“Lionfish use their broad fins to herd prey into tight spaces before striking.”
Red lionfish are slow-moving Indo-Pacific reef predators armed with long venomous spines. They corner small fish and crustaceans with spread fins before striking, and introduced populations now exert heavy pressure on reef communities in the western Atlantic.
By An Nguyen · Published · Updated
Pterois volitans Scorpaeniformes Scorpaenidae
Measured against the 176 species profiled on this site. Each figure is converted to one unit system from the published range on the page, so the ranks are computed, not quoted.
| Measure | This species | Rank here | Exceeds |
|---|---|---|---|
| Body mass | 1.4 kg | #133 of 176#7 of 13 Actinopterygii | 25% |
| Body length | 38.1 cm | #141 of 176#6 of 13 Actinopterygii | 19% |
| Lifespan in the wild | 15 yr | #98 of 169#5 of 13 Actinopterygii | 40% |
Closest in body mass
Ranks use the upper end of each published adult range, so they compare typical large adults rather than records, and metrics with no published number are left out rather than estimated. The full table is downloadable from the species dataset, and any two species can be put side by side in the comparison tool.
Browse photographs of lionfish across habitat, behavior, anatomy, and life stages.
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Core article
A closer look at habitat, diet, behavior, reproduction, and conservation.
The red lionfish (Pterois volitans) has red, white, and maroon bands, feather-like pectoral fins, and venomous spines. It is an ambush predator native to the tropical Indo-Pacific and an introduced species in the western Atlantic, Gulf of Mexico, and Caribbean, where it preys on juvenile reef fish and faces few native predators.
An adult measures 10 to 15 inches and weighs 1 to 3 pounds, sometimes more in invaded waters. It has 18 venomous spines — 13 dorsal, 2 pelvic, and 3 anal — each sheathed in glandular tissue that delivers a neuromuscular toxin through grooves in the spine when pressure depresses the sheath. High-contrast stripes disrupt its outline against corals and sea fans. Enlarged, webless pectoral fins spread to herd prey, and kinetic jaws open in milliseconds, drawing water and prey into an expandable stomach. It belongs to the scorpionfish family Scorpaenidae, kin to the stonefish.
The lionfish's native range spans the Indo-Pacific from Western Australia and Malaysia to French Polynesia and north to southern Japan, where it hovers under overhangs and in coral crevices on reefs, in lagoons, on rocky slopes, and in mangrove estuaries, from the shallows to about 300 feet. Its modern distribution, though, is an ecological anomaly: after being introduced to the U.S. Atlantic coast — probably through the aquarium trade in the 1980s — it has spread explosively from Rhode Island to Brazil, across the entire Caribbean and Gulf of Mexico, helped by broad thermal tolerance and an ability to thrive on pristine and degraded reefs alike.
The lionfish is a carnivore of small fish, shrimp, and crabs, hunting mostly at dawn, dusk, and night. It flares its pectoral fins to corner small fish against the reef, then may shoot streams of water at prey before lunging with suction. Stomach studies from invaded reefs have recorded individual lionfish eating dozens of juvenile wrasses, gobies, snappers, and groupers in one bout, and the stomach can expand substantially after feeding.
Red lionfish are generally solitary, spending daylight resting under overhangs and showing strong site fidelity — often returning to the same coral head day after day. Facing a threat, an agitated lionfish drops its head and points its dorsal spines forward in a defensive phalanx to present as many venomous tips as possible. Small aggregations can form where prey is dense or during breeding, but males are territorial, meeting rivals with lateral fin-flaring, head-butting, and biting; despite a slow cruising speed, they maneuver precisely, hovering in place or pivoting a full circle on their fins.
Prolific reproduction is the engine of the lionfish invasion. It is a broadcast spawner: at dusk the male circles the female and guides her upward, and in a synchronized ascent she releases two buoyant egg masses of up to 15,000 eggs each, which he fertilizes in the water. In warm water a female can spawn every 3 to 4 days year-round — upward of two million eggs a year — and the gelatinous egg masses carry a chemical deterrent that keeps most predators off. The eggs hatch within 24 to 48 hours into larvae that drift on ocean currents for 20 to 35 days, seeding distant reefs, then settle, develop their stripes and spines, and mature within a year. Lionfish may live 10 to 15 years.
In its native Indo-Pacific the red lionfish is Least Concern, kept in check by large groupers, moray eels, and some sharks. In the Atlantic and Caribbean it is the opposite — one of the gravest threats to marine biodiversity, because native fish have no evolutionary history with it and don't recognize it as danger until too late. Unchecked, lionfish have driven steep declines in native reef-fish recruitment, including commercially important snapper and grouper and ecologically vital parrotfish; lose the parrotfish that graze algae and a reef can flip from coral- to algae-dominated. Control now rests on people: culling programs, organized "lionfish derbies," and promoting lionfish as food — the flesh is white and flaky, and harmless once the spines are removed.
Kingdom
Animalia
Phylum
Chordata
Class
Order
Scorpaeniformes
Family
Scorpaenidae
Genus
Pterois
Species
P. volitans
Lionfish use their broad fins to herd prey into tight spaces before striking.
Their spines are venomous, but the fish do not attack people on purpose.
A female lionfish can spawn many times in a year.
Lionfish can swallow prey surprisingly large for their body size.
In the Atlantic, lionfish have spread quickly because they have few natural enemies there.
The red-and-white stripes warn other animals to stay away.
Select a question to reveal the answer.
Red lionfish are native to the Indo-Pacific, but they also live as an invasive species in the Caribbean, Gulf of Mexico, and western Atlantic.
They are carnivores that eat small fish, shrimp, crabs, and other young reef animals.
Yes. Their long spines carry venom that can cause a very painful sting.
In the Atlantic they reproduce fast, eat many native reef fish, and face fewer predators than they do in their natural Indo-Pacific range.
No. Red lionfish are generally listed as Least Concern, but in some places the bigger problem is that they threaten other reef animals.
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