The coho or 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. Most local DNR agencies include a simple guide to identifying the various salmons. Spawning males in fresh water may be bright red on their sides, bright green on their backs and heads, and may have darker colouration on their bellies, as well as hooked jaws (kypes) with sharp teeth. Coho salmon originate in streams around the Northern Pacific, all the way from California and the Sea of Japan north to the Bering Straits. They are fast, active fish, a favourite of the saltwater salmon angler. They were introduced into Lake Michigan in 1966 and are still stocked in huge numbers. Populations in Lake Superior are self-sustaining, and these exotics now reproduce in the Bois Brule.