Brown-gold colouring, fading to whitish on belly. Sides patterned with small dark brown spots. Bright red eyes. The rock bass (Ambloplites rupestris, Ambloplites constellatus), also known as the rock perch, goggle-eye, or red eye is a species of freshwater fish in the sunfish family (Centrarchidae) of order Perciformes. They are similar in appearance to smallmouth bass but are usually quite a bit smaller. The average rock bass is between 6-10 inches, and they are rarely over a pound. Rock bass are native to the St Lawrence River and Great Lakes system, the upper and middle Mississippi River basin in North America from Québec to Saskatchewan in the north down to Missouri and Arkansas, and throughout the eastern U.S. from New York through Kentucky and Tennessee to the northern portions of Alabama and Georgia and Florida in the south. Has reached a maximum recorded length of 43 cm (17 in), and a maximum recorded weight of 1.4 kg (3.0 lb). It can live as long as 10 years. These fish have the ability to rapidly change their color to match their surroundings. It is this chameleon-like trait that allows them to thrive throughout their wide range.
Found throughout NW Ontario to Manitoba border. The rock bass prefers clear, rocky, and vegetated stream pools and lake margins. It is carnivorous, and its diet consists of smaller fish, insects, and crustaceans. Rock bass can be surprisingly unflustered by the presence of human activity, living under lakeside docks and near swimming areas.
A. rupestris is sometimes called the redeye or redeye bass in Canada, but this name refers more properly to Micropterus coosae, a distinct species of Centrarchid native to parts of the American South. Rafinesque originally assigned the rock bass to Bodianus, a genus of marine wrasses (family Labridae).