''Thymallus yaluensis'' is a putative

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include ...

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of li ...

, a

grayling Grayling or Greyling may refer to: Animals Fish * Grayling, generically, any fish of the genus ''Thymallus'' in the family Salmonidae ** European grayling (''Thymallus thymallus''), the European species of the genus ''Thymallus'' ** Arctic grayli ...

in the

salmon Salmon () is the common name for several list of commercially important fish species, commercially important species of euryhaline ray-finned fish from the family (biology), family Salmonidae, which are native to tributary, tributaries of the ...

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Salmonidae Salmonidae is a family of ray-finned fish that constitutes the only currently extant family in the order Salmoniformes . It includes salmon (both Atlantic and Pacific species), trout (both ocean-going and landlocked), chars, freshwater whitefis ...

. It is endemic to the upper

Yalu River The Yalu River, known by Koreans as the Amrok River or Amnok River, is a river on the border between North Korea and China. Together with the Tumen River to its east, and a small portion of Paektu Mountain, the Yalu forms the border between ...

Korea Korea ( ko, 한국, or , ) is a peninsular region in East Asia. Since 1945, it has been divided at or near the 38th parallel, with North Korea (Democratic People's Republic of Korea) comprising its northern half and South Korea (Republic o ...

, on the

Chinese Chinese can refer to: * Something related to China * Chinese people, people of Chinese nationality, citizenship, and/or ethnicity **''Zhonghua minzu'', the supra-ethnic concept of the Chinese nation ** List of ethnic groups in China, people of va ...

border. ''Thymallus yaluensis'' is a small fish, the maximum recorded length is 20 cm (8 in). "It has the most beautiful form and fins of a freshwater fish" in Korea. Some confusion exists about the identity of ''T. yaluensis.'' It is very similar in form to the

Arctic grayling The Arctic grayling (''Thymallus arcticus'') is a species of freshwater fish in the salmon family Salmonidae. ''T. arcticus'' is widespread throughout the Arctic and Pacific drainages in Canada, Alaska, and Siberia, as well as the upper Misso ...

''T. arcticus'', and has mostly been treated as a subspecies, ''T. a. yaluensis'', although

FishBase FishBase is a global species database of fish species (specifically finfish). It is the largest and most extensively accessed online database on adult finfish on the web.

treats it as an independent species. According to

mitochondrial DNA Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, such as adenosine triphosphate (ATP). Mitochondrial D ...

, it is, however, inseparable from the Amur grayling ''T. grubii'', and was suggested to be a

junior synonym The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently. * In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linna ...

of that.MA Bo, HUO Tang-Bin, JIANG Zuo-Fa (2008
''Thymallus arcticus yaluensis'' is a synonym of ''T. grubii'' by mitochondrial control region sequences analysis.
Acta Zootaxonomica Sinica 33 (2) Confusingly, it has also been reported from widely separate regions including

Siberia Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a part of ...

, the

Alps The Alps () ; german: Alpen ; it, Alpi ; rm, Alps ; sl, Alpe . are the highest and most extensive mountain range system that lies entirely in Europe, stretching approximately across seven Alpine countries (from west to east): France, Sw ...

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

, and the northern

Mississippi River The Mississippi River is the second-longest river and chief river of the second-largest drainage system in North America, second only to the Hudson Bay drainage system. From its traditional source of Lake Itasca in northern Minnesota, it f ...

drainage in

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

References

{{Taxonbar, from=Q3767625 Thymallus Taxa named by Tamezo Mori Fish described in 1928