Meeting Abstract
The ability to move is one the key evolutionary events that led to the complexity of vertebrate life. The most speciose group of extant vertebrates, fishes, has been documented to display a remarkable diversity of movement patterns during steady swimming. Much less attention has been paid to forward acceleration, despite its potentially larger role in prey capture and predator evasion. We discovered that for the 51 species we studied, this behavioral diversity collapses into one locomotor strategy when fishes are challenged to accelerate, regardless of their body size, shape or ecology. Employing flow visualization and biomimetic models, we provide evidence that accelerating fishes increase their propulsive efficiency by altering vortex ring geometry. Our study demonstrates a fundamental difference between steady swimming and acceleration and suggests a unifying hydrodynamic principle based on a symmetrical wake morphology that is likely conserved across all aquatic undulatory vertebrates.
