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. The gill membranes are not attached to the isthmus. Some species have no
swim bladder. Venom glands are in the spines of the dorsal, anal, and pelvic fins in some species. Most species use internal fertilisation, and some species are
ovoviviparous while others lay their eggs in a gelatinous mass, with
Scorpaena guttata being reported to create a gelatinous "egg balloon" as large as across. ==Distribution and habitat==