A Pacific salmon (Oncorhynchus keta) with minute specks on its back that is fished for food and sport. or dog salmon Lightly speckled North Pacific fish (Oncorhynchus keta) of the salmon family. The chum salmon ranges from the Mackenzie and Lena rivers in the southern Arctic southward to Japan and the Rogue River. Its weight averages about 10-12 lbs (4.5-5.5 kg). During the autumn spawning season it swims more than 2,000 mi (3,200 km) up the Yukon River