DNA 27: 1–2</ref><ref name=Froufe2008>Froufe, E.; Alekseyev, S.; Alexandrino, P.; and Weiss, S. (2008). ''The evolutionary history of sharp- and blunt-snouted lenok (Brachymystax lenok (Pallas, 1773)) and its implications for the paleo-hydrological history of Siberia.'' BMC Evolutionary Biology 8: 40. {{doi|10.1186/1471-2148-8-40|doi-access=free}}</ref> Hybrids between these two are known.<ref name=Froufe2008/> The third species, ''B. savinovi'', is sometimes considered a synonym of ''B. lenok''.<ref name=Kartavtseva2013/> The name ''B. savinovi'' has occasionally been used for the blunt-snouted lenok,<ref name=Ratschan2013>Ratschan, C. (2013). ''[http://www.ratschan.at/downloads/Lenok_ChasingSilver.pdf Trout's Siberian Siblings]''. Chasing Silver 1: 86–96.</ref> but this is incorrect.<ref name=Kartavtseva2013/><ref name=Froufe2008/>

==Appearance== Lenoks can be sharp-snouted (''B. lenok'') or blunt-snouted (''B. tumensis'').<ref name=Kartavtseva2013/><ref name=Froufe2008/> Traditionally both these were included in ''B. lenok'', but today they are generally recognized as separate. They are relatively round in shape, and speckled with dark brown spots.<ref name="jamescard"/> Their ventrals are usually colored a reddish hue, and their pectoral fins yellowish.<ref>{{cite book|title=General zoology, or Systematic natural history, Volume 5, Part 1|url=https://archive.org/details/generalzoology1121800shaw|first1=George|last1=Shaw|first2=James Francis|last2=Stephens|year=1800}}</ref> They weigh up to {{convert|15|kg}},<ref name="ibex">Ibex: {{cite web|url=http://www.ibextours.com/Eng/exclusive_salmon.htm |title=Salmon - Fishing in Siberia, Russia |access-date=2010-07-04 |archive-url=https://web.archive.org/web/20081203171330/http://www.ibextours.com/Eng/exclusive_salmon.htm |archive-date=December 3, 2008 }}</ref> and can reach a total length of {{convert|1.05|m|ft|abbr=on|1}}.<ref>{{cite web|url=http://www.fishing-worldrecords.com/scientificname/Brachymystax%20lenok/show |title=Brachymystax lenok | publisher=fishing-worldrecords.com }}</ref>

==Habitat, range and status== Lenoks tend to live in rivers of any sort, but usually upstream, where the water is colder.<ref name="cherrytrout">Cherrytrout: {{cite web|url=http://www.cherrytrout.com/fish.html |title=Fish |access-date=2010-07-04 |url-status=bot: unknown |archive-url=https://web.archive.org/web/20150204065146/http://www.cherrytrout.com/fish.html |archive-date=February 4, 2015 }}</ref> They are also found in lakes such as Baikal.<ref name=Kartavtseva2013/>

As currently defined, the sharp-snouted lenok (''B. lenok'') is widespread in central and eastern Russia, and also found widely in northern Mongolia, locally in northeastern Kazakhstan (Irtysh Basin) and northeastern China (Amur Basin).<ref name=Kartavtseva2013/><ref name=Bo2007/><ref name=Ratschan2013/> The blunt-snouted lenok (''B. tumensis'') is found widely in southeastern Russia and more locally in northeastern and central parts of the country, as well as northeastern Mongolia (Amur Basin), northern China and Korea.<ref name=Kartavtseva2013/><ref name=Ratschan2013/> Although the two generally are found in separate areas, there are also regions where their ranges overlap such as the Amur Basin.<ref name=Kartavtseva2013/><ref name="Alekseev"/><ref name=Bo2007/><ref name=Froufe2008/>

''Brachymystax savinovi'' is found in Markakol Lake and adjacent rivers in eastern Kazakhstan.<ref>{{cite iucn |author=Mamilov, N. |year=2020 |title=''Brachymystax savinovi'' |article-number=e.T156767157A156767203 |doi=10.2305/IUCN.UK.2020-3.RLTS.T156767157A156767203.en}}</ref>

The recently revalidated ''Brachymystax tsinlingensis'' is distributed in streams in the Yellow and Yangtze River basins in the Qinling Mountains of China.<ref name="Xing2015" />

Though overall widespread, lenoks in South Korea are now on the verge of extinction due to deforestation and they have also declined in China.<ref name="cherrytrout"/><ref>Yingzhe, X.; Yan, S.; and Yiyu, C. (2006). ''DNA sequence variation in the mitochondrial control region of lenok (Brachymystax lenok) populations in China.'' Chinese Biodiversity 14(1): 48–54.</ref>

==History== In the Korean peninsula, lenoks were landlocked inland during the glacial epoch.<ref name="cherrytrout"/>

==References== {{Reflist}}

== External links == * [http://www.fishing-worldrecords.com/scientificname/Brachymystax%20lenok/show A record Brachymystax lenok]

Category:Fish of Asia * Category:Taxa named by Albert Günther