Montana Field Guide

Pygmy whitefish are native to clear, cold lakes of northwest Montana. As the name suggests, they seldom exceed 6-8 inches in length. Consequently, they are seldom seen by Montanans but may provide an important forage fish, especially for large lake and bull trout. They eat crustaceans and aquatic insect larvae and live in the same deepwater habitat as lake whitefish, except in the fall when they spawn in shallow lake or stream waters.

Silvery except for olive brown back. Mouth overhung by snout. Has one flap of skin between nostrils on each side, and a membrane surrounding each eye has a distinct notch below pupil (see Mountain Whitefish for illustration).

Migrates a short distance into tributary streams to spawn.

Deep cold-water lakes and their associated tributaries. Spawns in tributary streams.

Feed mainly on zooplankton throughout lives. July-Dec. Flathead Lake study showed these foods to be important; Daphnia Thorata-70%, Epischura-13%, Organic debris-10%, and chironomid larvae-6%.

Forage for predator fish.

Sexually mature as early as 1 year but mostly at 2+ years. Spawns Nov-Jan, probably during night. Eggs hatch in Spring.