Lionfish are among the flashiest-looking fish you’ll see navigating the undersea reefs. They sport a spectacular display of colors and prominent fins that will surely lure you in. However, behind their dazzling appearance lies a potent threat that is proven fatal to humans. To add to their nasty side, tend to be invasive animals in non-native habitats, destroying some perfect ecosystems.
When a lionfish is hungry, you better not get in their way! Once their spines face forward, you better hide! These amazing fish can eat eight times their body weight, and their stomachs can expand to as big as 30 times their normal size. That big!
However, they’re not one to start a fight. They are not aggressive and usually avoid potential predators. Once they’re content with where they are, they don’t bother to travel. Once settled, they can mate at any time they want. Female lionfish lay up to 2 million eggs in a year or up to 30,000 eggs in less than a week. The reproduction of lionfish increases in warm waters, while those who stay in colder water reproduce only three to four times a year.
Learn more about these vibrant yet dangerous animals with these spectacular lionfish facts.
- In the wild, they can live from five to 15 years.
- There are 18 known species of lionfish within two genera, Pterois and Dendrochirus. Genera is the plural of Genus, a taxonomic rank used in the biological classification of living and fossil organisms.
- Pterois has 12 species, while Dendrochirus (dwarf lionfishes) has six.
- Adults average around 13 to 18 inches (33 to 38 centimeters) long, and some may even grow up to 18.5 inches or 47 centimeters long.
- They typically inhabit depths of about 164 feet (50 meters), but they can also live in depths of up to 984 feet (300 meters).
- Lionfish are carnivorous fish.
- They’re mainly nocturnal, but some populations are most active during the day.
- They live in marine environments and prefer warm, tropical regions.
- They have fan-like pectorals and spiny dorsal fins.
- Lionfish go by many different names. Some people may refer to them as butterfly-cod, firefish, zebrafish, turkeyfish, or even tastyfish.
- The Latin genus name Pterois comes from the Greek word pteron, which means wing. Meanwhile, Dendrochirus originates from the Greek words dendron or tree and cheir or hands, referring to their tree-like markings.
- They belong to the family Scorpaenidae, which includes the scorpionfish, dragonfish, and stingfish. This family has some of the world’s most venomous fish.
- Their scales are cycloid, which means that the scales are elliptical in shape, and have smooth edges.
- During the day, they typically rest in the crevices of rocks and corals. They may also hide in artificial reefs like shipwrecks.
- Lionfish babies, also known as fry, are typically less than an inch or 2.54 centimeters long.
- Similar to anglerfish, some lionfish have tentacles above their eyes and below their mouths. They use these tentacles to attract and lure prey close to them.
- Because of their attractive coloration, these fish are popular in the aquarium trade.
- During reproduction, the males change color to a much darker hue, making their stripes less visible. On the other hand, females become paler in color.
- These fish are typically solitary, but males will often band together with multiple females during courtship. The groups may consist of three to eight fish.
- In the 2004 American animated film Shark Tale, Angelina Jolie voices a seductive female lionfish.
They have venomous fin spines.
One of the most important lionfish facts to know about is that they are venomous. Although they are among the least venomous species in their family, they can still deliver a significantly dangerous toxin.
Lionfish have a total of 18 sharp spines on their dorsal, pelvic, and anal areas. Each of these spines has a pair of venom glands at its bases, and loose sheaths cover each spine. When the spines penetrate the flesh of a would-be predator, the sheath gets pushed down and compresses the venom glands, delivering the toxin.
Lionfish use their venom as a purely defensive strategy, and they don’t use it to hunt their prey. Their venom has neuromuscular toxins comparable to cobra venom. It can cause severe pain that can last for days. Additionally, it can cause redness, swelling, bleeding, numbness, nausea, convulsions, headaches, heartburn, diarrhea, and disorientation. In rare cases, the venom can also result in temporary paralysis, organ failure, or even death.
The venom is rarely fatal to healthy adults but can be fatal to children, the elderly, and those with a compromised immune system. Those who have allergic reactions to their venom can also go into anaphylaxis, which can also be fatal.
When a person gets stung by a lionfish, it’s highly advisable to remove any remaining spines on the skin. Afterward, the wound must be cleaned with soap and water. If possible, it’s best to apply hot water around 100–110 °F (38–43 °C) to the area for 15 to 20 minutes.
Applying heat is advisable, because the venom contains proteins that denature from heat, and the non-scalding hot water can therefore prevent them from spreading into the bloodstream.
Lionfish display a warning coloration.
Lionfish notably display vivid colors of red, white, and black, as well as striped patterns that make them easily distinguishable in reefs. They also sport large fins which fan out noticeably. As their appearance makes it difficult for them to blend in with their surroundings, they opt for another defense strategy. These ornate fishes display a trait that scientists call aposematism. This means that they display visible features to warn potential predators that they’re dangerous and not worth attacking. In this case, showing vivid colors is a warning that they are venomous. The adaptation is also common in many other animals such as insects, frogs, and snakes.
