The Anatomy of an Invasion: Lionfish

Red Lionfish (Pterois volitans)

Red Lionfish (Pterois volitans)

As iconic ornamental marine fish, Pterois spp. are coveted for their unique beauty which is bookended by elegant (but venomous), banner-like finnage. Native to the Indo-Pacific region, lionfish were reportedly discovered in South Florida as early as 1985 with sightings increasing dramatically along the southeast United States coast in the early 2000s. Now their invasive range encompasses much of the East Coast of the U.S as well as the Gulf of Mexico and Caribbean Sea.

Worth noting is that while it’s commonly known as the lionfish invasion, it doesn’t include all species of Pterois. The vast majority are P. volitans, and the remainder are P. miles.

Who let the lions out?

The most widely accepted cause of the invasion is rooted back in 1992 when Hurricane Andrew hit South Florida. A private aquarium was reportedly destroyed, which allowed a small group of lionfish to escape into Biscayne Bay. According to biologists, these fish likely released floating egg sacs, which rode the Gulf Stream, precipitating the scale of the invasion.

While this is certainly plausible, other speculations include home aquarists releasing specimens into the wild and less-than-ethical dive operators “enhancing” natural reefs by releasing lionfish for clients to spot. I tend to believe it may be a combination of all of these.

Environmental impact

Although cumbersome in appearance, P. volitans and P. miles are skilled and aggressive predators. These great hunters decimate native populations of reef fish and invertebrates that don’t recognize the “new kid on the block” as a threat. In addition to their healthy appetites, lionfish grow and reproduce faster than most Western Atlantic native species.

The problem is compounded by a lack of natural predators in this region. Sharks, groupers, barracudas, and other large predators capable of consuming lionfish don’t readily recognize the ornate creature as a suitable meal. Thankfully, strides have been made in “teaching” predators to look at lionfish as prey throughout the invasive range. With success in these efforts throughout the region, reports of lionfish predation seem to have become more common.

What can you do? (The Four E’s)


If an immediate impact is your goal, grab a spear or sling and go hunting! I always do my part while diving throughout the Florida Keys and Caribbean, and encourage fellow divers to do the same. As lionfish are invasive species, culling efforts are supported and promoted throughout the affected range. In fact, “lionfish derbies” have gained popularity by turning eradication efforts into a sporting competition.

The Fish and Wildlife Conservation Commission encourages folks to remove lionfish from Florida waters. Even better, no recreational fishing license is needed when using a pole spear, Hawaiian sling, hand-held net, or other various lionfish-targeted methods. For any location, please review the regulations before doing your part.


While their spines are venomous, lionfish meat is safe to eat. The Lionfish Cookbook received much attention and started the movement to advance “The Caribbean’s New Delicacy.” This book, published by the Reef Environmental Education Foundation, promotes lionfish as a great addition to restaurant menus and tables at home.


Inform fellow aquarists about the lionfish invasion. Though these invasive species have been calling Western Atlantic waters home for over 20 years, many people are still unaware of the plight they’re causing for native populations.


We encourage you to enjoy lionfish within the confines of your aquarium or throughout their natural environment in the Indo-Pacific. But never, under any circumstances, should you release specimens (be it lionfish, other non-native species, or native species) from your aquarium back into the wild. This has the potential to introduce not only an unwelcome visitor, but also disease that native inhabitants aren’t capable of coping with.

A lionfish speared by a diver

A lionfish speared by a diver

We can hope that with human intervention, such as those mentioned above, we’re able to buy time while the natural environment reaches equilibrium with these invasive species because lionfish are here to stay. This balance will be possible when small and juvenile reef inhabitants recognize the predator, larval-stage lionfish are consumed by smaller fish, and larger fish readily prey upon P. volitans and P. miles.

UPDATE: Read more about successes strides being made to control the lionfish invasion.


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About "Caribbean Chris" Aldrich

"Caribbean Chris" Aldrich is co-founder and Director of Saltwater Smarts, an avid SCUBA diver, and contributor to a live rock mariculture project in the Florida Keys. He has been an aquarium hobbyist for 20 years and his current aquarium is a 127-gallon Carib reef biotope.

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