The Baikal yellowfin (''Cottocomephorus grewingkii''), also known as the yellow-finned sculpin or yellow-wing sculpin, is a species of freshwater

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species. The ray-finned fishes are so called because their fins are webs of skin supported by bony or hor ...

belonging to 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 ...

Cottidae The Cottidae are a family of fish in the superfamily Cottoidea, the sculpins. It is the largest sculpin family, with about 275 species in 70 genera.Kane, E. A. and T. E. Higham. (2012)Life in the flow lane: differences in pectoral fin morphology ...

, the typical sculpins. This species is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

Lake Baikal Lake Baikal (, russian: Oзеро Байкал, Ozero Baykal ); mn, Байгал нуур, Baigal nuur) is a rift lake in Russia. It is situated in southern Siberia, between the federal subjects of Irkutsk Oblast to the northwest and the Repu ...

and its tributaries in

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 ...

, Russia. It is most common in the southern part of the lake and lives from near the shore to a depth of .

Appearance

It can reach up to in total length, but most are . They have relatively large

pectoral fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as ...

s, which are yellow in males. During the breeding season, the male's head becomes black when encountering other males.

Behavior

The Baikal yellowfin feeds on

copepod Copepods (; meaning "oar-feet") are a group of small crustaceans found in nearly every freshwater and saltwater habitat (ecology), habitat. Some species are planktonic (inhabiting sea waters), some are benthos, benthic (living on the ocean floor) ...

s (notably ''

Epischura baikalensis ''Epischurella baikalensis'' (previously ''Epischura baikalensis'') is a species of copepod in family Temoridae. It is endemic to Lake Baikal, being the dominant zooplankton species there: 80%–90% of total biomass. It measures . ''Epischurella ...

''),

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 9,900 amphipod species so far descr ...

s, insect larvae and fish larvae. There are three separate breeding periods: March, May and August. There are some differences in the breeding behavior and site depending on when the fish breeds. Breeding occurs at a depth of in a crevice under a rock, which measures from to . The distance between the rock's flat underside and the bottom is preferably . The female lays 389 to 3136 eggs on the underside of the rock (upperside of the crevice), which are guarded by the male and if he disappears, the eggs usually perish. The eggs hatch after 15–20 days at a water temperature of , and 20–24 days at . After hatching, the fish larvae initially survive off their

yolk sac The yolk sac is a membranous sac attached to an embryo, formed by cells of the hypoblast layer of the bilaminar embryonic disc. This is alternatively called the umbilical vesicle by the Terminologia Embryologica (TE), though ''yolk sac'' is far ...

and then start feeding on copepods. The Baikal yellowfin can reach an age of up to six years and reach sexual maturity when two or three.

Status and threats

Young Baikal yellowfins are important food for other fish such as the

omul The omul, ''Coregonus migratorius'', also known as Baikal omul (russian: байкальский омуль), is a whitefish species of the salmon family endemic to Lake Baikal in Siberia, Russia. It is considered a delicacy and is the object of ...

. Until the 1950s and 60s, the Baikal yellowfin was fished in large numbers, but it declined and is not commercially fished anymore. A prime reason for the decline was the

Irkutsk Hydroelectric Power Station The Irkutsk Hydroelectric Power Station (Irkutsk HPS) is a rock-fill dam on the Angara River with an adjacent hydroelectric power station. It is located adjacent to Irkutsk, Irkutsk Oblast in Russia and is the first dam on the Angara cascades. Con ...

, which caused siltation of the breeding grounds. Another threat are

algal Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular mic ...

mats ('' Spirogyra'' and ''

Ulothrix ''Ulothrix'' is a genus of green algae in the family Ulotrichaceae. ''Ulothrix'' is a genus of non-branching filamentous green algae, generally found in fresh and marine water. Its cells are normally as broad as they are long, and they thrive i ...

''), which during blooms may cover their breeding grounds.

References

{{Taxonbar, from=Q2591239 Baikal yellowfin Fish of Lake Baikal Freshwater fish of Asia Taxa named by Benedykt Dybowski Baikal yellowfin