Scorpionfish are ray-finned bony marine fish belonging to the family Scorpaenidae. Most of the 450 species of scorpionfish live in tropical and temperate waters from California to Hawaii and especially in the Indo-Pacific. Some scorpionfish, often called lion-fish, live in the Caribbean. Major anatomical characteristics of scorpionfish include a bony structure extending from the eye to the operculum or gill cover as well as a dorsal fin with 11 to 17 long spines and pectoral rays with 11 to 25 spines. The common name of scorpionfish refers to both to the spines and venom of the members of this family, many of which are colored red.
The plumed scorpionfish, Scorpaena grandicornis, of the Atlantic derives its name from the spines and fleshy outgrowths around its head that superficially resemble the shaggy mane of a lion. The first dorsal fin bears a series of heavy sharp spines of which the most anterior ones are hollow and contain poison glands at their base.
The plumed scorpionfish is relatively small, ranging from 6-12 in (15-30.5 cm) and is found in the subtropical seas from Florida to the Caribbean.
The western representative of this group is the California scorpionfish, S. guttata, which is found off the coast of California. They can reach 1.5 ft (0.5 m) in length, and are a red color dorsally, grading gradually to pink below. California scorpionfish are a favorite of sport fishermen but dangerous to catch because of 12 pointed spines on the dorsal fin.
The deadliest species of scorpionfish are found in the Indo-Pacific region. The stonefish (genus Syanceja ) may lurk on coral reefs or on rocky bottoms in shallow water. Venom injected from the hollow spine (like a hypodermic needle) may result in extreme pain which may persist for a long time, frequently resulting in death.