The coho salmon (Oncorhynchus kisutch; Karuk: achvuun) is a species of anadromous fish in the salmon family and one of the five Pacific salmon species. Coho salmon are also known as silver salmon or “silvers”. The scientific species name is based on the Russian common name kizhuch (кижуч).
During their ocean phase, coho salmon have silver sides and dark-blue backs. During their spawning phase, their jaws and teeth become hooked. After entering freshwater, they develop bright-red sides, bluish-green heads and backs, dark bellies and dark spots on their backs. Sexually mature fish develop a pink or rose shading along the belly, and the males sometimes exhibit a slight arching of the back. Mature adults have a pronounced red skin color with darker backs and average 28 inches (71 cm) and 7 to 11 pounds (3.2 to 5.0 kg), occasionally reaching up to 36 pounds (16 kg). The males generally develop a large kype during spawning.
The traditional range of the coho salmon runs along both sides of the North Pacific Ocean, from Hokkaidō, Japan and eastern Russia, around the Bering Sea to mainland Alaska, and south to Monterey Bay, California. Coho salmon have also been introduced in all the Great Lakes, as well as many landlocked reservoirs throughout the United States.
Once Coho Salmon enter freshwater, although they stop feeding, their aggressive nature makes them a great gamefish species as they actively chase down and eat flies and they tend to school in slack water or on current seams, making them easily accessible to anglers. Many fly fisherman enjoy targeting Coho’s over other species as they are much more accessible and make long, acrobatic runs once hooked.
