A review of chemical communication in freshwater fish

Since communication between individuals of a species of fish by chemical agents (pheromones) was first demonstrated in 1932, such a process has been suggested in many aspects of fish behavidïo'ur and development. This review describes observations on such mechanisms in shoaling behaviour and beneficial conditioning of water, homing of migratory fish, communication of alarm, ‘crowding factor’ (which adversely affects growth, survival and fecundity in dense populations), pair formation and spawning, and a range of other social interactions. Some of the chemicals involved have been isolated and identified, but most are indicated by behavioural observations. Pheromones are of great significance in fish behaviour and ecology, and are likely to be an important factor in culture operations.