Lionfish Facts

Why are lionfish a problem? Why do we need to hunt lionfish?

Lionfish are not native in the Western Atlantic Basin, which includes the Western Atlantic Ocean, Gulf of Mexico and Caribbean Sea, or the Mediterranean Sea where they are considered an invasive species.

Lionfish are native to the South Pacific, Indian Ocean and Red Sea. Their range covers a 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. They are found throughout Micronesia.

It is an established lionfish fact that the most likely cause for the invasion in the Western Atlantic Basin is aquarium owners who released their beloved pets into the ocean, while lionfish migrating through the Suez Canal is the most likely cause for their establishment in the Mediterranean Sea. Lionfish were first spotted off the coast of Florida in the 1980’s, disproving the common myth that they were released during Hurricane Andrew in 1992.

The current lionfish invasion is made up two species, Pterois volitans and Pterois miles, which are nearly indistinguishable outside of the lab. P. volitans accounts for nearly 93% of the total non-native, invasive lionfish population in the Western Atlantic Basin. The invasive lionfish population in the Mediterranean Sea almost entirely consists of P. miles.

Why we hunt lionfish?

We now know that we will never eradicate either population from the invaded areas. They are here to stay and we must all get involved to manage their population until nature finds a way to reach some balance. So far, divers are proving to be the most valuable tool in controlling the lionfish population in the shallow coastal areas that are accessible.Because they generally only eat small live fish, lionfish are only very rarely caught on hook and line, usually with a live shrimp.

Since they have no natural predator in the Atlantic, it’s an interesting lionfish fact that they are normally unafraid of approaching divers. However, they learn very quickly, and a lionfish that has had a speared shot at it previously will learn to avoid divers and hide deeper in their holes when they see the diver approaching. 

Lionfish facts

Lionfish are a part of the Scorpaenidae family. Commonly called scorpionfishes the family includes approximately 500 different species.

Adult-sized invasive P. volitans and P. miles average between 12 – 16 inches (31 – 40 cm) in length. The red lionfish and devil firefish is almost always striped in white, dark red, brown and black with dark spots found in orange fin rays and caudal fin (tail). It is not uncommon to find these fish turning almost entirely black.

Common names are lionfish, zebrafish, firefish, turkeyfish, red lionfish, butterfly cod, ornate butterfly cod, peacock lionfish, red firefish, scorpion volitans, and devil firefish.

The genus name “Pterois” is from the Ancient Greek word for “feathered” or “winged.” There are 10 species of lionfish in the genus.

The species name “volitans” is Latin for “flying” or “hovering” and “miles” is Latin for “soldiering.”

Lionfish are everywhere in the western Atlantic

Lionfish can reach adult size in approximately 2 years.

The largest recorded lionfish to date measured a little over 47.7cm or 19.5 inches and was speared near Islamorada, Florida in the United States. Our friends at Lionfish.co maintain an excellent list of current lionfish size records.

In lab studies, lionfish die when water temperatures reach 50 degrees Fahrenheit or 10 degrees Celsius. They are extremely freshwater tolerant and can survive brief periods with salinity levels as low as 4 ppm.

Using water temperature as the limiting factor of it’s potential non-native range, lionfish could theoretically live during the summer months as far north as Rhode Island, United States (where there are documented sightings) and as far south as Buenos Aires, Argentina (no known sightings yet).

Lionfish have been visually sighted down to depths of 1000 feet or 305 meters by submersible vehicles as well as having been rarely caught on hook and line at deep depths.

Another interesting lionfish fact is that lionfish have no known predators outside of its native habitat. There are reports that grouper, gray triggerfish and large eels have eaten lionfish in the Caribbean Sea, although these accounts usually involve a fish that has been chased or speared by a diver.

Predators that are known to hunt lionfish in their native habitat include cornetfish, grouper, large eels, bobbit worms, frog fish, other scorpion fish, sharks and others.

Lionfish breed like crazy

Female lionfish are sexually mature and will release eggs when they reach 7 to 8 inches in length, or approximately one year old. A female lionfish can shockingly release between 10,000 and 30,000 unfertilized eggs every 4 days year around, approximately 2 MILLION eggs per year, in South Florida and warmer Caribbean waters but possibly only spawn 3 to 4 months a year in colder waters. She will typically release 2 egg sacs that are between 1 and 2 inches long every spawn. It has been reported that the egg sac contains a chemical deterrent that discourages other fish from eating the eggs. The eggs sacs and larvae are distributed by ocean currents and wind which has driven their rapid increase in range.

 

Diver with large speared lionfish, courtesy of Gabriel Lopez Dupuis of Fundacion Clear this Fish Panam

Once its territory is established, a lionfish will not usually travel very far from its home. They also tend to be sociable, and we often see clusters or groups of them together. A trait of all invasive species is a tendency to prefer artificial habitat over natural habitat, and lionfish are no exception. We often find the greatest numbers around wrecks, bridge rubble, and other artificial dive sites.

A lionfish’s stomach can expand up to 30 times it’s normal volume, allowing it to eat prey just over ½ its own body size. If it can get its mouth around a fish, it will try to eat it!

Lionfish primarily hunt during the twilight hours of dawn and dusk. They have also been described as active hunters during periods of dim ambient light such as on overcast or notably cloudy days. Because of this, we often find them hiding during the day. They seem to prefer a ‘roof’ over their heads during the daytime, and the hunter is advised to look in all holes and caverns for them.

Lionfish are known to eat just about every marine creature in its range, by some estimates that includes over 70 different fish, invertebrates and mollusks.

A single small lionfish may reduce the number of juvenile native fish on any given reef by approximately 79% in just 5 weeks.

Interesting lionfish fact : One lionfish was recently found to have over 60 prey in its stomach.

Controlled studies have shown that a lionfish can go up to 3 months or longer without eating and only lose 10% of their body mass.

Lionfish have 18 venomous spines that are capable of easily penetrating human skin and delivering a very painful sting; 13 of these spines are located along the spine in the dorsal fins, there is one short spine in the leading edge of each of the pelvic fins and 3 short spines in the leading edge of the anal fin.

The venom is a protein-based combination of a neuromuscular toxin and a neurotransmitter called acetylcholine. The venom can be denatured (or rendered inert) by applying heat or freezing.

Recommended first aid for lionfish stings and envenomation include surfacing safely from a dive, removing any broken spines and disinfecting the wound then applying non-scalding hot water for 30 to 90 minutes. Monitor for signs of allergic reaction or shock and react accordingly. Seek medical treatment immediately. Click here for more information about first aid treatment for lionfish stings.

Although it can be extremely painful, there have been no known human fatalities as a result of a lionfish envenomation.

Lionfish are delicious

Yes, you can eat lionfish, they are venomous not poisonous. SeafoodWatch.org recently added lionfish to the ‘Best Species’ list of sustainable seafood with grocery chains like Publix and Whole Foods now selling them in their stores.

Ciguatoxins, the cause of Ciguatera Food Poisoning (CFP), have been found in a small sample of lionfish in VERY SPECIFIC AREAS where other reef predators are known to also carry the risk of ciguatera, however there have been no known cases of ciguatera food poisoning having been caused by eating lionfish to date.