Wyoming Fish Species: Rock Bass

Rock bass are native throughout the Mississippi River and east along the Atlantic seaboard.  They also extend into the St Lawrence River and Great Lakes system and North America from Québec to Saskatchewan in the north. They prefer clear, rocky, and vegetated stream pools and lake margins. Rock bass can be surprisingly unflustered by the presence of human activity, living under lakeside docks and near swimming areas.
 
Compared to most sunfish and crappie, rock bass are stout and stocky.  They have red eyes and brassy flanks with black spots. The mouth is large, and the upper jaw extends to below the middle of the eye. The back and sides tend to olive to light brown with horizontal rows of black spots. These smallish fish seldom exceed 10 inches in length. These fish have can rapidly change their color to match their surroundings. Rock bass live as long as 10 years.
 
Rock bass spawn in the spring, when water temperatures near 70 degrees Fahrenheit. Male bass nest on gravel substrate in a slight current often next to protective cover. Up to 10,000 eggs may be laid per female and more than one female may use the same nest. Males guard and fan the eggs until they hatch. These carnivorous fish feed on small fish, insects, crayfish and other invertebrates.