Siberian taimen (Hucho taimen)
The range of Siberian taimen covers northeastern Europe and almost all of Northern Asia: the watersheds of big Siberian rivers flowing into the Polar Ocean — from the Ob River in the west to the Yana River in the east. Taimen range includes also rivers that drain into the southwestern part of the Sea of Okhotsk, including the huge Amur River. The European part of the species range is situated on the western slopes of the Ural Mountains and includes eastern tributaries to the Volga and Pechora drainages. Not long ago this fish was also discovered in the northwest of Sakhalin Island. Outside Russia, Siberian taimen are also present in Northern China and in Mongolia.
Taimen body is dark, mostly gray or gray-brown with a white or reddish belly and multitude of small, black, x-shaped or crescent-shaped dots. The ventral and pectoral fins are dark red. The spawning fish are brightly colored, with the prevalence of copper and red, especially in the rear part of the body. The black dots of taimen in the Far East are much smaller compared with fish from Mongolia.
Siberian taimen can be huge and weigh over 90 kg; there is even data on a 210 cm, 105 kg giant, caught in 1943 in the Kotui River (east from the Taimyr Peninsula, northern Siberia). The only serious rival of this fish among salmonids is the anadromous Sakhalin taimen. In comparison, the biggest recorded Chinook was much smaller — 62 kg; the biggest specimens of Atlantic salmon, sea-trout or North-American lake trout barely exceed 50 kg.
Surely, taimen only reach such impressive size in big waters rich in food — and in areas where there are few of the most dangerous predators, humans. Very big specimens, weighing over 50–60 kg, were landed during the last 10–15 years in the Tugur, Uda, and Anyi Rivers (Khabarovski Krai). All these drainages host big stocks of chum salmon. It is obvious that salmon in the river are easy prey for big taimen.
Siberian taimen are strictly freshwater, mostly river-resident fish. They are also found in some clear, mountainous lakes, populated by salmonids and whitefishes. Taimen normally make short or long migrations within the river drainage. A typical annual cycle includes wintering, spring spawning run and spawning, summer feeding, and downstream migration to the wintering places in the fall. Taimen spend winters in big rivers actively feeding under the ice. The upstream spawning migration begins with the spring flow increase, in April or May. As a rule, taimen from big rivers enter tributaries of the first or second order. This species prefers streams of mountainous or piedmont type at least 40 km long. Taimen spawn in tailouts with gravel bottoms from mid-May through mid-June. The timing of the downstream migration back into the main river depends on the size of the spawning tributary and on the speed of decrease of the water level. In bigger streams with sufficient water discharge and deep pools, taimen stay to feed through the whole summer and fall. The downstream wintering migration occurs during the freezing period and ice-flood. In the Amur River drainage taimen often spend winter in the main river, but in the summer they are always far from it, in cool mountainous streams.
Siberian taimen grow rather fast. By the age of ten they often reach 90–100 cm and weigh 7–10 kg. Henceforward they can grow even faster. Annual growth in different rivers differs depending on climate and food abundance. The maximum recorded taimen age was 55 years, but in theory this fish can reach the age of 100 years. A trophy fish can be older than the fisherman!
Taimen is a freshwater tiger. A grown fish has no enemies except humans, and it can live for decades. Like tigers in the taiga, there can not be many taimen in the river – large predators need a lot of food. This fish matures late – with a length of more than 60 centimeters and at least 7 years old. Therefore, in places where people often visit, taimen disappear first – faster than other fish. This has already happened in many rivers of not so densely populated Siberia. The only way to save this beautiful fish is to start releasing it. This is the ony way to save this great fish!