Fish Facts: Siberian Taimen (Hucho taimen)

A true river monster, the taimen (Hucho taimen)—also known as the Siberian taimen—can grow to proportions that seem incredible to your average trout fishermen. Whereas John Gierach once wrote about “trout as long as your leg,” taimen can grow as long as your whole body, over six feet, and the largest recorded specimen weighed in at 231 pounds! Armed with stout fly rods and foot-long, articulated streamers, fly fishers in Mongolia or Russia can spend days looking for a taimen willing to feed, but once a fish makes up its mind, it chases down its prey with remarkable speed and aggression. If the angler’s skills are up to the task, he or she will end up cradling a trophy of a lifetime.

Range and Species History

The original range of the Siberian taimen spans from the Upper Volga River basin in far western Europe to the Pacific drainages of the Amur River in China, which is also the southern boundary. To the north, the species can be found in the Pechora and Yana Rivers, which empty into the Arctic Ocean. The taimen’s native range has seen some reduction along the western slope of the Aral Mountains, as well as in Mongolia and China, but overall taimen continue to inhabit the vast majority of their native range, albeit in much reduced numbers.

Taimen anglers are passionate about preserving habitat and promoting catch and release.
Photo courtesy Mongolia River Outfitters

Taimen are potamodromous, which means that they spend their entire lives in freshwater, usually in swift-flowing rivers with high oxygen levels, and they often move up- and downstream extensively. Using telemetry equipment, fisheries biologists recorded one taimen inhabiting a home range of almost 60 river miles throughout the year. Spawning generally occurs in late May or June, depending on water temperature. The fish travel upstream to smaller tributaries, where spawning occurs, and then drop back into the larger rivers.

Siberian taimen do not spawn until they are five to seven years old and can live for decades. Although some sources put the species’ life span at a conservative 30 years, others claim that taimen can live for half a century or more. Because of where they live and how relatively few fish there are in a given location, the species has not been extensively studied, which accounts for some of the variance in “life facts.” Adult fish are also generally solitary, as well, which increases the difficulty of observation.

The largest reliably recorded specimen, caught in Russia’s Kotui River in 1943, measured an astonishing 83 inches long and weighed 231 pounds. The IGFA all-tackle record was a relative minnow, at 92 pounds, 8 ounces. A 50-incher is considered a true trophy, and fly fishers land Siberian taimen that large every year in Mongolia and Russia. It anglers’ desire to experience landing such a river monster that may ensure the species’ survival.

Close Relations

There are four recognized members of the Hucho genus, the others being the huchen or Danube salmon (Hucho hucho); the Sichuan taimen (Hucho bleekeri); and the Korean taimen (Hucho ishikawae). The Sakhalin or Japanese taimen, formerly known as Hucho perryi, was reclassified into its own genus and is now Parahucho perryi. The Siberian taimen and huchen are impossible to distinguish visually, but because they inhabit non-overlapping ranges separated by the flatlands of central Asia, they are distinguished by geography. None of the other species reach the same proportions of an adult Siberian taimen, but the huchen can grow to almost five feet long and weigh over 100 pounds. The others are more trout-size, topping out at 20 to 26 inches.

Threats and Conservation Efforts

Throughout its range, the Siberian taimen has suffered from habitat loss, reduction of water quality, overgrazing, damming, and poaching. Because these fish are slow-growing–they take up to seven years to reach sexual maturity–populations can’t bounce back very quickly, and the taimen is listed as “vulnerable” on the “Red List” maintained by the International Union for Conservation of Nature. According to their research, taimen populations have declined by between 50% and 95%, depending on location, with the worst losses in China and the most stable populations in Russia’s arctic drainages. Mongolia has been the most progressive in its conservation efforts, introducing catch-and-release regulations on all rivers and working with local outfitters to build awareness of how important healthy taimen populations can be to local economies. Enforcement of anti-poaching laws remains a problem, however.

Gear and Flies

Siberian taimen are big fish, and you’ll need gear to match. Most anglers use single-hand or switch rods in weights 8 or 9 with a reel capable of holding 200 yards of backing and featuring a drag system capable of slowing down a 60-pounder. Because the fish tend to attack their prey near the surface, there is little “dredging”: the standard line is a weight-forward floater, although it pays to bring a multi-tip sinking line system, as well. Ten foot leaders tapering to 0X or 20-pound-test will allow you to really put the wood to a fish and bring it to hand as quickly as possible.

Believe it or not, taimen will hit dry flies, but not reliably. Large, splashy surface patterns, such as mice and baitfish poppers and sliders, trigger the fish’s predatory response. However, Siberian taimen are mostly pisciverous, so large streamers that imitate fleeing baitfish produce best.