Abstract.- Oncorhynchus nerka , sockeye salmon, spawn in many rivers and lakes of the Pacific Northwest.
Sockeye have complex life histories that span thousands of kilometers.
Sockeye are also a very important resource harvested commercially by many countries including the United States. O. nerka can be easily distinguished from chinook, coho, and pink salmon, by the lack of black spots that are usually dorsally placed. O. nerka can be distinguished from chum salmon by the number and shape of the gill rakers on the first gill arch. Breeding males become laterally compressed and develop a humped back and elongated hooked jaws filled with sharp teeth during returning migration. Some black speckling may occur on the back.