Part of the swarms of invasive Volitans Lions swept north to Long Island and collected by Todd Gardner of the Long Island Aquarium - image by Todd Gardner / LONG ISLAND AQUARIUM

Part of the swarms of invasive Volitans Lions swept north to Long Island and collected by Todd Gardner of the Long Island Aquarium – image by Todd Gardner / LONG ISLAND AQUARIUM

This excerpt first appeared in CORAL Magazine’s July/August 2014 issue, pages 9-12. Be sure to see the full issue for several additional stories on this topic.

As [the July/August 2014 CORAL Magazine] cover says, it is now official that the most-popular genus of lionfishes in the aquarium trade will, on August 1st, 2014, no longer be legal to import into the State of Florida.

Punishment for anyone caught bringing a Pterois sp. lionfish into the state will be subject to conviction of a First Degree Misdemeanor with a penalty of $1,000 and/or up to one year in jail. The intent of the new rule banning Pterois species lionfish is that it is to be applied to importers, wholesalers and retailers who are acquiring the lionfish for resale, not for private individuals who already have them in their aquariums. However, if a private individual buys a banned species from a business in another state (either over the Internet or by driving it in themselves), that aquarist is then doing the importing and would be subject to full criminal treatment in County Courts.

Florida cares, in part, because these invaders are eating everything from tiny, endangered baby Goliath Groupers to juvenile Stone Crabs, Pink Shrimp, and Spiny Lobsters. Voracious lions on the loose are far more than a nuisance.

In this issue CORAL Senior Editor Ret Talbot takes a close look at the new rules as well as the origin of the plague and a possiblity that even worse environmental news is yet to come if lionfish start moving into brackish or even fresh waters. Think Chesapeake Bay as climate changes or even the Amazon River watershed. As responsible aquarium keepers I believe we all need to follow this story and do everything we can to be sure it doesn’t happen again.

—James Lawrence
Shelburne, Vermont


Is banning imports of lionfishes from the genus Pterois just grandstanding, as some say, by Florida’s governor-appointed Fish and Wildlife commissioners—slamming the barn door shut, loudly and publicly, after the horses have bolted? Is there scientific justification for the ban? Do objective marine biologists think it will do any good?

These questions about how to deal with the worst manmade range extension of a marine fish species in history have been swirling around recent legislative and administrative efforts in Florida to ensure that no more non-native, invasive lionfishes enter this state’s waters. The vast majority of the public thinks a ban should be imposed, and that’s clearly one reason why lawmakers got involved during this past legislative season.

Florida is reported to spend half a billion dollars annually on combating invasive species. It’s a war, and if a casualty of that war is a small percentage of a relatively small hobby, that’s just fine with most of the general public. In fact, many aquarists who are aware of the facts believe the ban is justified and support it; several aquarium trade groups have also come out in support of it.

On the other side of the argument is a much smaller group comprised of aquarists, aquarium industry professionals, and some scientists who are not convinced the ban is necessary. Their responses to the new rules banning imports of Pterois lionfishes run the gamut from anger to tempered frustration. Some aquarium professionals feel the aquarium trade is being unfairly targeted and that the ban will do little but cause them economic harm.

Some scientists question the decision to ban all Pterois lionfishes because there is no hard data suggesting that all species in the genus pose the same level of risk as the two that are currently invading the western Atlantic and Caribbean. Even though some of those scientists expressed their concerns during opportunities for stakeholder input prior to the approval of the final rule banning the genus in mid-June, most of them now feel that they’ll take what they can get—even if that means a ban on the entire genus—because getting the lionfish invasion under control is such an important issue.

Against this backdrop, those of us who have worked on this issue at CORAL Magazine are taking a deeper look into the questions of whether or not the ban on all lionfishes from the genus Pterois is justified and what it could mean if followed to its logical conclusion.


