Saltcorner: Article: Lions in My Aquariums

Lionfish belong in the “Order Scorpaeniformes” and “Suborder Scorpaenoidei” where they are members of the “Family Scorpaenidae” (Lionfish) in which there are thought to be six genera having about twenty-one described species. However, only a few constantly make it into the aquarium trade. Another six or seven show up occasionally and are sometimes misidentified. Naturally, most inhabit shallow lagoon and reef areas in the Tropical Indo-Pacific Ocean and Red Sea. However, some specimens of the Pterois volitans genus have been found in the Atlantic Ocean from New York’s Long Island south to North Calolina, Florida, and Bermuda. These have no doubt been introduced by humans, probably aquarium keepers who no longer could care for them for one reason or another. A much ill advised approach!

All have large eyes and mouths that fit well into their large heads, and with array of spectacular wing-like pectoral fins, are among the most bizarre looking fish in the ocean! And since these mostly reddish brown with irregular spots fish have an atrophied swim bladder, they only swim short distances and often rest on either the bottom or substrates of various kinds while waiting motionless for something tasty to swim close enough to be sucked into their huge mouth.

Because of their unusual body and fin shape, lionfish are among the most extraordinary looking marine fish that I’ve ever kept. They have also given me more pleasure in maintaining them than most other species and besides, have also received the most ‘Wows’ from awestruck on-lookers. In fact, I could probably write an article on just lionfish comments, especially those from children, who simply become mesmerized when seeing them! Additionally, I’ve found lionfish to be very hardy, long-lived, and disease resistant, which added to the pleasure that I’ve had in maintaining them in a variety of different aquarium environments.

But before you jump up with joy and say ‘got to have one of these,’ I should mention that lionfish have venomous fins. They have two venom (a neurotoxin) containing glands located at the base of each dorsal spine. When agitated or frightened these fish are capable of springing forward and injecting the offending party, whether that may be another animal or the hand that feeds them, with a very painful wound. The severity of the reaction depends on the individual stung. For humans, a moderate level of discomfort may only be experienced, while others may experience severe pain. A severe anaphylactic reaction may occur in some cases and require emergency medical treatment. If stung, immersing the wound in as hot as possible water that can be tolerated will help breakdown the venom and reduce the level of pain. Care is well advised when cleaning their aquarium or when feeding. In fact, I always used an egg crate shield when cleaning their aquariums. I simply sectioned off the portion of the aquarium I was cleaning with pieces of egg crate panel, thereby protecting myself from any harm. Those aquarists who have severe allergy reactions might want to skip trying to keep this fish, or at least take all the proper precautions when feeding or cleaning its tank. And any children in the household or visitors should also understand the dangers associated with these fish.

Those in the genera Dendrochirus and Pterois are of the most interest. In the genus Pterois, probably the most commonly seen is P. volitans and one of my favorites. It’s quite widespread in the Pacific Ocean, Indian Ocean, Red Sea, and has also been seen in the Mediterranean. Often called the Turkeyfish, or simply the Volitans Lionfish. I’ve also seen it occasionally called the Butterfly Codfish or Red Firefish. Its one of the largest lionfish, reaching about 15 inches (38 cm), and requiring ‘at least’ a 60 gallon tank to properly maintain it. I maintained my first specimen, about twenty years ago, in a 75 gallon tank along with a Hawaiian Dragon Moray (Enchelycore pardalis) and Niger Triggerfish (Odonus niger).

I fed it various types of fish flesh two to three times a week that were speared or hooked on the end of a long metal rod (made from a coat hanger). And let me emphasis, “long and metal” because I never could be sure what the other two inhabitants would do. Once, the eel actually broke the surface of the water to grab the tasty morsel before I could lower it into the water. Water went flying in all directions! And the trigger often had to be fed first as it had the speed and appetite that often demanded my attention before the much slower moving lionfish could be fed. And I must say, all respected the others space, and there were never any compatibility problems in this aquarium.

