Lionfish ( <i>Pterois miles</i> ) blow directed jets of water to manipulate prey behavior

Abstract Predation is pervasive in the natural world and shapes evolution of predators and prey. Numerous behavioral adaptations allow predators to manipulate prey behavior, resulting in higher success in predator-prey interactions. The lionfishes Pterois miles and Pterois volitans are highly effective predators and their invasiveness is attributed to their high hunting success. How lionfish attain such a high predation effectiveness remains enigmatic. Lionfish are stalking predators and show a peculiar behavior while approaching their prey fishes: they actively blow directed jets of water at them. This is the only known example of a predator blowing jets of water at mobile prey underwater. The causes and consequences of jet-blowing remain unknown. Here, we tested the hypothesis that lionfish use jets of water to re-orientate their prey and facilitate head-first capture. We conducted two separate experiments with two different groups of lionfish and prey species. We show that lionfish catch more prey head-first when blowing and that prey exposed to jets orientate towards an approaching lionfish, with smaller lionfish being more likely to blow. However, blowing was not determined by the initial orientation of prey and was largely driven by lionfish size. In addition, in one of the experiments, blowing lionfish struck from a further distance, possibly due to prey swimming towards them in response to blowing. Our results show that jet-blowing allows lionfish to manipulate the behavior of their prey by re-orientating them to facilitate swallowing, providing the first evidence that jet-blowing can be used to manipulate the behavior of mobile prey.