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
Fish species of the Neretva basin the Neretva river basin of the Adriatic Sea in Bosnia and Herzegovina. On the basis of all relevant indicators it is necessarily to take urgent measures, continuous and organized action, to dramatically reduce the quantity (if is not possible to exterminate) of this allochthonous type of fish, as well as to attempt to revitalize autochthonal fish populations, with fish stocking of local, especially salmonids species, all in order to prevent the same fatal experience with the water ecosystem in the UK, and prevent, if possible, this type of allochtonous species colonization of the Neretva River basins with irreversible effects. Like