E-Fauna BC: Electronic Atlas of the Wildlife of British Columbia

Dorsal spines (total): 0; Dorsal soft rays (total): 11 - 15; Anal spines: 0; Anal soft rays: 10 - 13; Vertebrae: 53 - 61. Body slender, elongate, nearly cylindrical in cross section but variable, more compressed laterally than round whitefish. Head short; eye moderate, its diameter less than snout length; snout more or less pointed, compressed laterally, pinched, rounded in lateral view, a single flap of skin present between nostrils. Mouth small, ventral in position, overhung by snout; maxillaries extending posteriorly almost to anterior margin of eye in adults. Teeth small, restricted to a small patch on tongue and on gill rakers in adults, although small teeth may be present on the premaxillaries in young, but absent from jaws, vomer, palatines and pre maxillae in adults. Overall coloration silvery, but light or dark brown or olive on back, becoming silvery in sides and white below. Scales, specially on back, may have pigmented borders. dorsal fin often dusky, pelvic and pectoral fins in adults with amber tint.

The biology of riverine mountain whitefish is reasonably well known. They have a complex life cycle and make major spawning, over-wintering, and summer feeding migrations. In contrast, the biology of lacustrine populations is poorly known. We do know that there are major differences in body form between riverine and lacustrine populations and, that in Kootenay Lake there are spatially and temporally separate spawning runs. This suggests that in large lakes there may be multiple demes. Additionally, in many interior rivers there are two riverine forms — a normal form and a longnose “pinocchio” form. The two forms differ in foraging behaviour, morphology and there is some evidence of genetic differences. This should be checked out.

North America: Mackenzie River drainage in Northwest Territory, Canada south through western Canada and northwestern USA in the Pacific, Hudson Bay and upper Missouri River basins to Truckee River drainage in Nevada and Sevier River drainage in Utah, USA.