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Home › Sea Life › Marine Species › Vertebrates › Lion Fish

Interesting Facts about Lionfish

[Lionfish Phylum: Chordata] [Class: Actinopterygii] [Order: Perciformes] [Family: Scorpaenidae]

They are beautiful to look at but they cause devastation in coral reef ecosystems. They are particularly destructive along the eastern coastline of northern America and the Caribbean islands.

This guide contains essential facts about the lionfish genus Pterois, including where they are found, what they eat, and how these venomous marine fish reproduce.

Lionfishes Geographic Range and Habitats

Pterois volitans and Pterois miles are widespread and native for most of the Indo-Pacific, especially the Red Sea, Indonesia, and Australia.

But, the lionfish species has become invasive in the western Atlantic Ocean, and in particular:

• Southeast U.S. coast (North Carolina to Florida)
• The Gulf of Mexico
• Parts of South America's northern coastlines
• The Caribbean Sea (including the Bermuda region)

A spread that first began in the mid 1980s (most likely from aquarium releases) now occupies more than 7 million square kilometers of the waters across the western Atlantic.

One of the reasons for the uncontrolled spread of invasive lionfishes is that they are extremely adaptable and they can occupy a broad range of marine habitats, including:

• Artificial Reef Structures (such as sunken shipwrecks and oil rigs)
• Seagrass Beds and Mangroves (lionfish juveniles use them for nursery areas)
• Coral Reef Formations (shallow to mid-depth reef networks shallower than 50 metres provide the ideal habitat for a fish species that hovers near coral heads, overhangs, and ledges)
• Deep Reefs (some species of lionfish - such as the deepwater firefish - can tolerate depths approaching 300 metres)

Lionfish Characteristics and Behaviour

Governmental agencies in some of these hotspots suggest local divers should hunt them down and kill as many lionfishes as possible to help reduce the problem.

There is an added bonus for the killers. Despite being a venomous marine fish, they are often used in culinary dishes, especially in the United States and Japan.

Here's the thing:

The main problem is that lionfish reproduce at high levels, partly because they have few natural predators in the wild.

Hence, they sit close to the peak of their food chain. They enjoy the unchecked control of their population which creates some disastrous consequences as delicate coral reefs become imbalanced.

What Do Lionfish Eat?

They are extremely skilled hunters that prey aggressively on invertebrates and most types of mollusks and marine crustaceans.

In fact, these opportunistic carnivores can even swallow several different fish species as one complete meal. Some of the other food sources eaten by lionfish in the ocean include:

• Bivalves (e.g., clams, oysters)
• Crabs
• Damselfishes
• Groupers
• Krill
• Lobsters
• Parrotfish
• Shrimps
• Snappers
• Squid
• Wrasses

Pro Tip: Our diving injuries help guide contains more information about lionfish sting symptoms and treatment, including why this type of puncture injury happens.

Types of Lionfish Species

How Do Lionfish Reproduce?

When they spawn, the female lionfish ejects large clusters of eggs at once (up to 12,000 eggs). The male fertilises them, and the newborn fish hatch around thirty-six hours later.

Lionfishes have no fixed breeding season, and females can repeat the cycle monthly. Juveniles can swim very well after only a few days.

They are capturing and eating small prey during these first few days of life, and their metamorphosis to the adult stage happens around day thirty of their development.

Detrimental Invasions by Lionfish

Characterised by their long spiky fin rays that contain venom, the hostile lionfish is one of the most invasive and aggressive reef fish species. Their venomous spines deter predators from attacking them in their environment.

The poison is fatal on their prey but rarely kills humans. If the sting affects a diver, the most likely symptoms are localised pain, nausea, and fever.

Studies show that lionfish species are responsible for the eradication of most reef fish in the Caribbean and other areas.

Groupers are showing signs of eating lionfish, but the general overfishing of the grouper fish species is slowing down the progress of its natural predatory activities.

This is why some agencies are asking divers, anglers, and snorkelers to assist the controlling programs of lionfish populations in designated areas.

But wait - there's more:

The lionfish is a spectacularly photogenic and unmistakably popular species. Nonetheless, in most of the Caribbean and Atlantic marine ecosystems, infiltration and destruction by lion fishes is so severe they have reportedly ravaged and decimated around 80% of the reef species.

Scuba divers are trying to balance the problem by actively hunting, catching, and killing large numbers of lionfish in these areas.

The environmental and governmental agencies strongly encourage and support underwater hunters to assist the mass cull. As a bonus, lion fish are considered a tasty meal by many.

Why Lionfish Invaded the Environment

Unconfirmed theories of how the species invaded the local environment blame the devastating hurricane Andrew in 1992. One suggestion is that lionfish entered south Floridian waters via a damaged fish aquarium.

Another theory centers around the same hurricane in which the species were accidentally released. Other reports claim that they were deliberately set free.

Uncontrollable Lionfish Reproduction

Four crucial and somewhat surprising factors have influenced the uncontrollable rate of reproduction by lion fish.

1. The Atlantic and Caribbean delicately balanced reef ecosystems do not support a natural lionfish predator. The Grouper is considered a natural predator of lion fish species but groupers rarely exist in large enough groups to make a significant difference. Sitting at the top of the food chain unchecked by a natural hunter, the lionfish population thrives on abundance and imbalance.
2. Lionfish are renowned for their voracious and indiscriminate appetite resulting from their aggressive hunting skills. They will swallow huge amounts of different reef fish species and marine invertebrates mollusks in one single meal.
3. They breed and spawn at a tremendously high rate and the female lionfish often releases more than 10,000 eggs each time. They have no typical breeding season but reproduce monthly in most environments. After the male fertilises the eggs they hatch and begin swimming within three days. They are now competent feeders capturing small prey. The juveniles metamorphose to adults within three to five weeks.
4. Lionfish are aggressively hostile, extremely territorial, and venomous. Their long spines contain a venom which is deadly poisonous to its prey but not usually fatal to humans. Injured divers from lionfish stings may suffer nausea and fever symptoms and should seek medical attention.

Help Catch and Kill Lionfish

Scuba divers, spearfishers, anglers, and snorkelers can help to catch and control lionfish populations in affected regions of the world.

Local programs aim to slow down the devastation caused by the unwelcome intruder and allow reef ecosystems to recover from lionfish invasion.

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