The cannibalism is a predation defined as the act to kill and to consume an individual of the same species. The intra-cohort cannibalism is the most common in larviculture, and in pikeperch (Sander lucioperca), cannibalism during larva and juvenile development is an important bottleneck and could represent until 95% of death. To our knowledge, behavioural individual differences that exist between cannibals and non-cannibals have never been investigated. In this study, behavioural differences between 25 cannibals and 42 non-cannibals has been analysed with tests (exploration and sociability) to determine their personality. The analyses of personality showed consistent differences between the individuals of the two groups. To conclude, in this species, cannibalism could be explained by consistent behavioural differences, which exist between fish of the same cohort. This result has been completed by the morphological profile and a histological analysis of the individuals of the two groups.