Taimen (Hucho taimen) is the world’s largest salmonid and a prized sport fish. Potential threats to Salmonids include habitat loss caused by mining activities, water diversion, pollution, changes in land use and human exploitation, including poaching. Taimen is currently listed as endangered in Mongolia. Taimen is a highly specialized predator and plays an indispensable role in the structure of fish communities in Onon River. We used data which collected September of 2014, catch-release fishing by recreational fisherman of “Nomadic Journeys” company in Onon River. A total of 83 taimen ranging in size from 37 cm to 122 cm, and taimen girth in size from 34 cm to 47 cm. Management of taimen throughout their remaining range is hampered by a general lack of knowledge about the life history and population dynamics of this species.
