Omul

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Omul

Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Salmoniformes
Family: Salmonidae
Genus: Coregonus
Species: C. migratorius

The omul, Coregonus migratorius, also known as Baikal omul (Russian: байкальский омуль), is a relatively abundant whitefish species of the salmon family endemic to Lake Baikal in Siberia, Russia. It is considered a delicacy and is the object of one of the largest commercial fisheries on Lake Baikal.

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[edit] Taxonomy

The omul has traditionally been regarded as a subspecies of the Arctic cisco Coregonus autumnalis. However, recent genetic studies have shown that it actually belongs to the circumpolar Coregonus lavaretus-clupeaformis complex of lake whitefishes, which also has other members in Lake Baikal,[1] and it is now considered its own species within Coregonus.[2] There are four or five traditionally accepted subpopulations within Lake Baikal: North Baikal (северобайкальский), Selenga (селенгинский), Chivurk (чивыркуйский) and Posol (посольский). These vary in size, feeding behavior and preferred spawning habitats. The extent of their reproductive isolation is debated.

[edit] Physical description and behavior

The omul is a slender pelagic fish 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 and a large number of gill rakers, typical of fish that feed in the pelagic zone.[1] The mean size of adults is 36-38 cm and 0.6 to 0.8 kg, though there are maximum reported lengths of 56 cm[3] weighing about 2.5 kg. The subpopulations on the northern end of the lake tend to be smaller.

The omul feeds primarily on zooplankton, smaller fish and occasionally some benthic organisms. It feeds primarily in the rich pelagic zone of Lake Baikal up to 345-450 m. They are a relatively long-lived, 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, initiating short spawning migrations usually in mid-October, broadcasting 8000-30000 eggs before returning to the lake.

Omul Fish at the Listvyanka market.
Omul Fish at the Listvyanka market.

[edit] 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, though locals tend to prefer the fish salted. A popular Siberian salad called stroganina consists of uncooked frozen omul cut finely and served with pepper, salt and onion.

Due to its high demand and relative abundance, the omul is the object of one the most important commercial fisheries in Lake Baikal. The highest recorded annual landed catches occurred in the 1940's and amounted to 60-80 thousand tonnes.[4] 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.[5] Currently, the omul fishery accounts for roughly two thirds of the total Lake Baikal fishery.[6] Fluctuations in the population and intensive fishing make sustaining the fishery one of the highest priorities for local fisheries managers.

[edit] References

  1. ^ a b Sukhanova, L.V. et al. (2004). "Grouping of Baikal Omul Coregonus autumnalis migratorius Georgi within the C. lavaretus complex confirmed by using a nuclear DNA marker". Ann. Zool. Fenn. 41: 41–49. 
  2. ^ Coregonus migratorius (TSN 161933). Integrated Taxonomic Information System. Retrieved on 30 January 2006.
  3. ^ "Coregonus migratorius". FishBase. Ed. Ranier Froese and Daniel Pauly. 1 2008 version. N.p.: FishBase, 2008.
  4. ^ Research-Educational Center “Baikal“: FAQ [1]
  5. ^ Galazin, G.I. (1978) Рыбные ресурсы Байкала и их использование (Fish resources of Baikal and their explotation). Problemy Baikala, Siberian Division of the Russian Academy of Sciences, Novosibirsk, v. 16 (36). (in Russian) [2]
  6. ^ Ye.I. Buyanova (2002) Экология рыбного хозяйства бассейна озера Байкал (Ecology of commercial fisheries on Lake Baikal), MSU, Moscow, 2002. (in Russian) [3]