''Silurus soldatovi'', Soldatov's catfish or northern sheatfish, is a large

catfish Catfish (or catfishes; order (biology), order Siluriformes or Nematognathi) are a diverse group of ray-finned fish. Catfish are common name, named for their prominent barbel (anatomy), barbels, which resemble a cat's whiskers, though not ...

species from the

Far East The Far East is the geographical region that encompasses the easternmost portion of the Asian continent, including North Asia, North, East Asia, East and Southeast Asia. South Asia is sometimes also included in the definition of the term. In mod ...

Evolution

The earliest fossil remains of ''S. soldatovi'' are from the

Late Miocene The Late Miocene (also known as Upper Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch, which lasted from 11.63 Ma (million ye ...

of Ukraine. These remains suggest that this species had a much wider range in the past, reaching as far west as eastern Europe, although it does not appear to have expanded any further west. Although it initially coexisted with the extinct

airbreathing catfish Airbreathing catfish comprise the family Clariidae of the order Siluriformes. Sixteen genera and about 117 species of clariid fishes are described; all are freshwater species. Other groups of catfish also breathe air, such as the Callichthyidae ...

Heterobranchus austriacus ''Heterobranchus'' is a genus of airbreathing catfishes native to Africa. Depending on the exact species involved, fish of this genus reach from with the giant vundu (''H. longifilis'') being the largest completely freshwater fish in southern ...

'', it appears to have become the dominant catfish in the region during

late Miocene The Late Miocene (also known as Upper Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch, which lasted from 11.63 Ma (million ye ...

and

early Pliocene Early may refer to: Places in the United States * Early, Iowa, a city * Early, Texas, a city * Early Branch, a stream in Missouri * Early County, Georgia * Fort Early, Georgia, an early 19th century fort Music * Early B, stage name of Jamaican d ...

, potentially as a result of the Miocene climatic optimum. Afterwards, it appears to have been gradually replaced over the region by the

wels catfish The wels catfish ( or ; ''Silurus glanis''), also called sheatfish or just wels, is a large species of catfish native to wide areas of central, southern, and eastern Europe, in the basins of the Baltic, Black and Caspian Seas. It has been intro ...

(''S. glanis''), potentially due to the latter species having a wider temperature tolerance and being better adapted for the cooling trend over the Pliocene. ''S. soldatovi'' was finally extirpated from Europe by the

late Pliocene Late or LATE may refer to: Everyday usage * Tardy, or late, not being on time * Late (or the late) may refer to a person who is dead Music * Late (The 77s album), ''Late'' (The 77s album), 2000 * Late (Alvin Batiste album), 1993 * Late!, a pseudo ...

Description

This catfish is visually similar to the closely related

Wels catfish The wels catfish ( or ; ''Silurus glanis''), also called sheatfish or just wels, is a large species of catfish native to wide areas of central, southern, and eastern Europe, in the basins of the Baltic, Black and Caspian Seas. It has been intro ...

. Soldatov's catfish has a large flat head. Its mouth is blunt and rounded, the upper jaw shorter than the lower jaw. Barbels are located on the upper jaw and chin. It has the following formula fins: dorsal six soft rays, anal 83–90 soft rays. The fish can live up to 20 years, and can grow to about 4 meters in length and weigh 40 kilograms.

Etymology

The fish is named in memory of

Vladimir Konstantinovich Soldatov Vladimir Konstantinovich Soldatov (, 15 July 1875 – 31 January 1941) was a Russian and Soviet ichthyologist, zoologist, Doctor of Biological Sciences, professor of the Department of Ichthyology of the Moscow Technical Institute for the Fishery I ...

(1875–1941), the preeminent authority on the Amurian fishes.

Distribution and habitat

Soldatov's catfish lives in

Amur River The Amur River () or Heilong River ( zh, s=黑龙江) is a perennial river in Northeast Asia, forming the natural border between the Russian Far East and Northeast China (historically the Outer and Inner Manchuria). The Amur ''proper'' is ...

(

Ussuri The Ussuri ( ; ) or Wusuli ( ) is a river that runs through Khabarovsk and Primorsky Krais, Russia and the southeast region of Northeast China in the province of Heilongjiang. It rises in the Sikhote-Alin mountain range, flowing north and formi ...

) in Russia and China. It prefers water temperatures from 5 to 25 °C. As suggested by fossil remains, it reached as far west as modern Ukraine during the warmer

Threats

The Soldatov's catfish population is threatened by overfishing, habitat degradation and water pollution. Due to its localized distribution and the low population density, the population is now considered endangered.

References

External links

Picture of ''Silurus soldatovi''
{{Taxonbar, from=Q2442659 Silurus Fish of East Asia Freshwater fish of China Fish of Russia Taxa named by Georgii Vasil'evich Nikolskii Taxa named by Sergey Gavrilovich Soin Fish described in 1948 Miocene fish of Europe