Sockeye salmon are one of the smaller species of Pacific salmon, measuring 18 to 31inches in length and weighing 4-15 pounds. Sea-going sockeye salmon have iridescent silver flanks, a white belly, and a metallic green-blue top, giving them their "blueback" name. Some fine black speckling may occur on the back, but large spots are absent. Sockeye salmon are prized for their firm, bright-orange flesh.
As sockeye salmon return upriver to their spawning grounds, their bodies turn brilliant red and their heads take on a greenish color, hence their other common name, “red” salmon. Breeding-age males develop a humped back and hooked jaws filled with tiny, visible teeth. Juveniles, while in fresh water, have dark, oval parr marks on their sides. These parr marks are short-less than the diameter of the eye-and rarely extend below the lateral line.