The omul, ''Coregonus migratorius'', also known as Baikal omul (), is a

whitefish Whitefish or white fish may refer to: Fish * Whitefish (fisheries term), referring to species commercially caught in the North Atlantic * Freshwater whitefish, members of the subfamily Coregoninae in the family Salmonidae, including: ** Atlant ...

species of the

salmon Salmon (; : salmon) are any of several list of commercially important fish species, commercially important species of euryhaline ray-finned fish from the genera ''Salmo'' and ''Oncorhynchus'' of the family (biology), family Salmonidae, native ...

family

endemic Endemism is the state of a species being found only 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 foun ...

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 ...

Siberia Siberia ( ; , ) is an extensive geographical region comprising all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has formed a part of the sovereign territory of Russia and its predecessor states ...

Russia Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

. It is considered a delicacy and is the object of one of the largest commercial fisheries on Lake Baikal.

Taxonomy

The omul has traditionally been regarded as a subspecies of the

Arctic cisco The Arctic cisco (''Coregonus autumnalis''), also known as Arctic omul (), is an anadromy, anadromous species of freshwater whitefish that inhabits the Arctic parts of Siberia especially Yenisey Gulf. It can also be found in Alaska and Canada. I ...

''Coregonus autumnalis''. However, recent genetic studies have shown it actually belongs to the circumpolar ''

Coregonus lavaretus ''Coregonus lavaretus'' is a species of freshwater whitefish, in the family Salmonidae. It is the type species of its genus '' Coregonus''. There are widely different concepts about the delimitation of the species ''Coregonus lavaretus'' and abo ...

- clupeaformis'' complex of lake whitefishes, which also has other members in Lake Baikal, and it is now considered its own species within ''

Coregonus ''Coregonus'' is a diverse genus of fish in the salmon family (Salmonidae). The ''Coregonus'' species are known as whitefishes. The genus contains at least 68 described extant taxa, but the true number of species is a matter of debate. The type ...

''. The four or five traditionally accepted subpopulations of omul within Lake Baikal are: North Baikal (северобайкальский), Selenga (селенгинский), Chivyrkui (чивыркуйский) and Posolsk (посольский). These vary in size, feeding behaviors and preferred

spawning Spawn is the Egg cell, eggs and Spermatozoa, sperm released or deposited into water by aquatic animals. As a verb, ''to spawn'' refers to the process of freely releasing eggs and sperm into a body of water (fresh or marine); the physical act is ...

habitats. The extent of their reproductive isolation is debated.

Description

The omul is a slender,

pelagic fish Pelagic fish live in the pelagic zone of ocean or lake waters—being neither close to the bottom nor near the shore—in contrast with demersal fish that live on or near the bottom, and reef fish that are associated with coral reefs. ...

with light silver sides and a darker back. It has small spots on its dorsal fin and larger ones on its head, a terminal mouth position and a large number of

gill rakers Gill rakers in fish are bony or cartilaginous processes that project from the branchial arch (gill arch) and are involved with suspension feeding tiny prey. They are not to be confused with the gill filaments that compose the fleshy part of the ...

, typical of fish that feed in the pelagic zone. The mean size of adults is 36–38 cm and 0.6 to 0.8 kg, though the maximum reported length is 56 cm weighing about 2.5 kg. The subpopulations on the northern end of the lake tend to be smaller.

Behavior

The omul feeds primarily on

zooplankton Zooplankton are the heterotrophic component of the planktonic community (the " zoo-" prefix comes from ), having to consume other organisms to thrive. Plankton are aquatic organisms that are unable to swim effectively against currents. Consequent ...

, smaller fish, and occasionally some

benthic The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from the Ancient Greek word (), meaning "the depths". ...

organisms. It feeds primarily in the rich pelagic zone of Lake Baikal up to 345–450 m. It is a relatively long-lived,

iteroparous Semelparity and iteroparity are two contrasting reproductive strategies available to living organisms. A species is considered ''semelparous'' if it is characterized by a single reproduction, reproductive episode before death, and ''iteroparous ...

species that attains reproductive maturity at five to 15 years of age. The omul only enters the rivers that feed Lake Baikal to spawn, like the

Selenga 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 d ...

, initiating short spawning migrations, usually in mid-October, broadcasting 8000–30000 eggs before returning to the lake.

Consumption and fishery

Omul is one of the primary food resources for people living in the Baikal region. It is considered a delicacy throughout Russia, and export to the west is of some economic importance. Smoked omul is widely sold around the lake and is one of the highlights for many travelers on the

Trans-Siberian railway The Trans-Siberian Railway, historically known as the Great Siberian Route and often shortened to Transsib, is a large railway system that connects European Russia to the Russian Far East. Spanning a length of over , it is the longest railway ...

, and locals tend to prefer the fish salted. A popular Siberian salad called ''stroganina'' consists of uncooked frozen omul shaved thinly and served with pepper, salt and onion. Due to its high demand, the omul is the object of one of the most important commercial fisheries in Lake Baikal. The highest recorded annual landed catches occurred in 1940s and amounted to 60-80 thousand tonnes. A subsequent crash in the population led to a closing of the fishery in 1969, followed by a reopening with strict quotas in 1974 after some recovery of the stocks.Galazin, G.I. (1978) Рыбные ресурсы Байкала и их использование (Fish resources of Baikal and their exploitation). ''Problemy Baikala'', Siberian Division of the Russian Academy of Sciences, Novosibirsk, v. 16 (36).'' (in Russian

/ref> Currently, the omul fishery accounts for roughly two-thirds of the total Lake Baikal fishery. Fluctuations in the population and intensive fishing make sustaining the fishery one of the highest priorities for local fisheries managers.

Diet

The omul's main food source is an

species of

alga Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular microalgae, suc ...

, ''

Melosira ''Melosira'' is a genus of diatoms belonging to the family Melosiraceae. The genus has cosmopolitan distribution, and inhabits both freshwater and marine habitats. ''Melosira'' is considered as meroplankton, as they remain free-floating like ...

''.Lonely Planet Trans-Siberian Railway
/ref>

Gallery

Freshly caught Baikal omul.jpg, Freshly caught Baikal omul Baikal omul.jpg, Baikal omul Baikal smoked omul on the counter of the store.jpg, Baikal cold-smoked omul on the counter of the store Omul on a cutting board.jpg, Omul on a cutting board

References

External links

* {{Taxonbar, from=Q82572 Coregonus Fish of Lake Baikal Fish described in 1775 Taxa named by Johann Gottlieb Georgi