Percopsis omiscomaycus


Image of a trout-perch
Joseph R. Tomelleri. Used with permission.
Species of Conservation Concern

Percopsidae (trout-perches)


Small size, silvery color with blackish spots in rows along upper sides. Single dorsal fin, adipose fin present. Body rough to touch. Deeply forked tail fin. Mouth is horizontal and small (the upper jaw does not extend as far back as the front of the eye). Only Missouri fish with both adipose fin and rough-edged scales, characteristics of trout and perch, respectively—thus the common name trout-perch. Most closely related to cavefishes and pirate perch.


Total length: 3 to 5 inches; maximum 5 1/2 inches.

Habitat and conservation

Most commonly found in deep pools of prairie streams that have permanent flow, moderately clear water and bottoms of sand or gravel. Apparently very sensitive to pollution and sedimentation, its decline is likely related to agricultural pesticides and erosion. The extensive channelization, in earlier decades, of northern and western Missouri streams has destroyed the pool-type habitats this species requires.


Most active at night, feeding mostly on aquatic insects and other invertebrates from shallow stream bottoms.

image of Trout-Perch distribution map
Distribution in Missouri

Occurs in Grand and Chariton River systems; formerly eastward along the Missouri and Mississippi to St. Charles and Perry counties. On the verge of disappearing from our state.


Listed as a Species of Conservation Concern, this fish is imperiled in Missouri. It used to be widespread in northern Missouri but most it its populations have been extirpated, and it is not common anywhere in the state.

Life cycle

Spawning probably occurs in early spring (March), near the edges of streams. There is no parental care. At the end of four growing seasons, they reach about 4.5 inches, and females grow larger than males. Most trout-perches live 4 to 5 years.

Human connections

This is one of only two species that survive in the trout-perch family, which has traits of both soft-rayed and spiny-rayed fishes. As one of the surviving remnants of a larger group that is now mostly extinct, they provide priceless clues to understanding the fossil fish of the past.

Ecosystem connections

In northern states where this species is more abundant, it provides food for several game fish. In Missouri, this species is too rare to serve that ecological purpose.