Chum salmon
Oncorhynchus keta
Similar species
Size
50–70 cm, 2–5 kg.
Appearance
Body deeper than Finnish salmonids in general. In common with other Pacific salmon (Oncorhynchus), the anal fin has 12–20 rays, compared with a maximum of 12 in Finnish salmonids. Prior to spawning the male develops a pronounced kype.
Colouring
Overall silver, back dark with a few indistinct spots. Colour changes to dark olive green at spawning time, when belly also becomes darker and sides acquire purple blotchy streaks, darker towards the tail. In males, underside fins become tipped with white.
Reproduction
Chum salmon enter freshwater in autumn to spawn in the headwaters of rivers. Eggs laid on gravel bottoms, the fish dying after spawning. In Finland, some may spawn in the rivers Tenojoki and Näätämöjoki.
Food
Crustaceans, squid, other fish.
Distribution and habitat
The offspring of chum salmon introduced on the coast of Murmansk by the Russians have been encountered running the rivers Tenojoki and Näätämöjoki. Reproduction has been successful in these waters, but whether the spawning fish are the progeny of these or some other rivers is not known. They may also have been introduced.
