Northern Rock Bass

Ambloplites rupestris

Rock_Bass_Goggle_Eye_Ambloplites_rupestris_6-26-13.jpg

Northern rock bass, or goggle-eye, side view photo with black background
Northern rock bass, or goggle-eye, Ambloplites rupestris
Lance Merry
Other Common Name
Goggle-Eye
Family

Centrarchidae (sunfishes) in the order Perciformes (perch-like fishes)

Description

The northern rock bass, or goggle-eye, is thicker-bodied than most other sunfish, with a large mouth and very large eyes. The spiny dorsal fin has 12 spines broadly connected to the soft dorsal fin. The anal fin has 6 spines. The color is variable, but it is generally dark brown to bronze above, often blotched on the sides. There is a distinct pattern of dark spots arranged in parallel lines along the sides; this differentiates the northern rock bass from its closest relatives, the Ozark bass and shadow bass.

Size

Total length: to 11 inches; weight: to 1 pound; maximum about 17 inches and 2 pounds, 12 ounces.

Rock_Bass_Goggle_Eye_Ambloplites_rupestris_Young_10-9-15.jpg

Northern rock bass, or goggle-eye, young individual, side view photo with black background
Rock Bass (Goggle-Eye), Young
Northern rock bass, or goggle-eye, Ambloplites rupestris, young
Habitat and conservation

Streams of the northern Ozarks, tributaries of the middle Mississippi, and a portion of the southwestern Ozarks. Rarely in Ozark reservoirs. Larger individuals are found around boulders, logs, and vegetation beds in deep pools. Most active twilight hours of dawn and dusk, and at night.

Foods

Crayfish and aquatic insects; occasionally terrestrial insects and small fish.

Northern Rock Bass Goggle-Eye distribution map
Distribution in Missouri

Occurs in the northern and southwestern Ozarks.

Status

This game fish was previously recognized as a single species known as “rock bass,” but two very close relatives of the northern rock bass have been recognized in Missouri. Although nearly identical in behavior, habitat, and life histories, the shadow bass (Ambloplites ariommus) and Ozark bass (Ambloplites constellatus) differ from northern rock bass and from each other primarily by where they are found.

Life cycle

Rock bass spawn from the first week in April to as late as early June. Males of this solitary-nesting species build saucer-shaped nests. In Ozark streams, the timing coincides with that of the smallmouth bass. Individuals can live 7 to 9 years.