Scorpionfish

The Scorpaenidae have a compressed body with the head typically having ridges and spines. One or two spines are on the operculum, with two normally being divergent, and three to five on the preoperculum, normally five. The suborbital stay is normally securely attached to the preoperculum, although in some species it may not be attached. If scales are present, they are typically ctenoid. They normally have a single dorsal fin, which is frequently incised. The dorsal fin contains between 11 and 17 spines and 8 and 17 soft rays, while the anal fin usually has between one and three spines, normally three, and three to nine soft rays, typically five, A single spine is in the pelvic fin with between two and five soft rays, again typically five, while the large pectoral fin contains 11–25 soft rays and sometimes has a few of the lower rays free of its membrane.

Scorpaenidae species are mainly found in the Pacific and Indian Oceans, but some species are also found in the Atlantic Ocean. Some species, such as the lionfishes in the genus Pterois, are invasive non-native species in areas such as the Caribbean and the eastern Mediterranean Sea. They are found in marine and brackish-water habitats. They typically inhabit reefs, but can also be found in estuaries, bays and lagoons.