Meeting Abstract
The sensory world of free-swimming animals differs radically from that of substrate-dwelling animals. Those carried with the surrounding water and unable to detect its bulk flow have a harder task of detecting objects causing the flow, such as an attacking predator. Cues from local water deformations are nevertheless available to such animals, and reconstructing possible causes of the signals is a fundamental problem in sensory ecology with potential applications to bio-inspired robotics. We present a theory that clarifies what information is contained in disturbances generated by an attacking predator, and we apply it to planktonic copepods that have mechanosensory hairs deployed in a one-dimensional array along a pair of antennules. The theory reveals the presence of “blind spots”, potential ambiguities in resolving from which of two sides a predator attacks, and whether it generates a bow wave or suction. Our results show that free-swimming animals perceive an intriguingly ambiguous world, yet they may nonetheless extract sufficient information on the location and imminence of the attack to make informed life-saving decisions in their behavioral reactions.
