Scorpaeniformes

The Scorpaeniformes are a diverse order of ray-finned fish, including the lionfishes and sculpins, but have also been called the Scleroparei. It is one of the five largest orders of bony fishes by number of species, with over 1,320.

They are known as "mail-cheeked" fishes due to their distinguishing characteristic, the suborbital stay: a backwards extension of the third circumorbital bone (part of the lateral head/cheek skeleton, below the eye socket) across the cheek to the preoperculum, to which it is connected in most species.

Scorpaeniform fishes are carnivorous, mostly feeding on crustaceans and on smaller fish. Most species live on the sea bottom in relatively shallow waters, although species are known from deep water, from the midwater, and even from fresh water. They typically have spiny heads, and rounded pectoral and caudal fins. Most species are less than 30 cm (12 in) in length, but the full size range of the order varies from the velvetfishes belonging to the family Aploactinidae, which can be just 2 cm (0.79 in) long as adults, to the skillfish (Erilepis zonifer), which can reach 183 cm (6.00 ft) in total length.