The coho salmon, also know as the silver salmon can be distinguished by the fine dark spots on the back and upper lobe of the tail fin, the long anal fin and gray gums.

Coho feed primarily on alewives, smelt, and other small fish. Adult coho spawn during the fall in riffle areas of streams in redds (nests of gravel) which the females construct. After spawning is completed they die. Normally, coho have a three year life cycle; however, a few males will return to spawn at two years of age and are known as "jacks". Occasionally some coho may live to the age of four; these fish are the 20 pound coho that are caught infrequently in Lake Michigan. The average mature fall coho salmon will weight 5 to 6 pounds before spawning.

Up to 75% of the salmonids caught annually in the Illinois portion of Lake Michigan are coho salmon. Because this species dies after spawning and the recruitment from stream spawning is very limited, an annual stocking program is necessary. In Illinois coho are reared in an accelerated fashion and in 6 months are stocked as 5-6 inch long fish in the spring. Due to the lack of clean, cool streams salmon do not reproduce in Illinois.

Shoreline fishermen are generally successful fishing for this species in the spring, using power lines and pole and line baited with nitecrawlers, small alewives or strips of large alewives and small spoons. Snagging for mature coho is permitted in selected locations during the fall months (snagging is illegal in Wisconsin and many other areas, check your local regulations). Trolling offshore in April, May and June is most productive when using spoons, plugs, spinners and flies and squids preceded by dodgers. Even whole alewife and smelt can be successful when trolled. Coho prefer temperatures in the mid-50s F. and generally are found nearer the surface than chinook. After 60 degrees F. coho tend to go deeper or lakeware in finding their preferred temperature. Coho may be found in water temperatures from 45 to 60 degrees F., with a peak feeding temperature at 54 degrees F.