The taimen (Hucho taimen) is one of 5 species in the genus Hucho, which includes Hucho hucho, H. perriyi, and H. ishikawai, and H. bleekeri. A very large fish, it once attained a maximum of over 2 meters and 100 kilograms. In recent times reports of fish above 50 kilograms and 160 centimeters are rare. Taimen occur predominantly in river environments, preferring fast moving rivers and streams.

DISTRIBUTION

The taimen is distributed from the Volga and Pechora River basins east to the Yana River in the north and that of the Amur River in the south. On a larger scale, this includes parts of the Caspian and Arctic drainages in Eurasia and portions of the Pacific drainage in Mongolia and Russia (the Amur River). In Mongolia the taimen is found in both the Arctic and Pacific drainages, specifically the Yenisei, the Selenga/Lena, and the Amur River Basins.

MIGRATION

Very little information exists about taimen spawning behavior. In general, taimen are thought to migrate short distances in spring and autumn. In spring, during spawning, taimen migrate from larger, deeper rivers to smaller, shallower streams, usually side tributaries of about 50-150 centimeters in depth. In autumn, taimen are believed to migrate downstream to deeper river stretches to feed. Taimen migrations of 10-40 kilometers have been reported, though in general taimen migrations may be shorter - Vokac (1959) reported that large taimen do not migrate more than 1-2 kilometers per year.

DIET

The taimen is a top predator, feeding on smaller fishes and also amphibians, small mammals and birds. Though taimen have been known to feed on over 50 species of fish, the diet of taimen is dependent on the species composition of the particular stream inhabited. In the Eg-Uur system, the taimen diet appears to be mainly grayling and the minnow Phoxinus phoxinus.

REPRODUCTION

Taimen reach sexual maturity at approximately 5-7 years of age and at a size of 60-70 centimeters and 2-3 kilograms. Females produce 10,000 - 30,000 eggs, depending on the size of the fish. Spawning usually takes place in April or May. The time of spawning seems to be determined mainly by water temperature. The total duration of the spawning season at any given location is reported at between 7-14 days.

CONSERVATION STATUS

The taimen is not listed as endangered on the IUCN Red List but is listed in the Russian and Mongolian Red Books. This indicates that the fish is threatened across much of its range. Threats to the taimen include over-fishing, pollution, and habitat destruction.