By living and moving in groups, fish can gain many benefits, such as heightened predator detection, greater hunting efficiency, more accurate environmental sensing, and energy saving. Although the benefits of hydrodynamic interactions in schooling fish have drawn growing interest in fields such as biology, physics, and engineering, and multiple hypotheses for how such benefits may arise have been proposed, it is still largely unknown which mechanisms fish employ to obtain hydrodynamic benefits, such as increased thrust or improved movement efficiency. One main bottleneck has been the difficulty in collecting detailed sensory information, corresponding locomotory responses, and hydrodynamic information from real schooling fish.
