Influence of Environmental Factors and the Condition of Fish on Schooling Behavior

Despite being innate, schooling behavior is subject to the influence of external factors that change the condition of fish or the conditions of their environment and reception. Of the abiotic factors, the strongest influence is exerted by the illumination and the water turbidity, the abundance of visual landmarks, and the flow velocity. The effect of temperature and the gas composition of water (oxygen content) is much less pronounced; only the first information is available about the effect of water salinity. Among biotic factors, schooling behavior is significantly influenced by various social conditions (fish stocking density, social deprivation), feeding and defensive motivations of fish (fish gut fullness, presence of predators), and parasite infestation. The ability of fish to exhibit schooling behavior is reduced in the presence of virtually all pollutants studied.