Sockeye salmon for courtship. If they waste too much energy, they might not be able to spawn. Males must also make the decision whether to invest energy in fighting for a female or for longevity on the spawning grounds. Aggressive behavior displayed by dominant males is predominantly directed towards intruding dominant males. Sometimes sockeye salmon males behave aggressively towards subordinate males. These encounters are short, with the intruding male leaving after one or two aggressive interactions. Spawning females direct their aggression primarily towards intruding females or other spawning females that are close by. However, they may also direct aggression towards intruding or
Sockeye salmon Resources Commission in an attempt to establish the species as a forage fish for other predator fishes in the lake. This stock has remained and become a favorite target for anglers. In Japan, a landlocked variety termed black kokanee, or ""kunimasu"" in Japanese, was deemed to be extinct after 1940, when a hydroelectric project made its native lake in northern Akita Prefecture more acidic. The species seems to have been saved by transferring eggs to Saiko Lake, 500 kilometers to the south, however. This fish has been treated as a subspecies of sockeye "Oncorhynchus nerka kawamurae", or even an independent