Kokanee salmon (Oncorhynchus)
The kokanee salmon is the land-locked version of the sockeye salmon and shares many of its characteristics, including a swift swimming style. Like the sockeye, the kokanee salmon is a slender fish with a blue-green back and top of the head, iridescent silver on the sides and white or silver on the belly. Juveniles develop some dark speckling on the back and oval parr marks on the sides.
Kokanee salmon are the product of evolutionary changes in sockeye salmon that were prevented from migrating to the ocean, and thus adapted to surviving exclusively in freshwater lakes. These land-locked fish were faced with a more limited diet than the ocean-living sockeye, which has resulted in the smaller size of the kokanee.
Kokanee feed primarily on plankton, but also eat insects, bottom organisms and larval fish.
Kokanee salmon are native to the freshwater lakes and rivers of the regions surrounding the Pacific Ocean stretching from Japan to Russia and Oregon to Alaska. In North America, kokanee are found in Washington, Oregon, Idaho, and British Columbia. The fish has been introduced to freshwater lakes in New Mexico, California and other western states as well as eastern states such as New York and Maine.
The kokanee is not an anadromous salmon, thus inhabits only freshwater lakes and tributaries. The fish prefers cool, well-oxygenated water with temperatures of 50 to 59 F. Kokanee are generally found near the surface of the water as long as the temperature remains in their preferred range or cooler. As the surface water warms, kokanee may choose deeper water.
The Latin name of the kokanee was formerly Oncorhynchus nerka kennerlyi because the sockeye and kokanee salmon were thought to be distinct species. They are now considered one single species despite their different habitats.