Montana Field Guide

The redside shiner is native to Montana west of the Divide and has been introduced into our eastern drainage, probably by bait fishermen. It likely was given its common name because red develops on its sides during the breeding season. The preferred habitat of this fish is cold, clear ponds, lakes and the slow water of streams. It can often be found in schools. The largest redside shiners are about 7 inches long. Populations of these fish can reach nuisance proportions in the lakes of western Montana.

Dark olive to brown on back; dark midside band from snout to tail fin with a narrow light stripe above it; lower sides silver with a reddish wash; underside silvery. Breeding fish highly colored; male has brilliant red and yellow on sides and belly, female is less striking. Body moderately deep and flat sided, front of dorsal fin well behind front of pelvic fins.

Lakes, ponds, and larger rivers where current is weak or lacking (Brown 1971).

Young feed mainly on plankton and adults eat mostly aquatic insects and snails (Brown 1971).

Important forage fish for salmonids. Redside small shiner x peamouth and Redside small shiner x Northern pikeminnow hybrids have both been found in Montana.

Sexually mature in 2-3 yrs. Usually spawns June-July but may spawn as early as may and as late as August. Spawns in schools (Brown 1971).