Energy Storage by Elastic Mechanisms in the Tail of Large Swimmers—a Re-evaluation

Fish and cetaceans may use, like mammals, elastic mechanisms to reduce metabolic cost of locomotion. Such energy savings require a detailed tuning of material properties and the dynamics of the system. Bennett et al. (1987, J. Zool., Lond.211, 177-192) investigated the possibility of energy storage for cetaceans. They concluded that for steady swimming at cruising speed the compliance of the tissues would increase metabolic cost. We re-evaluated this question by expanding the model using a more realistic representation of the hydrodynamic forces. We found that the elastic tissues in the body of cetaceans significantly reduce the cost of locomotion.