Lionfishes belong to a family of fishes called Scorpaenidae, commonly called scorpionfishes or rockfishes. There are currently more than 200 species in 26 genera. They are found in brackish, fresh (rarely), and salt water and distributed circumglobally in all tropical and temperate seas. Members of this family possess dorsal, anal, and pelvic fins, some of which contain venom glands, making them less appealing to many predators. Most scorpionfishes are found on or near the bottom, where they feed on crustaceans or other fishes.

Many taxonomists consider the family Scorpaenidae to have three subfamilies: Scorpaeninae, Sebastolobinae, and Pteroinae. It is this last subfamily, which includes the so-called lionfishes and turkeyfishes, that is at the heart of this debate. Pteroinae currently contains five genera: Pterois, Dendrochirus, Parapterois, Ebosia, and Brachypterois. The most common genus imported for aquaria is Pterois, but species from the genus Dendrochirus (commonly called the dwarf lionfishes) are also very popular aquarium animals. Brachypterois species are occasionally seen in the trade.

Given the large number of scorpionfish species, the ongoing taxonomic debate about how the various genera and species are related, and the fact that at least three genera in the subfamily Pteroinae are imported for the aquarium trade, banning the entire Pterois genus—or, from another perspective, stopping short of truly banning all lionfishes—seems to lack logic and scientific justification.


The smallest lionfish from the genus Pterois is the Mombasa Lionfish (P. mombasae). It reaches a maximum size of 8 inches (20 cm) TL. The largest species from the genus Dendrochirus is the Zebra Turkeyfish (D. zebra). It reaches a maximum size of 10 inches (25 cm) TL. These genera are considered to be very similar—so similar, in fact, that some scientists have argued they should be one genus. For example, in “Molecular phylogeny of the lionfish genera Dendrochirus and Pterois,” a 2003 paper published in the journal Molecular Phylogenetics and Evolution, Kochzius et al. write:

“Even though not all species of the genera Dendrochirus and Pterois could be considered in the present molecular phylogeny, it suggests that separate genera are not warranted. This supports the classification of Dendrochirus spp. as members of the genus Pterois by Klunzinger (1870), Günther (1873), and Beaufort and Briggs (1962).”

Despite these similarities, the rule approved unanimously by the Florida Fish and Wildlife Conservation Commission (FWC) in mid-June drew a stark distinction between P. mombasae and D. zebra and their genera. Effective August 1, 2014, it will be illegal to import the Mombasa Lionfish into the state, but the Zebra Turkeyfish will be allowed. Critics of the rule question the thinking behind banning one and allowing the other. Privately, they fear that the ban itself could set a precedent that has wide-ranging effects on the marine aquarium trade both in Florida and nationwide.


In instituting the ban, the State of Florida decided to include all members of the genus Pterois rather than just the two species that are invasive in Florida. The reason for the ban on imports of the Mombasa Lionfish and all other lionfishes of the genus Pterois is that the two largest members of this non-native genus are currently considered established and invasive in Florida waters. The Volitans Lionfish (P. volitans) and the Devil Firefish (P. miles), 15 and 14 inches (38 and 35 cm) TL, respectively, are wreaking havoc on native species throughout the western Atlantic by ravenously targeting small and juvenile native fishes.

Most experts familiar with the western Atlantic lionfish invasion believe these fishes were first introduced to Florida waters by aquarists who released them, either due to the destruction they were causing in their owners’ aquaria or because the fishes outgrew the aquarium altogether. The new FWC rules, several of which have gained widespread support, are meant to help control these invasive fishes in Florida waters.

Most stakeholders agree that banning imports of the Volitans Lionfish and the Devil Firefish is appropriate. Not only will such an action eliminate future introductions, but it will also provide additional economic incentive for harvest of the two species in state waters to fill the demand of Florida-based aquarium fish importers and wholesalers, who will no longer be able to import these popular aquarium fishes from their native range. While most support FWC in banning the two invasive species, other stakeholders take issue with the rules’ definition of a lionfish as “any finfish of the genus Pterois.” This concern, along with several others, was voiced at every opportunity for public comment preceding the mid-June decision, but, unlike other concerns, has never been addressed formally or publicly by FWC staff.

