Hybrid (Brown Trout X Brook Trout
Also known as:
Tiger Trout - (source: Wikipedia) The tiger trout (Salmo trutta × 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, which evoke the stripes of a tiger. The fish is an anomaly in the wild, with the brook trout having 84 chromosomes and the brown trout 80. 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, causing the creation of an extra set of chromosomes and increasing survival rates from 5% to 85%. 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.
What is a Tiger Trout? [And How to Fish for Them] by Flylords Magazine
(Siberian?) Tiger Trout by Fishwest