The cannibalism of fish is closely related to stress responses, and aggressive behavior is also affected by the metabolism of serotonin (5-HT) and dopamine. This study was conducted to study the growth, survival, bite marks on the body surface, stress response, and 5-HT and dopamine metabolism in Takifugu rubripes, aiming to explore the effect of moderate feed restriction on cannibalism. Uninjured juvenile Takifugu rubripes (18.61±0.05) g were selected in this experiment. The high amount of feed group (FH) was designed as fish fed four times a day to apparent satiation. The amount of feed was reduced to 85% (FM) and 70% (FL) of the FH group for the treatment groups. Each experimental diet was assigned to triplicate tanks with 30 fish per tank. The feeding trial lasted for 56 days. Bite marks in surviving and dead fish fed the FH diet were observed, while the number was significantly lower compared to that in fish fed the FL and FM diets. The survival rate was significantly lower in the FL and FM groups with moderate feed restriction compared to that in the FH group, but there were no significant differences in final body weight, weight gain, and specific growth rate. Compared with the FH group, the levels of liver glycogen and serum glucose were significantly increased in the FL and FM groups. For the 5-HT pathway, the level of 5-hydroxyindoleacetic acid (5-HIAA) was significantly reduced in the FL group, and relative expression levels of tat1, maob, and htr7 were significantly higher than that in the FM and FH groups. Additionally, relative expression levels of tph1a, tph2, and vmat2 in the FL group were significantly higher than those in the FM group. Compared to the FH group, the expression of tph2 in the FM group was significantly down-regulated, while the expression of ddc was significantly up-regulated. In conclusion, this study revealed that feed restriction was a key factor leading to the cannibalistic behavior of Takifugu rubripes with intact teeth. However, cannibalism was still observed after feeding four times a day to apparent satiation. Moderate feed restriction may exacerbate cannibalism and reduce survival rate by inhibiting the dopamine pathway in the brain. Additionally, Takifugu rubripes may cope with the stress of cannibalism induced by feed restriction via increasing liver glycogen synthesis and gluconeogenesis and enhancing 5-HT metabolism.