Date of this Version
Erforschung biologischer Ressourcen der Mongolei (2016) band 13: 271-279.
Introductions and subsequent acclimatization of the fish Baicalian omul (Coregonus autumnalis migratorius natio possolskii) was carried out in 1980, 1982, and 1986 in the previously fishless lakes of Ulaagchnii Khar, Baga, and Jaahan located in the territory of Gobi region of the Zavhan administrative aimag of Mongolia. Three million larvae of Coregonus autumnalis migratorius natio possolskii were received from the Bolshrechnsky fishery in Buryatya, Russia (DULMAA 1999). The density of distribution was 10-15 thousand units per hectare with an average larvae mass of 0.05 g. The relatively abundant fodder base has facilitated the high rate of growth and quick maturity (within 4 -5 years). This is related to the specific features of nutrition of Baicalian omul of different size groups. The main food for young fish were the copepods Mixodiaptomus incrassatus, Arctodiaptomus bacillifer, and Cyclops abyssorum, which build up to maximum numerical densities in July-August of each year. Fish feeding on these copepods accumulate reddish spots on their skin with a biomass of 6.99-10.1 m3. The trophic relationship of the Baicalian omul indicate that chironomid midge larve are consumed by all age classes of fish, which also feed on amphipods, larvae of other water insects, molluscs and ostracods. Populations of fish spawn in the area of underwater spring sources. Therefore, it appears that the Baicalian omul has acclimatized well in the system of the lake Ulaagchnii Khar and has spread to all areas of the lake.