Meeting Abstract
Suction feeding can rapidly capture prey, but it is only effective over a limited spatial range for a brief duration. These constraints present opportunities for a prey fish to evade capture. We have examined the components of successful prey strategy by studying how larval zebrafish (Danio rerio) sense fish predators and coordinate evasive maneuvers. When placed in a small arena, these prey successfully evaded 70% of predatory strikes with a ‘fast start’ escape response and a majority of these evasions were initiated before the predator opened its mouth. To determine the sensory cues that direct an escape response, we built a robotic predator that moved toward prey at a fixed speed. We found that prey responded to this stimulus at distances of greater than 10 body lengths. However, these responses reduced to within 2 body lengths for experiments conducted in the dark, and ceased entirely when we chemically-ablated the lateral line system. By modeling the visual and lateral line stimuli generated by the predator, we found that both sensory systems failed to direct escape responses in an optimal direction, as predicted by game theory models. Instead, responses were consistent with feed-forward control directed on the side of the body away from the stimulus source. Therefore, the limitations inherent to the sensory and motor systems of a fish prey may constrain prey responses to a sub-optimal, but effective, strategy.
