''Thymallus baicalensis'', also known as the Baikal black grayling, is a Siberian

freshwater fish Freshwater fish are fish species that spend some or all of their lives in bodies of fresh water such as rivers, lakes, ponds and inland wetlands, where the salinity is less than 1.05%. These environments differ from marine habitats in many wa ...

species in the salmon

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Salmonidae Salmonidae (, ) is a family (biology), family of ray-finned fish, the only extant member of the suborder Salmonoidei, consisting of 11 extant genera and over 200 species collectively known as "salmonids" or "salmonoids". The family includes salmo ...

. ''Thymallus baicalensis'' occurs in

Lake Baikal Lake Baikal is a rift lake and the deepest lake in the world. It is situated in southern Siberia, Russia between the Federal subjects of Russia, federal subjects of Irkutsk Oblast, Irkutsk Oblasts of Russia, Oblast to the northwest and the Repu ...

, in the inflowing

Selenga River The Selenga ( ) or Selenge is a major river in Mongolia and Buryatia, Russia. Originating from its headwater tributaries, the Ider and the Delger mörön, it flows for before draining into Lake Baikal. The Selenga therefore makes up the most ...

and throughout the major

Enisei River The Yenisey or Yenisei ( ; , ) is the fifth-longest river system in the world, and the largest to drain into the Arctic Ocean. Rising in Mungaragiyn-gol in Mongolia, it follows a northerly course through Lake Baikal and the Krasnoyarsk Dam be ...

drainage, and also some eastern tributaries of the

Ob River The Ob (; ) is a major river in Russia. It is in western Siberia, and with its tributary the Irtysh forms the world's seventh-longest river system, at . The Ob forms at the confluence of the Biya and Katun which have their origins in the Alta ...

.Weiss, S. J., D. V. Gonçalves, G. Secci-Petretto, G. K. Englmaier, A. Gomes-Dos-Santos, G. P. J. Denys, H. Persat, A. Antonov, C. Hahn, E. B. Taylor and E. Froufe (2021) Global systematic diversity, range distributions, conservation and taxonomic assessments of graylings (Teleostei: Salmonidae; ''Thymallus'' spp.). ''Organisms Diversity & Evolution'': published online on 25 Nov. 2020. It was previously considered a subspecies of 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 Missou ...

, ''Thymallus arcticus baicalensis'', but currently one of several distinct Siberian and East Asian grayling species, the closest of which are '' Thymallys nikolskyi, T. svetovidovi, T. brevicephalus '' and ''T. brevirostris''. The distinction of these taxa is supported by the phylogeny of their

mitochondrial DNA Mitochondrial DNA (mtDNA and mDNA) is the DNA located in the mitochondrion, mitochondria organelles in a eukaryotic cell that converts chemical energy from food into adenosine triphosphate (ATP). Mitochondrial DNA is a small portion of the D ...

lineages. ''T. baicalensis'' is also characterized by a distinct dorsal-fin colouration pattern. The Baikal grayling can grow up to a length 38 cm and 1.2 kg weight. It mainly moves along stony bottoms at shallow depths, feeding on

caddisfly The caddisflies (order Trichoptera) are a group of insects with aquatic larvae and terrestrial adults. There are approximately 14,500 described species, most of which can be divided into the suborders Integripalpia and Annulipalpia on the basis ...

and

stonefly Plecoptera is an order of insects commonly known as stoneflies. Some 3,500 species are described worldwide, with new species still being discovered. Stoneflies are found worldwide, except Antarctica. Stoneflies are believed to be one of the most ...

larvae,

amphipod Amphipoda () is an order of malacostracan crustaceans with no carapace and generally with laterally compressed bodies. Amphipods () range in size from and are mostly detritivores or scavengers. There are more than 10,700 amphipod species cur ...

crustaceans and fish eggs.

References

{{Taxonbar, from=Q3768305 baicalensis Freshwater fish of Asia Fish of Lake Baikal