It has been observed since time immemorial that flying and aquatic animals travel in groups in a synchronous pattern which is believed to help them with their movement. In a significant breakthrough in this area, scientists have established how fish save energy by swimming in schools.
The researchers from the Max Planck Institute of Animal Behavior, the University of Konstanz, and Peking University conducted a study in which they used robotic fish to find that schooling fish do coordinate their movement to benefit from the vortices shed by others. It helps them save up to 13.5 per cent of their energy.
The researchers showed that by adjusting their tail beat relative to their neighbours, a strategy called vortex phase matching, the biomimetic fish-like robots could benefit hydrodynamically.
The 3D robotic fish they created has a soft tail fin which swims with an undulating motion very much like a real fish. These artificial fish allow the researchers to measure the power consumption during swimming.
“We developed a biomimetic robot to solve the fundamental problem of finding out how much energy is used in swimming,” said Liang Li, one of the authors of the study.
“If we then have multiple robots interacting, we gain an efficient way to ask how different strategies of swimming together impact the costs of locomotion,” he added.
The researchers ran over 10,000 trials to test their hypothesis and compared the movement of the robotic fish while swimming in pair with when swimming in isolation. The tested every possible position of the fish relative to its leaders and compared the data. The results indicated a clear difference in the amount of energy consumed by the robotic fish when they swam in pair with when they swam alone.
““It is not just about saving energy. By changing the way they synchronise, followers can also use the vortices shed by other fish to generate thrust and help them accelerate,” said co-author Mate Nagy.
The research paper has been published in the Nature Communications journal.