The Scorpaenidae (also known as scorpionfish) are a family of mostly marine fish that includes many of the world's most venomous species. As their name suggests, scorpionfish have a type of "sting" in the form of sharp spines coated with venomous mucus. The family is a large one, with hundreds of members. They are widespread in tropical and temperate seas but mostly found in the Indo-Pacific. They should not be confused with the cabezones, of the genus Scorpaenichthys, which belong to a separate, though related, family, Cottidae.
Scorpaenidae was described as a family in 1826 by the French naturalist Antoine Risso.[1] The family is included in the suborder Scorpaenoidei of the order Scorpaeniformes in the 5th Edition of Fishes of the World[2] but other authorities place it in the Perciformes either in the suborder Scorpaenoidei [3] or the superfamily Scorpaenoidea.[4] The subfamilies of this family are treated as valid families by some authorities.[3]
Scorpaenidae is divided into the following subfamilies and tribes, containing a total of 65 genera with no less than 454 species:[2] [1]
Scorpaenidae have a compressed body with the head typically having ridges and spines. There are 1–2 spines on the operculum, with 2 normally being divergent, and 3–5 on the preoperculum, normally 5. The suborbital stay is normally securely attached to the preoperculum, although in some species it may not be attached. If there are scales 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 1 and 3 spines, normally 3, and 3 to 9 soft rays, typically 5, There is a single spine in the pelvic fin and between 2 and 5 soft rays, again typically 5, 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. In some species, there is no swim bladder. There are venom glands in the spines of the dorsal, anal, and pelvic fins in some species. Most species utilise 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.[2] The largest species is the shortraker rockfish (Sebastes borealis) which attains a maximum total length of while many species have maximum total lengths of .
Scorpaenidae species are mainly found in the Pacific and Indian Oceans, but some species are also found in the Atlantic Ocean.[2] Some species such as the lionfishes in the genus Pterois are invasive non native species in areas such as the Caribbean[5] and the eastern Mediterranean Sea.[6] They are found in marine and brackish habitats. They typically inhabit reefs, but can also be found in estuaries, bays, and lagoons.