Native densities, distribution, and diurnal activity of Red Sea lionfishes (Scorpaenidae)

As invasive lionfish populations continue to expand in the Western Atlantic and Caribbean, understanding the ecology and foraging behavior of lionfish in their native habitats will help identify biotic constraints that may improve management of invaded reefs. The most comprehensive survey of lionfish, concluded to date, of native Red Sea lionfish was undertaken to identify potential differences in vertical distribution, density and diurnal cycles of foraging behavior. The overall, combined density of lionfish was estimated at 47.9 fish ha(-1), the highest yet recorded throughout their native range. The most commonly encountered lionfish species were Pterois miles (26.4 fish ha(-1)) and P. radiata (20.8 fish ha(-1)). The density of P. miles was significantly greater at the northernmost site surveyed and also significantly greater at depths less than 15 m, with individuals often observed in aggregations. In contrast, P. radiata were often solitary and evenly distributed along the reef profile. Despite ecological differences between these 2 species, the majority of foraging activities for both P. miles and P. radiata occurred around or after sunset. These results validate that the shallow coral reef habitats of the Red Sea host the highest densities of lionfish in their native range and highlight areas of ecological variability among native lionfish species.