Pterois is a genus of venomous marine fish, commonly known as lionfish, native to the Indo-Pacific. Also called firefish, turkeyfish, tastyfish, or butterfly-cod, it is characterized by conspicuous warning coloration with red, white, creamy, or black bands, showy pectoral fins, and venomous, spiky fin rays.[3][4] Pterois radiata, Pterois volitans, and Pterois miles are the most commonly studied species in the genus. Pterois species are popular aquarium fish.[3] P. volitans and P. miles are recent and significant invasive species in the west Atlantic, Caribbean Sea and Mediterranean Sea.[5][6][7]
Pterois was described as a genus in 1817 by German naturalist, botanist, biologist, and ornithologist Lorenz Oken. In 1856 the French naturalist Eugène Anselme Sébastien Léon Desmarest designated Scorpaena volitans, which had been named by Bloch in 1787 and which was the same as Linnaeus's 1758 Gasterosteus volitans, as the type species of the genus.[1][8][2] This genus is classified within the tribe Pteroini of the subfamily Scorpaeninae within the family Scorpaenidae.[9] The genus name Pterois is based on Georges Cuvier's 1816 French name, “Les Pterois”, meaning "fins" which is an allusion to the high dorsal and long pectoral fins.[10]
Molecular studies, and some morphological data too, have indicated that P. lunulata and P. russelli are the same species, P. russelli, and that P. volitans may be a hybrid between P. miles and P. russelli sensu lato.[13]
Pterois are harmful to humans.[14][15] Juvenile lionfish have a unique tentacle located above their eye sockets that varies in phenotype between species.[16] The evolution of this tentacle is suggested to serve to continually attract new prey; studies also suggest it plays a role in sexual selection.[16]
Pterois species can live from 5 to 15 years and have complex courtship and mating behaviors.[17] Females release two mucus-filled egg clusters frequently, which can contain as many as 15,000 eggs.[17][18] Studies on Pterois reproductive habits have increased significantly in the past decade.[18] All the species are aposematic; they have conspicuous coloration with boldly contrasting stripes and wide fans of projecting spines, advertising their ability to defend themselves.[19]
According to a study that involved the dissection of over 1,400 lionfish stomachs from Bahamian to North Carolinian waters, Pterois fish prey mostly on small fish, invertebrates, and mollusks in large amounts, with some specimens' stomachs containing up to six different species of prey.[20] The amount of prey in lionfish stomachs over the course of a day suggests lionfish feed most actively from 7:00–11:00 am, and decrease feeding throughout the afternoon. Lionfish are skilled hunters, using specialized bilateral swim bladder muscles to provide precise control of location in the water column, allowing the fish to alter its center of gravity to better attack prey.[20] The lionfish then spreads its large pectoral fins and swallows its prey in a single motion.[17] They blow jets of water while approaching prey, apparently to disorient them.[21] In addition to confusing prey, these jets of water also alter the orientation of the prey so that the smaller fish is facing the lionfish. This results in a higher degree of predatory efficiency as head-first capture is easier for the lionfish.[22]