Critics of the new rules point out that no species of lionfish from any genus has ever been reported in Florida waters except for the Volitans Lionfish and the Devil Firefish. Banning the import of the eight other species of lionfish in the genus Pterois would amount to “guilt by association” instead of a decision based on sound science. An FWC spokesperson said, “The species that belong within this genus [Pterois] all have similar biology and characteristics to the two species that have been successful in invading Florida waters. This indicates that others within that genus might be successful.”


Those critical of the import ban on Pterois lionfishes worry that banning eight marine species because of the risk they might pose is opening the gate to a very slippery slope. Further, they contend that several of the popular lionfish species now banned from import pose little risk because of their much smaller maximum size. The smaller size, they argue, makes aquarists less likely to release them and lessens the risk they may pose to native wildlife. Some have also suggested that these other species may have a lower thermal threshold than the highly adaptable Volitans Lionfish and Devil Firefish, species so similar they are sometimes placed together in the Volitans/Miles Species Complex. Currently there is not enough published, peer-reviewed science to support this claim. Critics of the ban say public, data-driven risk assessment is essential before such decisions are made.

Of course, undertaking a thorough risk assessment of every non-native marine fish species that has already been spotted in Florida waters would take more resources than the state would be able to spend in order to allow a hobby to continue unchanged. While the aquarium trade in Florida is a valuable industry, much of its economic worth comes from ornamental fish farming, not from the import and resale of non-native marine species.

If one agrees with the logic of banning all species in the genus Pterois, including the diminutive Mombasa Lionfish and the Radiata Lionfish (P. radiata), which reaches a maximum size of only 9.4 inches (24 cm) TL, it follows that many more species of popular marine aquarium fish should also be banned from import. If FWC feels the risk is so great that the small Pterois species should be banned simply because they are in the same genus as the much larger and invasive Volitans Lionfish, it seems equally justifiable to ban the import of the Zebra Turkeyfish, Dendrochirus zebra, which is larger than the Mombasa and Radiata Lionfishes and, according to the scientific literature, so closely related that it could possibly be reclassified and put in the genus Pterois.

If we’re going to ban lionfishes from the genera Pterois and Dendrochirus, then what argument exists against banning the third genus in the subfamily Pteroinae that is occasionally imported for the aquarium trade? Although it is not imported often, scientists studying the genetics of the western Atlantic lionfish invasion have concluded that the entire invasive population likely resulted from very few original introductions.

Applying the logic FWC has employed in banning all species of the genus Pterois would mean that they should also be considering import bans on many other species of non-native marine fish from other families that, based on the published literature and case studies, pose a much greater risk than some of the lionfishes. There are now more than 30 other non-native marine aquarium species listed as either “reported” or “established” in Florida waters as a result of “probable aquarium release”—species like groupers from the family Serranidae, which we suspect could devastate native fish populations once established.

This is not the first time FWC or other state or federal wildlife managers have banned a species because of the risk it might pose, but this may well be the first time that such a decision will lead to additional consequences with wide-ranging implications for the aquarium trade and other fisheries industries, both in Florida and beyond. Given the logic behind the new rule banning the importation of Pterois lionfishes, it’s not too difficult to envision a ban on the importation of all non-native marine fishes that are currently imported to Florida for the aquarium trade. It is our hope that this never comes to pass, that aquarists will demonstrate greater responsibility for policing themselves and not releasing exotics in the wild and that common sense will prevail in the regulatory bodies. Keeping aquaria provides economic returns to tens of thousands tens of thousands (many of whom live in developing island nations, where the aquarium trade can provide economic incentive to preserve reefs), untold joys and family pastimes to millions, and education on the beauty and wonder of aquatic ecosystems to our society. We need to know what we have before we can work with passion not to lose it.

—Ret Talbot,
Rockland, Maine

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Image Credits:
Juvenile P. volitans collected in Long Island, NY – Todd Gardner / LONG ISLAND AQUARIUM

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