4 species of Taimen inhabit in Eurasia. One of them, Hucho Taimen inhabits in the crystal clear waters of Mongolia and it is the biggest fish in Mongolia. The recorded biggest one was up to 2 m and weighed over 70 kg. Hucho Taimen is distributed throughout the country in the Rivers Kherlen, Tenghis, Shishgid, Selenge, Delger, Ider, Orkhon, Onon, Tuul, Chuluut, Khalkha, Suman and many other smaller rivers, Lake Ogii, Buir, Terkhiin Tsagaan and as well as lakes of the Darkhad Depression. They dwell at the deepest and coolest pools of fast flowing clear rivers that is rich in oxygen. In springs Taimen ascends rivers due to their reproductive activities and descends the rivers in autumn to lakes for winter. This is connected directly to the temperature of waters and food.

Taimen of the River Kherlen hunts about 200–250 km from the source in summers till late September and descends the river later on then for winter. Taimen start mating at 5-6 when they are 35-40 cm in length. They spawn in the second half of May at river gravels, at water temperature 10’C. Major food for Taimen is fish and water animals. Mostly, Amur dace, Bitterling, Minnow, Gudgeon and so on are food for Taimen.

During reproductive periods Taimen don’t eat much, then they seek for food so eagerly until mid summer. Then they again eat a lot in autumn. The competitors of food for Taimen are Lenok, Pike, River perch, Look up and Mongolian redfin. The Taimen in Mongolia, however, has been decreasing.

LENOK
Lenok is golden brown or golden brownish colored and distributed in Rivers Kherlen, Tenghis, Shishgid, Selenge, Delger, Ider, Orkhon, Onon, Tuul, Chuluut, Khalkha, Suman and many other smaller rivers, Lake Huvsgul, Ogii, Buir, Terkhiin Tsagaan and as well as rivers and lakes of the Darkhad Depression. Their living biotope is similar to Taimen’s or they live in cool and clear rivers and lakes rich in oxygen. The distribution of Lenok of the river Kherlen is changed consequently. They live in the deep in rivers. They spawn at water temperature of 20’C, and are considered as slow reproducing fish. Lenok is a main food competitor of Taimen, Pike, Burbot and Grayling.