Photo by Jeremy Perkins ©
Physical Characteristics

Tiger trout, a cross between a brown trout and brook trout, has a unique, dark maze-like pattern all over a brownish, gray body. The belly is yellowish orange as are the pectoral, pelvic and anal fins. The tail fin is square.

General Info

The tiger trout is a sterile, intergeneric hybrid of the brown trout and the brook trout. 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. Artificially, tiger trout can be produced reliably enough to be grown by 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.

Many states have stocking programs for tiger trout. Wisconsin discontinued their program in the late 1970s. They 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. Wisconsin has NO stocking program for tigers currently. There are tigers in Wisconsin small streams now. The tiger is happening in nature in Wisconsin. The water quality of the small streams is the best it has been in 20 years. The brook trout population has boomed in recent years. A few more wayward male brook trout have been found on brown trout redds.