Burst-and-coast swimming in zebrafish

Swimming kinematics of small fish such as zebrafish are characterized by intermittent sequences consisting in an active swimming phase directly followed by a passive coast phase. These specific sequences are based on a coupling between sensing and decision: fish use the passive time to sense their environment and prepare their next move. Fish essentially use vision and the lateral line system to see and sense their surrounding environment. The mechanisms that govern this “sensing” to “decision-making” (S2D) process are still to be understood and detailed. This work is an attempt to characterize these sequences using several archetypal model experiments and models gathering hydrodynamics, statistics and behavioral sciences. We will focus on new results obtained from real fish experiments in free swimming and forced gait configurations (using a controlled swimming channel). We will show how the statistics of these S2D sequences evolve with the conditions of the experiment; the important parameters being here the external flow conditions and the size of the habitat, but also the species and the maturity state of the fish (larva, juvenile or adult). We believe that these results will have direct implications on the design and implementation of biomimetic robotic systems.