The chinook salmon is also known as the king salmon. It is distinguished by dark spotting on the back and usually on both lobes of the tail, a long anal fin and teeth set in black gums. Chinook feed primarily on fish such as alewives and smelt.
Most chinook have a four-year life span.
Mature chinook spawn similarly to coho salmon, then die. A portion of a year class of chinooks may return before the normal four years to spawn. A summary of this behavior and their size at sexual maturity follows. Some chinook may live longer than 4 years and reach 40 pounds or more. The chinook run usually peaks before the coho run.