Coho Salmon


World Record: 33lbs 4oz
Salmon River, New York
September 27th 1989
Length: approx. 28 inches
Found in: Rivers & Ocean
Cold Waters 12C


The coho salmon’s body is fusiform, streamlined, somewhat laterally compressed; the snout becomes extended, narrow, and turned down at the tip in breeding males; the mouth is greatly deformed in breeding males, with the lower jaw enlarged and turned up at the tip so that the mouth is unable to close; the body colour of marine or Great Lakes adults is steel blue to slightly green on the back, brilliant silver on the sides, white on the underside, and small black spots on the back and sides above the lateral line and upper lobe of the caudal fin; breeding males become darker on the head and back, the sides are dull with a brilliant red stripe, and the underside is grey to black; the colour of females changes little and colour changes in Great Lakes males are less spectacular.


The coho salmon spends about 18 months in the lake and returns to streams to spawn in the fall, usually at age 3 or 4 years. Adults move upstream during the day and usually do not travelmore than 240 km (150 miles) in larger rivers. Spawning takes place in swifter water of shallow, gravelly areas of river tributaries from The female prepares the nest in medium to small gravel by lying on her side and beating vigorously with her tail. The eggs fall into spaces between the gravel and immediately the female begins digging at the upstream edge of the nest covering the eggs with the displaced gravel. The female guards the nest as long as she can, but the adults die shortly after spawning. Some fry migrate almost immediately to the sea or lake but most remain at least 1 year in freshwater or lake tributaries. Usually in March or April of the year following their emergence, the young coho salmon (smolts) begin to migrate to the lake.


The food of the marine adult coho is more varied than that of many pacific salmon and consists mostly of fish and invertebrates. In the Great Lakes, the bulk of the food of larger coho consists of rainbow smelt and alewifes.