Genetic Investigation of Snake River and Yellowstone Cutthroat Trout

The relationship between Yellowstone cutthroat trout, Oncorhynchus clarki bouvieri, and Snake River finespotted cutthroat trout, 0. clarki behnkei, was examined with two mitochondrial DNA fragments, COl and ND5. No variation was found within either subspecies, and just one (out of 1069) nucleotide differed between subspecies. Thus, these subspecies are very closely related. Samples for this study were obtained from hatcheries, and may not be representative of the subspecies. 0. c. bouveri were sampled from the Clark Fork Hatchery, in Powell, WY, and 0. c. behnkei were sampled from the National Fish Hatchery in Jackson, WY. Further sampling, preferably from natural populations, is needed to more thoroughly survey the variation within subspecies, and to measure the differences between subspecies.