Prosopium
Prosopium is a genus of freshwater whitefishes found in North America and parts of eastern Russia. It contains three fairly widespread species: the round whitefish, the pygmy whitefish, and the mountain whitefish. The remaining species, the Bonneville cisco, the Bonneville whitefish, and the Bear Lake whitefish are endemic to Bear Lake.
Species
There are currently six recognized species in this genus:| Image | Scientific name | Common Name | Distribution |
| Prosopium abyssicola | Bear Lake whitefish | Bear Lake on the Utah-Idaho border | |
| Prosopium coulterii | Pygmy whitefish | mountain streams and lakes in western North America, it also has isolated populations in Lake Superior and in Ekityki Lake, Chukchi Peninsula. | |
| Prosopium cylindraceum | Round whitefish | Alaska to New England, including the Great Lakes | |
| Prosopium gemmifer | Bonneville cisco | Bear Lake along the Utah-Idaho border | |
| Prosopium spilonotus | Bonneville whitefish | Bear Lake on the Utah-Idaho border. | |
| Prosopium williamsoni | Mountain whitefish | Mackenzie River drainage in Northwest Territories, Canada south through western Canada and the northwestern USA in the Pacific, Hudson Bay and upper Missouri River basins to the Truckee River drainage in Nevada and Sevier River drainage in Utah |