The omul, ''Coregonus migratorius'', also known as Baikal omul (russian: байкальский омуль), is a whitefish species of the

salmon Salmon () is the common name for several commercially important species of euryhaline ray-finned fish from the family Salmonidae, which are native to tributaries of the North Atlantic (genus ''Salmo'') and North Pacific (genus '' Oncorhy ...

family

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 else ...

to Lake Baikal in

Siberia Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive region, 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 ...

Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eig ...

. It is considered a delicacy and is the object of one of the largest commercial fisheries on Lake Baikal. In 2004, it was listed in Russia as an endangered species.

Taxonomy

The omul has traditionally been regarded as a subspecies of the

Arctic cisco Arctic cisco (''Coregonus autumnalis''), also known as omul russian: Омуль, is an anadromous species of freshwater whitefish that inhabits the Arctic parts of Siberia, Alaska and Canada. It has a close freshwater relative in several lakes of ...

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

''. 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 eggs and sperm released or deposited into water by aquatic animals. As a verb, ''to spawn'' refers to the process of releasing the eggs and sperm, and the act of both sexes is called spawning. Most aquatic animals, except for aquat ...

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 do live on or near the bottom, and reef fish that are associated with coral re ...

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 t ...

, 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 animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by ...

, smaller fish, and occasionally some benthic 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 reproductive episode before death, and iteroparous if it is characteri ...

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 ( ; bua, Сэлэнгэ гол / Сэлэнгэ мүрэн, translit=Selenge gol / Selenge müren; russian: Селенга́, ) is a major river in Mongolia and Buryatia, Russia. Originating from its headwater tributaries, ...

, 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 (TSR; , , ) connects European Russia to the Russian Far East. Spanning a length of over , it is the longest railway line in the world. It runs from the city of Moscow in the west to the city of Vladivostok in the ea ...

, 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.

Conservation

The omul's main food source is an

species of

alga 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 ...

, '' melosira''.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