Any of several species of showy Indo-Pacific fish of the scorpion-fish family (Scorpaenidae), noted for their venomous fin spines, which can inflict painful, though rarely fatal, puncture wounds. Lionfish have enlarged pectoral fins and elongated dorsal fin spines, and each species bears a particular pattern of bold stripes. When disturbed, the fish spread and display their fins, and, if further pressed, present and attack with the dorsal spines. Pterois volitans, sometimes kept by fish fanciers, is striped with red, brown, and white and grows to about 12 in. (30 cm) long. Several smaller Indo-Pacific species of the genus Dendrochirus are also known as lionfish.