Sockeye salmon subordinate males. Aggressive interactions between females only last one or two charges and/or chases. The intruder retreats and the spawning female settles back in her redd. These acts of aggression are important in terms of reproductive success, because they determine the quality of the nest site the female obtains and access to males. Competition for food or space while the salmon are in their lake residence period can exist. This happens when there is a more populous class of young sockeye or when there are multiple classes present. It can also happen when resources are in short supply. Interspecific competition
Paradise fish less aggressive than the wild type, but also less hardy, having more trouble with low temperatures. Paradise fish The paradise fish, "'paradise-fish"', paradisefish, or paradise gourami ("Macropodus opercularis") is a species of gourami found in most types of fresh water in East Asia, ranging from the Korean Peninsula to northern Vietnam. This species can reach a standard length of , though most are only about . Paradise gouramis were one of the first ornamental fish available to western aquarium keepers, having been imported 1869 to France by the French aquarium fish importer Pierre Carbonnier in Paris. The paradise fish is