Abstract: Using the juveniles of Spinibarbus sinensis as the experimental model, we examined the effect of simulated predation on the collective motion of fish shoals with different sociability. Twenty groups of both high and low-sociability shoals were formulated. Within each group, there were one focal fish with either high or low-sociability and nine companions with unknown sociability. The duration of stress response, number of dispersals and accelerations of fish shoals were measured before and after simulated predation stimulation. The results showed that the stress response of shoals with high-sociability was significantly shorter than that of low-sociability shoals. The proportion of high-sociability focal fish in the front of the shoals was significantly higher than that of low-sociability focal fish. However, the proportion of the position of the focal fish remained stable before and after the simulated predation stimulation. The number of dispersals decreased and the number of accelerations increased significantly after the simulated predation stimulation. However, the sociability of the focal fish did not affect both variables. Spinibarbus sinensis shoals could adaptively adjust their behavior, with a high cohesion and more confusion effect to deal with the predation risk. Fish shoals with high sociability were more sensitive to predation and had better information communication than those with low sociability.

Key words: Spinibarbus sinensisi, personality, shoaling behavior, predation risk.