DESCRIPTION: There are two species that are problematic in U.S. waters.
Red lionfish (Pterois volitans) The body of this lionfish species is white or cream colored with red to reddish-brown vertical stripes. The vertical stripes alternate from wide to very thin (with the thin stripes being more numerous) and sometimes merge along the flank to form a “V”. Coastal populations are generally darker, sometimes almost black in estuaries. The red lionfish is also characterized by its greatly elongated fin spines. It has 13 dorsal spines, 10 - 11 dorsal soft rays, 3 anal spines, and 6 – 7 anal soft rays. The membranes of all fins are often spotted. The maximum total length of adults is 15 inches. Maximum adult body weight is 2.4 – 2.6 pounds.

Devil firefish (Pterois miles) Although it appears very similar to the red lionfish in size and color, the devil firefish has fewer dorsal and anal fin rays. Devil lionfish usually have 10 dorsal-fin rays and 6 anal-fin rays whereas red lionfish usually have 11 dorsal-fin rays and 7 anal-fin rays. Recent genetic work using mitochondrial DNA was unable to reveal whether P. miles and P. volitans are distinct species or two populations of a single species; nevertheless, genetic studies have confirmed that about 97% of the Atlantic population of lionfish consists of P. volitans, while only 7% is P. miles.

PATHWAYS/HISTORY: Lionfish species are widely distributed throughout the South Pacific and Indian Oceans. The native range covers a very large area from Western Australia and Malaysia, east to French Polynesia and the United Kingdom’s Pitcairn Islands, north to southern Japan and southern Korea, and south to Lord Howe Island off the east coast of Australia and the Kermadec Islands of New Zealand. In between, the species is found also throughout Micronesia. The lionfish was first detected in Florida in 1990’s and are now well established throughout most of the Caribbean to Cape Hatteras, North Carolina. Juvenile lionfish have also been found as far north as New York and Rhode Island. These fish are not expected to be able to over winter in the cold northern waters; however, warming ocean conditions may permanently expand the range of this fish along much of the eastern coast of the United States. The lionfish invasion in the North Western Atlantic and Caribbean represents one of the most rapid marine invasions in history. A recent study found a tenfold increase in their abundance from 2004 to 2008 in parts of the Atlantic and Caribbean. Their initial introduction is thought to have occurred during Hurricane Andrew in 1992 when at least six lionfish escaped from a broken beachside aquarium near Biscayne Bay. The continued release of unwanted lionfish by hobbyists is thought to be a cause of additional introductions and the range expansion of the lionfish.

RISKS/IMPACTS: The diet of the lionfish includes over 40 species of fish and crustacean species; this broad diet suggests that this invasive species may become a real threat to many native reef fish populations through direct predation as well as competition for food resources with native piscivores. Researchers have reported that within a short period after lionfish are introduced into a new area, survival of native reef fishes declines by about 80 percent. Further, the voracious feeding behavior of the lionfish may impact the abundance of ecologically important species such as parrotfish and other herbivorous fishes that keep seaweeds and macroalgae from overgrowing corals. The dorsal- and anal-fin spines of the lionfish contain potent venom that can administer a painful sting. When threatened, the lionfish will arch its back, point its dorsal spines at the aggressor, and swim forward rapidly in order to inflict a sting. Consequently, the lionfish poses a threat to fishermen, divers, and wildlife inspectors. Symptoms of the sting may include: extreme pain, swelling, redness, bleeding, nausea, numbness, joint pain, anxiety, headache, disorientation, dizziness, nausea, paralysis, and convulsions.

MANAGEMENT: Although it is highly unlikely that lionfish will be completely eradicated, efforts are in place to control lionfish abundance. Federal, state and local partners, as well as divers and dive operators, public aquaria, and foreign fisheries departments have been working together to document lionfish sightings and remove the fish when possible. Divers are encouraged to report any lionfish they encounter. Fishermen are also helping to curb lionfish numbers. They are reported to be excellent table fare and their consumption is being promoted throughout the Caribbean as a subsistence fishery. The venom is only found in the spines, not the flesh, and cooking destroys any residual toxins. However, extreme caution is urged when handling these fish, as their spines can inflict a powerful sting.

WHAT YOU CAN DO: Never release aquarium fish into the wild. Report any sightings of lionfish on the Aquatic Nuisance Species Task Force Sightings Report Form . General aquatic nuisance species prevention: Do not release aquarium pets or live food into the environment. Never dump live fish, e.g. baitbuckets, from one body of water into another body of water. Always drain water from your boat, livewell, and bilge before leaving any water access.

PROFILE CREDIT: Susan Pasko, NOAA - IMAGE CREDIT: Don DeMaria