Dog salmon, Keta salmon, Silverbrite salmon
The chum salmon (Oncorhynchus keta), also known as dog salmon or keta salmon, is a species of anadromous salmonid fish from the genus Oncorhynchus (Pacific salmon) native to the coastal rivers of the North Pacific and the Beringian Arctic, and is often marketed under the trade name silverbrite salmon in North America. The English name "chum salmon" comes from the Chinook Jargon term tzum, meaning "spotted" or "marked"; while keta in the scientific name comes from Russian, which in turn comes from the Evenki language of Eastern Siberia. The term 'Dog Salmon' is most commonly used in Alaska and refers to the Salmon whose flesh Alaskans use to feed their dogs.
In Japan, chum salmon is also known as the white salmon (白鮭 シロサケ, shiro sake), autumn salmon (秋鮭 アキサケ, aki sake) or simply "the salmon" (鮭 サケ, sa ke), while historically it was known in kun'yomi as "stone katsura fish" (石桂魚 さけ, sa ke) up until the Meiji period. In Greater China, it is known academically as the "hook-snout salmon" (Chinese: 钩吻鲑), but is more often called the damaha fish (simplified Chinese: 大马哈鱼; traditional Chinese: 大麻哈魚), which is borrowed from dawa ịmaχa, the Nanai name of the fish used by the Hezhe minority in northern Northeast China.
The body of the chum salmon is deeper than most salmonid species. In common with other species found in the Pacific, the anal fin has 12 to 20 rays, compared with a maximum of 12 in European species. Chum have an ocean coloration of silvery blue green with some indistinct spotting in a darker shade, and a rather paler belly. When they move into fresh water the color changes to dark olive green and the belly color deepens. When adults are near spawning, they have purple blotchy streaks near the caudal peduncle, darker towards the tail. Spawning males typically grow an elongated snout or kype, their lower fins become tipped with white and they have enlarged teeth. Some researchers speculate these characteristics are used to compete for mates.
Chum salmon have the largest natural range of any Pacific salmon. Chum are found all around the North Pacific, off the coasts of Japan, Korea, the Russian Far East, British Columbia in Canada, and from Alaska to California in the United States. They undergo the longest migrations within the genus Oncorhynchus, far up the Yukon River in Alaska and Canada, and deep into the Amur River basin in Northeast China and Russia. In lesser numbers they migrate thousands of kilometers up the Mackenzie River. In the Arctic Ocean they are found in limited numbers from the Laptev Sea to the Beaufort Sea. In North America chum salmon spawn from the Mackenzie River in the Arctic to as far south as the Umpqua River, Oregon, although they were also reported in the San Lorenzo River near Santa Cruz, California in 1915 and the Sacramento River in northern California in the 1950s. In fall 2017 a half dozen chum salmon were counted in Lagunitas Creek about 25 miles (40 km) north of San Francisco, California.
In the open ocean, chum salmon stay fairly high on the water column, rarely diving below 50 m (160 ft). Their typical swimming depths are 13 m (43 ft) from the surface during the day, and 5 m (16 ft) during the night.
Juvenile chum eat zooplankton and insects. Recent studies show that they also eat comb jellies. As adults, they eat smaller fish.
Chum live for an average of three to five years, and chum in Alaska mature at the age of five years.
Two populations of chum salmon have been listed under the Endangered Species Act as threatened species. These are the Hood Canal Summer Run population and the Lower Columbia River population.
