There are many reasons why people choose to keep aquariums, but for many, the beauty and grace of a fish gliding through the water is an integral pleasure in the hobby. With its ornately flowing fins and delicate appearance, this is perhaps no better example of this than the lionfish of the subfamily Pteroinae. However, despite their appearance, these species are far from being the fragile creatures they might seem on first glance.


Depending on which specific taxonomic system you look at, there are around 20 different species in five genera that together comprise the subfamily Pteroinae. Two of these genera, Pterois and Dendrochirus, are commonly represented in the hobby, though occasionally a species from another genus will make an appearance. The most commonly seen lionfish include Pterois volitans (Volitans Lionfish), Pterois radiata (Radiated lionfish), Dendrochirus biocellatus (Fu Manchu Lionfish), Dendrochirus brachypterus (Fuzzy Dwarf Lionfish), and Dendrochirus zebra (Dwarf Zebra Lionfish).

Most lionfish are native to the reefs of the Indo-Pacific, though there are species naturally found in such areas as the eastern coast of Africa and Hawaii. In addition, there are invasive populations of Pterois volitans found throughout much of the western Atlantic and Caribbean from as far north as North Carolina south to Venezuela.

Keeping Lionfish

The first thing one notices about any lionfish is bound to be its long, ornate fins. These fins are also one of the biggest concerns in keeping lionfish for a couple of reasons. The first, and most notable, is that a number of these fins contain venomous spikes that you should be aware of whenever doing anything in close proximity to the fish. In addition, the way these fins spread out in most directions gives the fish an overall cubic shape that must be taken into consideration when planning out tank space. Unlike most fish that can easily maneuver a fairly narrow tank, the wide fins of a large lionfish will require plenty of room to be able to spread out.

Depending on which species of lionfish you look at, there is a wide range of sizes that makes them suitable to a wide range of tanks. The smallest dwarf species will stay as small as five inches, while a large Volitans can reach more than 18. If you are looking for a lionfish, also keep in mind that they are very fast growers, so avoid getting a young individual of one of the larger species if you do not already have plans on where to keep an adult sized fish.

Although they may not look it at first glance, lionfish are voracious predators with large mouths that will eagerly consume any prey it can swallow. They will readily eat live shrimp as well as any fish small enough to fit into its mouth. Many lionfish will only eat live foods when first acquired, though the most common species tend to be fairly easy to switch over frozen or dried foods.

Because of their large appetites, care does need to be taken when choosing tank mates. A common rule of thumb is to avoid fish that are less than half the size of the lionfish in order to try to avoid having the smaller fish become a meal. Conversely, avoid particularly aggressive fish such as large angels and triggers who have been known to harass lionfish. While I certainly will not make any promises on compatibility, large peaceful fish such as tangs, butterflies, and sweetlips would be good options to try, and many have had success with groupers.

By and large, lionfish are quite intelligent fish that can become extremely personable. After they adjust to living in your tank, they will frequently be out and about, exploring their environment and often even learning to beg for food. This can make tank maintenance a somewhat more alarming task, as they will often come check out what you are doing, forcing you to take great care to avoid startling them and ending up with a venomous spine in your hand.


Lionfish natively hail from reef environments, and as such can make good additions to reef tanks, provided you are not trying to keep small reef fish with them. They will not eat corals, though some have been known to find a favorite coral to perch on top of. Keep in mind, though, that any shrimp in your tank will quickly be eaten. The lionfish's large appetite leads to large amounts of waste that may increase the difficulty in keeping the pristine water most corals need in order to survive.

Whether or not you choose to actually keep corals with your lionfish, you should still keep an abundance of rock with plenty of caves and overhangs in order to mimic their natural habitat. Lionfish like to frequently take shelter in such tight spaces, particularly when they are first introduced to the aquarium. Fortunately, though, they will generally become more confident and soon spend much of their time out in the open water, though they may still retreat to their caves at times.


As mentioned earlier, lionfish do contain venomous spines that are used defensively. While they are not going to go out of their way to sting anything, they may do so if startled and you must always keep this possibility in mind whenever you are in a position where envenomation is possible. Fortunately, lionfish venom rarely causes serious problems, but a sting will result in significant pain and does carry a chance of complications. Young children, elderly adults, those with other health issues that may create complications if stung, and those with allergies or other severe reactions to venom (such as beestings) should be especially cautious.

If you do get stung, the best thing to do is seek medical attention. There is always the chance of further complications that can escalate to a medical emergency. A common first treatment is to soak the sting site in very hot (but not scalding) water for at least 20 minutes as there is evidence that this heat can denature the proteins in the venom.

The Dark Side of Lionfish – Invasion

With any current discussion of lionfish, it is impossible to not mention the elephant in the room. There has recently been much discussion on the problem of invasive Volitans Lionfish in the Atlantic and Caribbean. The Florida Fish and Wildlife Conservation Commission has even recently passed a ban on the import of all lionfish species into Florida that goes into effect August 1, 2014.

Unfortunately, the problem of the invasive lionfish is very real and it is a problem seemingly without solution. Volitans Lionfish are one of the largest lionfish species and can breed prolifically. They are also able to consume a huge number of other fish which threatens many of the native species in this area. There are very few other species in their introduced range that will actually eat lionfish, so there is little natural pressure keeping their population in check. However, there are ways we can help, including encouraging utilizing lionfish as a food fish (I hear they're delicious), increasing the numbers of people sport fishing for them, and increasing the number of lionfish caught from the Atlantic to be kept in the hobby (Segrest Farms will continue to offer as many Atlantic caught Lionfish as our customers want).

Nobody knows for sure how lionfish were originally introduced to this area, but the aquarium hobbyist is often the easy target for blame. As hobbyists, we have a responsibility to conserve the viability of our hobby. Doing so requires that we not only strive to protect the long term survival of the species we keep but also that we avoid abusing our hobby to the detriment of the environment. If we fail in these responsibilities, we not only risk irreparable damage to the world, we also open ourselves up for increasing levels of scrutiny and regulation that will damage our hobby. We now live in an age where almost any information we desire is available at our fingertips, so we must be prepared in our decisions. Before you buy any animal, take advantage of this information and ensure you are adequately prepared to care for the animal throughout its life. For more information on the responsibilities of the aquarium hobbiest, check out Habitattitude.


Lionfish can make a stunning centerpiece in any aquarium. With the wide range of species available in the hobby, you can find one to fit into all but the smallest of aquariums. While they do come with their own set of challenges (but really, what fish doesn't?), lionfish by and large are hardy species that do very well in a home aquarium. With their unmatched beauty and highly personable behaviors, they can quickly become one of your favorite fish.