No evidence that lionfish Pterois miles coordinate and reciprocate during hunts

Collaborative hunting can be defined as predators coordinating their movements in time and space, assuming different roles in catching prey. As lionfishes are naturally solitary hunters; an experimental study documenting active recruitment, coordination and alternating (potentially reciprocal) striking in dwarf lionfish Dendrochirus zebra received major attention. A hypothesis was that collaborative hunting may contribute to the successful invasion of another lionfish species, Pterois miles, in the Caribbean. A first study on P. miles in the native range, the Red Sea did not find evidence for any recruitment signaling. Here, we expand on these results, testing for coordinated movements and for alternation in strikes. We exposed subject pairs to inaccessible prey in three transparent housings. The two lionfish did not aggregate at the same prey housing or even share larger space units in the presence of prey. In a second experiment, we found that some alternation can be induced if prey i...