The physical principles of swimming and flying in animals are intriguingly different from those of ships and airplanes. The study of animal locomotion therefore holds a special place not only at the frontiers of pure fluid dynamics research, but also in the applied field of biomimetics, which aims to emulate salient aspects of the performance and function of living organisms. For example, fluid dynamic loads are so significant for swimming fish that they are expected to have developed efficient flow control procedures through the evolutionary process of adaptation by natural selection, which...