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.
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.
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
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.
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.
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.