Montana Field Guide

The predaceous Northern Pikeminnow is native to Montana west of the Continental Divide. It is somewhat pike-like in appearance with its large mouth and elongated body. Northern Pikeminnow prefer lakes and slow-moving waters. They are considered to be highly undesirable in some situations because they feed on young sport fish. They are effective predators despite their lack of teeth. Northern Pikeminnow are among the largest native North American minnows. Weights of over 7 pounds have been reported in Montana, with weights of nearly 30 pounds reported from Canada. Northern Pikeminnow are readily caught on bait, fly, or lure and put up a good fight but are poor table fare. (FWP) Generally 21-30 cm SL(length); may reach length of 63 cm and mass of 13 kg.

Back dark greenish, silvery below. Young have prominent dark spot at base of tail fin. No barbels.

Some Northern Pikeminnow migrate from lakes into tributary streams to spawn.

Prefers lakes and slow - flowing streams of moderate size. Young usually school in shallow water near lake shores and in quiet backwaters of streams (Weisel 1957, Brown 1971).

Most kinds of aquatic invertebrates. Adults frequently eat small fish. Considered a serious predator on young salmon and trout (Brown 1971, Gould personal communication).

Has increased dramatically in Lake Koocanusa after Libby dam was built, but they may be decreasing in the river below the dam due to low spring water temperatures causing delayed spawing (May and Huston 1979, Huston et al. 1984).

Sexually mature 5-6 yrs. Spawns May-early July over gravelly areas in streams or lakes. No patental care (Brown 1971, Weisel 1957). Spawned late May-early June at 55-65 degrees F. in Blackfoot River study (Hill 1958).