A proprioceptive mechanism for swimming

Aquatic animals exhibit a tremendous diversity in physiology and in shape, consequently, this implies a huge variation of gaits in animals for achieving locomotion. Nevertheless, we expect general mechanisms at play because all the movements result from a drag-thrust balance. While learning to swim, we ascertained that an efficient locomotion is strongly dependent on the synchronisation of the muscle activation with respect to the dynamics of the surrounding fluid.

Sensory feedback should play an important role because motion must be obviously adapted to the environment of the moving organism. This information encompasses the traditional five senses as well as proprioception which is the sense of self-movement or body position.

We aim at addressing the mechanisms providing swimming locomotion driven by proprioception. We suggest that the swimming gaits might be selected by a proprioceptive feedback linking the actual body deformation and the state of the surrounding fluid. By means of a robotic fish we validate our proprioceptive hypothesis to later model the system. We compare our experimental results to our theoretical predictions and we show that the agreement is excellent.