Lionfish are territorial.
Although they are generally not aggressive and tend to shy away from predators, lionfish can display territorial behavior. Male lionfish are particularly territorial, and they become aggressive especially when courting females. They may approach potential threats with their spines facing forward, so divers must always treat them with caution. These territorial fish do not travel very far from their territories once they establish their residence.
They are skilled hunters.
Lionfish are ambush predators that use their large fins to sweep the substrate and drive their prey out of hiding. When their prey emerges, they then corner it and swallow it whole using their impressively big mouths.
They can also blow jets of water from their mouths to disorient their prey before eating them. The jets of water could also make small fish face the lionfish and swim towards their mouths instead of away from them. This makes hunting more efficient for these flashy-looking fish.
They eat a wide variety of fish species, as well as shrimps, isopods, crabs, and other invertebrates. Young individuals eat more crustaceans and gradually increase their intake of fish as they approach adulthood. However, they aren’t particularly picky eaters and are willing to eat any animal that can fit into their mouths.
It’s no surprise that lionfish are voracious eaters. In fact, they can eat an average of 8.2 times their body weight in a year. They can consume one or two fish in a minute, and their stomachs can expand to as much as 30 times their normal size.
They have few natural predators.
Lionfish are top predators in their natural habitats, and they have few predators themselves. However, sharks, groupers, cornetfish, moray eels, and frogfish may occasionally feed on them. Juvenile lionfish are particularly vulnerable to predation, so they spend most of their energy eating to grow bigger. Records of parasites have also been rare, but their documented parasites include leeches and isopods.
Lionfish sometimes may cannibalize each other in captivity.
There have been multiple studies on cannibalism in lionfish populations, but most evidence comes from anecdotes and experimental conditions. Some researchers noted that while captive specimens commonly practice cannibalism, this may not reflect their diet in the wild.
Female lionfish can lay up to 2 million eggs in a year.
Lionfish readily mate at any time of the year, and they are prolific breeders. A female can lay up to 10,000 to 30,000 eggs every four days —or up to 2 million eggs in a year. They tend to reproduce more in warmer waters, however. Those who live in colder waters can only spawn 3 to 4 times a year.
Their mating ritual is complex and involves what some may describe as a dance between a male and a female. The couple repeatedly dives down to the substrate and proceed to face each other. After this, they perform a waltz-like dance, circling each other while slowly rising to the surface.
As the couple approaches the surface, the female lays a pair of mucus-filled egg clusters. These egg clusters contain as many as 15,000 individual eggs. When the eggs rise to the surface of the water, the male releases his sperm to fertilize them. Embryos begin to form just twelve hours after fertilization, and they hatch in 36 hours.
Lionfish are invasive species in some regions.
Because they lack natural predators and can eat a wide variety of food, lionfish can readily live and reproduce in non-native environments. Their fast reproduction and massive appetites also make them quite a nuisance to ecosystems where they are not native. They tend to eat up most of the prey animals, including the herbivorous fish that control algae populations, leading to disruption of coral growth. They also compete with other predators and shake the food chain, causing more significant damages to coral reef ecosystems.
Most of the invasive fish come from captive specimens that have been released in the wild, either intentionally or unintentionally. Perhaps aquarium keepers released them in the wild because they got too big for their aquariums or had an appetite that was too great to overcome. Now, lionfish have successfully invaded the Caribbean Sea, the western Atlantic, and the Mediterranean Sea. Some scientists even state that they are the most aggressively invasive species on Earth. They fear that their invasion could be disastrous for ecosystems already struggling with water pollution, sedimentation, and climate change.
Some conservationists tried to train reef sharks to eat lionfish.
To somehow curb the lionfish devastation, many conservationists attempt to limit their populations in non-native areas. One of the weirdest methods of population control is training sharks to kill and eat these invasive fish. Sharks do not seem to take damage from the venomous spines of lionfish, and some viewed this as an opportunity to alleviate the problem regarding this invasive species.
In 2011, park officials of the Roatan Marine Park or RMP at the Republic of Honduras attempted to train Caribbean reef sharks to see the invasive fish as prey.
Although this seemed like a good plan at first, it actually created another problem. To train sharks to see lionfish as prey, divers had to hand out the remains of the fish to the sharks. The sharks had gotten used to divers handing out food that the sharks began to act aggressively towards divers because they expected handouts.
They are edible, and eating them is even encouraged!
Despite their dangerous venom, lionfish can be edible. Because they only deliver venom through the spines in their fins, lionfish are perfectly safe to eat if the cook removes the venomous spines. They reportedly make tasty food items, and some describe the texture of their meat as tender and buttery.
Due to their current status as invasive species, some conservationists actually encourage the consumption of this fish. In 2010, the National Oceanic and Atmospheric Administration (NOAA) launched a “Lionfish as Food” campaign to encourage people to eat and hunt this invasive species. Because humans are currently the most effective predators of these fish, the campaign proves successful in reducing lionfish populations. Who knew that protecting the environment could be so tasty?