The tiger trout (Salmo trutta X Salvelinus fontinalis) is a sterile, intergeneric hybri 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.