The red lionfish (Pterois volitans) is a venomous coral reef fish in the family Scorpaenidae, order Scorpaeniformes.

The red lionfish was first formally described in 1758 as Gasterosteus volitans by Carl Linnaeus in the 10th edition of his Systema Naturae in which he gave the type locality as Ambon Island in Indonesia.

[7] The specific name volitans means "flying", presumed to be a reference to the large pectotral fins resembling wings.

The embryos secrete an adhesive mucus allowing them to attach to nearby intertidal rocks and corals before hatching.

Lionfish have, however, been found in the stomachs of Nassau and tiger groupers in the Bahamas,[12] but the former is critically endangered and therefore highly unlikely to provide significant predation.

[13] The Bobbit worm, an ambush predator, has been filmed preying upon lionfish in Indonesia;[14] similar species inhabit the Caribbean.

Among their tactics is a "persistent-pursuit strategy" in which they capture fish twice as fast as them in spite of lacking crypsis by exploiting the periodic pauses in swimming of their prey with their uninterrupted slow approach.

When they get within 9 cm, they strike using a "rapid expansion of the rostrum and low pressure within the buccal cavity to draw in prey that are immediately in front of the mouth".

Between outcompeting similar fish and having a varied diet, the lionfish is drastically changing and disrupting the food chains holding the marine ecosystems together.

[disputed – discuss] They are slow swimmers, so when threatened, the fish turns these spines towards its attacker, even if this means swimming upside down.

[25] Adult lionfish specimens are now found along the East Coast from Cape Hatteras, North Carolina, to Florida, and in Bermuda, the Bahamas, and throughout the Caribbean, including the Turks and Caicos, Haiti, Cuba, the Dominican Republic, Guadeloupe, Puerto Rico, St. Croix, Belize, Honduras, Aruba, Cayman Islands, Colombia, Saint Lucia, St. Martin, and Mexico.