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.