Behavioural traits and feeding ecology of Mediterranean lionfish and naivete of native species to lionfish predation

The detrimental effects of invasion by Indo-Pacific lionfish Pterois volitans/miles on western Atlantic fishes have spurred concerns for Mediterranean fish biodiversity, where Lessepsian lionfish P. miles have recently established populations in the eastern basin. In order to assess the potential impact on biodiversity, we examined key behavioural and ecological traits of lionfish and the resident fish community in the Mediterranean that may contribute to lionfish invasion success. We focussed on Cyprus, where lionfish were first sighted in 2012 and have now formed abundant and stable populations. Using field observations, we examined lionfish predatory behaviour and feeding ecology, and naivete of resident fish species to hunting lionfish. Our findings suggest that lionfish in the Mediterranean are crepuscular generalist predators, with targeted prey dominated by small-bodied benthic or bentho-pelagic associated species. Such prey are more likely to be native than introduced (Lessepsian) fishes, with native prey fishes showing greater naivete towards lionfish than Lessepsian prey species. Notably, one of the Mediterranean's key ecological fish species (the native damselfish Chromis chromis) showed the highest level of naivete and was the most heavily targeted prey. Overall, lionfish in the Mediterranean show similar predatory behaviour and ecology to their western Atlantic counterparts. Although the establishment of Mediterranean lionfish populations is still recent, it may result in a similar disruption to reef fish biomass to that recorded in the Atlantic, with impacts on the structure and biodiversity of reef fish communities and the services they provide.