The tiger trout (Salmo trutta X Salvelinus fontinalis) is a sterile, intergeneric hybrid of the brown trout (Salmo trutta) and the brook trout (Salvelinus fontinalis). The name derives from the pronounced vermiculations, evoking the stripes of a tiger. It is a rare phenomenon in the wild, with the brook trout having 84 chromosomes and the brown trout 80. Records show instances as far back as 1944. The cross itself is unusual in that the parents are members of different genera.
Tiger trout can be produced reliably in hatcheries. This is done by fertilizing brown trout eggs with brook trout milt and heat shocking them, which causes creation of an extra set of chromosomes and increases survival from 5% to 85%. Tiger trout have been reported to grow faster than natural species, though this assessment is not universal, and they have been widely stocked for sport fishing.
Tiger trout are known to be highly piscivorous (fish-eating), and are a good control against rough fish populations. This makes tigers popular with many fish stocking programs, such as with the Utah Division of Wildlife Resources. Their own population numbers can be tightly controlled as well, since they are sterile.
Many states have had stocking programs for tiger trout. Wisconsin discontinued its program in the late 1970s. Tigers were exclusively stocked in the Great Lakes. After the stocking program was discontinued, a 20-pound-plus world-record tiger was caught in the Great Lakes.
Wild tiger trout
Wisconsin currently has no stocking program for tigers, but the hybrids show up naturally in the state's small streams. Given that water quality is the best it has been in 20 years, the brook trout population has boomed in recent years. Thus, more wayward male brook trout have been found around brown trout redds, perhaps accounting for the hybrids.
Michigan tends to have a number of tiger trout in its streams, due to its high population of brook trout. Catching them consistently would not be possible.
- Mark A. Nale When a Trout is a Tiger! Pennsylvania Council of Trout Unlimited. Retrieved 11 September 2006
- The Brown Trout Brook Trout hybrid aka Tiger trout - Brown Trout Facts about Spawning, Habitat & Fly Fishing Guide
- Salmo x Salvel hi inus trutta x fontinalis USGS Nonindigenous Aquatic Species database. Retrieved 11 September 2006
- Beautiful Bastards: Check Out These Tiger Trout Photos | Field & Stream
- Thousands of tigers released in Utah (trout that is!) Utah Division of Wildlife Resources, 24 May 2005. Retrieved 11 September 2006
- Watch out, Utah chubs: Tiger trout placed in Scofield Reservoir Utah Division of Wildlife Resources, 24 May 2005. Retrieved 11 September 2006
- Tiger Trout & Hybrids Pennsylvania Fish & Boat Commission. Retrieved 11 September 2006
- Tiger Trout Fishing - Utah Fish Species - Utah Fishing Info