Chinook or King Salmon (Oncorhynchus tshawytscha) are the largest salmon. They may reach around 150 cm in length and can occasionally exceed 23 kg; other salmon rarely exceed 14 kg. These fish have black spots on the back and on the dorsal, adipose and both lobes of the caudal (tail) fin. The gums are dark at the base of the teeth. At sea, these fish are blue, green, or gray above and silver below. Small males are often dull yellow while large males are often blotchy with dull red on the side. Breeding individuals are dark olive-brown to purple. (Page and Burr 1991)
The Chinook is the least abundant of the Pacific Salmon. It is anadromous (moving from the ocean to freshwater to breed), occurring in the Pacific Ocean and coastal streams. It is found in northeast Asia and, in North America, in Arctic and Pacific drainages from Point Hope, Alaska, to the Ventura River in California, occasionally straying south to San Diego, California. This species is widely stocked outside its range, notably in the Great Lakes. (Page and Burr 1991)
In comparison to other Pacific salmon: Sockeye and Chum Salmon (O. nerka and O. keta) have no large black spots; Coho Salmon (O. kisutch) have no black spots on the lower lobe of the caudal fin and have gums that are light at the base of the teeth; and Pink Salmon (O. gorbuscha) have large oval black spots on the back and caudal fin and do not exceed 76 cm in length. (Page and Burr 1991)
Chinook Salmon spawn once and die. For detailed information on the biology and status of this species, including conservation issues, see this resource from the NOAA Fisheries Office of Protected Resources.