No evidence for conspecific recruitment for cooperative hunting in lionfish Pterois miles.

Hanaa Sarhan,Redouan Bshary

doi:10.1098/rsos.210828

Abstract

Lionfish are common piscivores in the Indo-Pacific and invasive in the Caribbean. A fin flaring pattern, involving a rapid undulation of the caudal fin and sequential turning of both pectoral fins, was described in zebra lionfish as a signal to initiate cooperative hunting, and it was hypothesized that such hunting tactics may also exist in other lionfish species and contribute to their successful invasion in the Caribbean. Here, we investigated one of those invasive species, Pterois miles, in its natural range in the Red Sea. We did not observe evidence for cooperative hunting in the field. We complemented field observations with a laboratory experiment aimed at inducing subjects to recruit partners for cooperative hunts, exposing subjects to inaccessible prey in transparent housing as well as to a potential partner. We regularly observed the fin flaring pattern, but importantly, it was not directed at the partner. Thus, rather than being a signal, the fin flaring movement pattern seems to be a swimming mode in a confined environment. Furthermore, the two lionfish did not aggregate at the prey housing, reinforcing the field results that this species in the Red Sea does not depend on cooperation to hunt fish.

Highlights

One way in which animals may benefit from grouping is because of the transfer of information regarding the distribution of patchy food [1]
We had asked whether lionfish P. miles in the Red Sea show any evidence for cooperative hunting based on active recruitment, as such hunting techniques might have helped them to become such a highly successful invasive species in the Caribbean
While the fin flaring pattern described in D. zebra was virtually absent in P. miles in the field, it occurred frequently during our laboratory experiments

Summary

Introduction

One way in which animals may benefit from grouping is because of the transfer of information regarding the distribution of patchy food [1]. The transfer of information may be passive, i.e. based on cues, or active due to communication. Active communication warrants shared interest between signaller and receiver. One possible cause is kin selection, like in the waggle dance in honeybees [2] or pioneer ants leaving trails of pheromones that lead foraging ants between food-rich areas and their nests [3]. Recruiting partners yields direct benefits to the signaller. Ravens recruit conspecifics to overcome defence of food by dominant individuals and competitors [4]

Methods

Results

Conclusion