Even though their natural diet consists mainly of live small fish, shrimp, and crabs, such a diet is not practical or always feasible in our aquariums. Unfortunately some aquarists have turned to feeding small freshwater live fish, e.g., guppies, mollies, or goldfish feeders, as they like to watch their lionfish hunt their swimming prey. Bad idea, because these freshwater fish lack some important fatty acids. And where goldfish feeders are involved, keep in mind that they are not only NOT nutritious, but their cost will soon far out weigh the cost of the specimen being fed. Furthermore, feeder goldfish often carry many different bacteria, fungi, and protozoa that can cause parasitic and infectious diseases. They can also cause blockage in the digestive track, and/or kidney and liver damage in these species, which usually leads to the consumer's death. Therefore, lionfish should be trained to accept defrosted or freshly prepared ‘marine’ shrimp and/or various kinds of marine fish flesh.

Because of that, I have always made it a point to train my lions to take long strips of marine fish flesh. I would simply gently wave the strip back and forth until I had their attention. And once they realized that dinner was being served when the aquarium hood was removed, they patiently waited near the surface to grab anything falling into the water. I even collected small crabs and grass shrimp on my many trips to Mexico waters and placed them in the tank when arriving home. All enjoyed the chase and the extra special cuisine. And for those that live near the ocean where there may be fishermen bait shops, small marine ‘bait’ fish are often available. These make an ‘excellent’ foodstuff for these fish!

Other specimens over the years were maintained in much larger aquariums where its tankmates were as large, peaceful, and also somewhat slow moving. All environments had lots of open swimming space and somewhat dim lighting, as these fish are mostly nocturnal creatures.

Besides P. volitans, I have also kept P. antennata, P. radiate, and P. russelli, and also Dendrochirus biocellatus and D. zebra. As for P. antennata, it is usually called the Antennata Lionfish, Ragged-finned Lionfish or Spotfin Lionfish. It hails from East Africa to the Marquesas and Mangareva Islands north to southern Japan and south to the Great Barrier Reef. In the wild it hides mostly during daytime in caves and hunts crabs and shrimp at night. It’s about half the size of P. volitans and more shy, hiding under overhangs or spending much of its time in caves during the day. As long as tankmates were of not eatable size, they had nothing to fear. But when I placed a pair of damselfish in the aquarium, they soon disappeared. Probably a midnight snack. I also found it very fond of the small grass shrimp and crabs that I occasionally brought back from collecting trips in Mexico. Except for its propensity to hide a lot, its care was no different than P. volitans, and because of its smaller size could be maintained in tanks as small as 30 gallons. Nevertheless, my three specimens were all maintained in a 120 gallon system, giving me more space for providing many caves and ledges, which they liked to hover under during much of the day.

I should note that we traveled to Mexico waters frequently, as we live close to the border. And since I always brought back fresh live food for my lions, they often got spoiled (an understatement!) and some would holdout by refusing to take prepared foodstuffs while hoping to see ‘live’ food enter the water. There was one time I remember feeling sorry for them and purchased a bunch of inexpensive damselfish to keep them happy! I thought I saw ‘smiles’ on their faces! I even went as far as setting up a small outside tank where I tried to keep a ready supply of live fish and crabs from Mexico waters. That worked pretty good, as the outside temperatures here in Tucson Arizona are in line where I collect, and this outside tank received the water from my inside tank water changes.

As for P. radiata, it’s not seen too often and I had only one of these, which at one time was in the same tank with my three P. antennata. It’s generally called the Clearfin Lionfish or Radiata Lionfish and is a little larger than P. antennata. In fact it looked quite similar to P. antennata, except it did not have the colorful webbing/membrane on the pectoral fins. It hails from East Africa to Papua New Guinea north to Sri Lanka and south to South Africa, then west to Australia. It generally hides in caves during the day and hunts at night where its favorite natural food is crabs. Its disposition and care was no different than what was given P. antennata and got along peacefully with its ‘larger’ neighbors.

