Montana Field Guide

The Sauger is one of two native percid species to Montana east of the Continental Divide closely resembling the introduced walleye. It inhabits both large rivers and reservoirs, but is mainly a river fish. In the spring, Sauger broadcast their spawn over riffles in rivers. Sauger are a highly prized sport fish and in some areas outside Montana are also commercially fished. Their major food items are insects and small fish.

For a comprehensive review of the ecology, conservation status, threats, and management of this and other Montana fish species of concern, please see Montana Chapter of the American Fisheries Society Species of Concern Status Reviews.

One of the most important features to differentiate sauger from walleye is the spotted dorsal fin, which has a spiny appearance. Sauger jaws and the roof of the mouth have large canine teeth. The body is almost round in cross section. The anal fin has 2 spines and 11 to 14 (usually 12 or 13) soft rays. The body often has a grayish hue with dark blotches.

Spawning is often accompanied by migration upstream and/or into tributary streams in the spring. Long migration occurs in the Yellowstone and Missouri rivers.

Sauger inhabit the larger turbid rivers and the muddy shallows of lakes and reservoirs. They spawn in gravelly or rocky areas in shallow water and seem to prefer turbid water.

The young eat aquatic insects and crustaceans. Adults feed mainly on fish. The very young feed on zooplankton. Young-of-the-year in the Missouri River are largely piscivorous.

A large, vital spawning and feeding migration has been observed to occur from the lower reaches of the middle Missouri River to an area between Fort Benton and Morony Dam. The Tongue and Powder rivers are vital spawning areas for the Yellowstone River population.

Sauger spawn from mid-April to May at water temperatures of 50 degrees F., with peaks early in May in a middle Missouri River study. They are sexually mature at 3 to 4 years. Eggs are cast over the bottom and incubate in 12 to 18 days at 50 degrees F.

Angler harvest, channelization, water flow fluctuations, migration barriers, loss of spawning and rearing habitat, and environmental degradation have resulted in declines in distribution and abundance of sauger populations rangewide (Rawson and Scholl 1978, Hesse 1994, Pegg et al. 1997). Similar factors have been implicated in the declines observed in Montana. Habitat loss and the presence of migratory barriers (i.e. dams, diversions) are the primary causes of the reduced distribution of sauger in Montana.