http://www.flmnh.ufl.edu/fish/Gallery/Descript/RedLionfish/RLionfish.html
· Predators
Published records of natural predators of adult red lionfish are unknown. But again, studies of the closely related Pterois miles may provide us with some indication of the natural history of P. volitans. In the Gulf of Aqaba, Red Sea, the piscivorous cornetfish, Fistularia commersoni, appears to be a predator of Pterois miles. Judging by the presence of a specimen of P. miles in the stomach of a large F. commersoni, and its particular orientation therein, a published note concludes that cornetfish in the Red Sea may utilize their ambush tactics to seize lionfish safely from the rear, consuming them tail first.
As cornetfishes are widespread, effective piscivores, species sympatric with P. volitans may be predators of the same.
Other as yet undocumented predators of the red lionfish might include sharks, as many sharks are known to consume noxious or venomous organisms with no obvious ill effects.