One of the easiest lions I’ve ever kept was P. russelli, which hails from the Indo-West Pacific Ocean. Its known by many names, such as Large Tail Turkeyfish, Soldier Lionfish, Russell’s Lionfish, Plaintail Lionfish, Red Volitans Lionfish, and Military Lionfish. In the wild it inhabits muddy estuaries and coastal reefs where sand or mud collects. Its what could be called a medium sized lionfish, as it gets about 11 inches (22 cm) and is one of the easiest lions to get feeding. The one specimen I kept was maintained in a 75 gallon aquarium that had some live rock and quite a few mushroom corals. It was not fussy about water quality, and rarely ever hid in the aquarium caves. As for feeding, it took various kinds of marine fish flesh and/or defrosted shrimp. When live marine foods were available, it perked up and chased it until it was eaten.

One of the more interesting lions I ever kept was Dendrochirus biocellatus, or what is generally called the Fu Manchu Lionfish, Twinspot Lionfish or Ocellated Lionfish. It hails from the Mauritius to the Society Islands, north to Japan and south to Australia. In the wild it hangs near reef faces and often stays in caves during the day and hunts at night. It has what could be called large ‘whiskers’ or a mustache on its upper snout. This was the smallest, about 4 inches (10 cm) lionfish that I ever kept, and probably the most difficult to feed. It sure liked grass shrimp and crabs when available, which were usually infrequent treats at the timeframe I kept this species. It would sometimes go a week or more without showing interest in a nice fish flesh morsel waving in front of its nose. In fact, I occasionally bought some saltwater raised Mollies to keep this specimen going, and probably spent fifty times more than what the specimen originally cost just to keep it well fed and happy. I even brought low cost damsels and/or clownfish fry that could not be sold by a hobbyist who was breeding them and had too many for sale to local dealers. This fish was kept in a 60 gallon tank that was somewhat dimly lit and had the same type caves and hiding places as all my other lionfish tanks. It also contained a lot mushrooms as they also liked the medium light and the higher nutrient content. All in all, it was a nice show tank but did not generate the same interest by its viewers as did Pterois volitans when seen.

As for D. zebra, another somewhat small Lionfish, as it only gets about 7 inches (18 cm), it was probably the second most popular lionfish that I ever kept. It hails from South Africa and the Red Sea to Samoa, and north to southern Japan and south to Lord Howe Island. And by popular, I mean the response from those who came to my home to see my aquariums. It is generally called the Zebra or Dwarf Lionfish and has extremely nice pectoral fins with its webbing/membranes extending all the way out to its tips. In the wild it generally occurs in lagoons and hangs out near coral rubble and sponges where it likes to hunt shrimp at night. This also was kept in a 60 gallon tank, but could be maintained in something as small as a 30 gallon tank. Feeding requirements were not much different than the other species mentioned above and was also maintained in a moderately lighted tank with a few hiding places.

When it comes to selecting a lionfish, be sure its eyes are clear, looks alert, fins are intact, and is breathing normally. And even though it is highly disease resistant, be sure it has no parasite spots on any of its fins or body. Be sure it will be housed in an environment that is conducive to its needs, i.e., sufficient hiding places, a moderately lit environment, and no tankmates that will attack its fins. And even though it’s a fish that doesn’t need to be fed daily, it does require two or three meals per week of the proper foodstuffs as mentioned above. Keep in mind it will eat anything alive and moving that it can fit into its mouth, so don’t house them with expensive shrimp or small fish, as they will sooner or later become a meal. And never forget about their venomous fins.

And I should add that I never lost a lionfish from disease or improper diet. They were always either given to other hobbyists or went back to the shop where purchased because I was either moving or had plans for another type aquarium environment. All in all, they are one of the most beautiful, interesting, attention getters, and fairly easy species marine aquarists can maintain.

References and recommended sources:

Kuiter, Rudie H. 1993. Coastal Fishes of South-Eastern Australia. University of Hawaii Press, Honolulu, Hawaii.

Debelius, Helmut & Kuiter, Rudie H. 1994. Southeast Asia Tropical Fish Guide. Tetra-Press, Melle, Germany.

Fenner, Bob. 1998. The Conscientious Marine Aquarist. Microcosm, Shelburne, VT.

Michael, Scott W. 1998. Reef Fishes, Vol. 1., Microcosm, Shelburne, VT.

Michael, Scott W. 1999. Marine Fishes, A PocketExpert Guide, Microcosm, Shelburne, VT.

Lions in My Aquariums

Authored by: Bob Goemans