Individualistic behavioural traits have long been overlooked, dismissed as either noise or maladaptive deviation to atypical situations. We investigated individual variation in two strains of cloned red-spotted cherry salmon, Oncorhynchus masou macrostomus, in a series of experiments under laboratory conditions. Using principal component analysis, we found that their basic responses such as distance moved, space used and foraging mode grouped along five major dimensions; individuals could be discriminated from each other reliably and showed clear behavioural individuality. Interrelationships between behaviour patterns that differed between the two clonal strains suggested the potential for a genetic basis to behavioural individuality. One or two of the behaviour patterns explained intraclonal variation in individual growth histories. We conclude that behavioural individuality can have an adaptive significance.