The Freshwater Lionfish Batrachomoeus trispinosus is a most interesting fish that can be kept in the brackish water aquarium. These unusual fish are found in the muddy bottoms of mangrove estuaries and coastal waters. It is actually more of a marine fish, but because in nature it spends a good deal of time where salt waters are mixed with fresh, it is more adaptable to lower salinity levels than other marine animals.
Its common name in Australia is the Three-spined Frogfish. No one is quite sure how it received the common name of Freshwater Lionfish. They are not related to the saltwater Lionfish, sub-family Pteroinae, and fortunately they are not venomous like those saltwater Lionfish. Probably someone with an overactive imagination couldn’t pronounce "Batrachomoeus trispinosus" and needed to call them something! They are members of the Batrachomoeus genus, which are non-venomous Toadfish.
The Freshwater Lionfish is truly an oddball fish, and rather grumpy. The names of Toadfish, Frogfish and even Stonefish give a good impression of what this fish looks and acts like. It sits very still and looks much like a camouflaged brown lump or stone, thus the name Stonefish. The broad head and large mouth are very frog-like. It also feeds very much like a frog or toad would, waiting patiently until its food comes within range and then gulping it down quickly.
The members of the Toadfish family, Batrachoididae, received their name because most of them can make a croaking sound when they are pestered or the males are courting females. It is unlikely that your pet will make this sound but you never know. Some aquarists have reported their fish grunting loudly when fellow inhabitants swim by, giving their tank mates quite a scare and making them race out of the area.
The Freshwater Lionfish gets to be quite large, reaching almost 12 inches (30 cm) in length. But despite its large size, it really doesn't need a large tank because it is quite still most of the time. It is camouflaged to blend in with its surroundings. It is peaceful, but it is a predator. Choose tank mates that are too large to fit into its cavernous mouth.
The Freshwater Lionfish Batrachomoeus trispinosus was described by Günther in 1861.They are a common species found throughout the Indo-West Pacific; northwestern Australia, Thailand, Indonesia, Papua New Guinea, the Arafura Sea, and the Mekong delta. The species is not listed on the IUCN Red List.
Most species seen in the aquarium fish trade are exported from Thailand. Its common name in Australia is the Three-spined Frogfish. Other common names these fish are known by include Freshwater Stonefish, Freshwater Frogfish, Freshwater Toadfish, Threespine Toadfish, Broadbent's Frogfish, Estuarine frogfish, Threespine Frogfish, and Toadfish.
These toadfish inhabit trawling areas of coastal waters and the muddy bottoms of mangrove estuaries, as well as reefs. In the wild the diet of toadfish is quite varied, including such items fish, crabs, shrimp, octopuses, bivalves, snails, sand dollars, urchins, and polychaete worms.
Scientific Name: Batrachomoeus trispinosus
Social Grouping: Solitary
IUCN Red List: NE - Not Evaluated or not listed
The Freshwater Lionfish is quite large, reaching almost 12 inches (30 cm) in length. The head is about a third of its length, and it has a big mouth. There are spines in its skin. These can cause pain if they are brushed against with your hand. Though this isn't really a threat, if a person is prone to allergic reactions they should be cautious. The coloring is a dark mottling of browns allowing it to blend into the environment. It sits motionless, looking much like a camouflaged brown lump, or stone, thus the name Freshwater Stonefish.
Size of fish - inches: 11.8 inches (29.97 cm)
Lifespan: 20 years
Fish Keeping Difficulty
They are actually pretty easy to care for and will be comfortable in a variety of water conditions. Yet although they are called Freshwater Lionfish, they will not be long lived in strictly fresh water. The really need to be kept in either a brackish water aquarium, or even a saltwater environment. These fish live in freshwater at low tide, that turns to brackish and then at high tide, to saltwater. Feeding can be difficult as these fish prefer live foods that swim by them. They won't take flake or pellet foods, and they need to learn to eat dead/ frozen foods. This takes patience, but can usually be accomplished with a feeding stick.
Aquarium Hardiness: Moderately hardy
Aquarist Experience Level: Advanced
Foods and Feeding
The Freshwater Lionfish are carnivores, a predator. In the wild they feed on live crustaceans and fish. In the aquarium feed a variety of foods including bloodworms, earthworms, river shrimp and crayfish. Some fish foods that you can offer include tilapia, rainbow trout, pollack, and cockles. Prawns and shrimp can be used in the short term to get your fish eating.
This fish relies on camouflage and stealth to get a meal so if their prey doesn't swim directly in front of them, they may not get enough to eat. Using a feeding stick, aquarium tongs, or forceps to hold foods in front of their mouth is a good way to make sure that it is getting enough to eat. It may take awhile to get one to feed so be patient. Be careful not to overfeed these rather sedentary fish. Provide just enough so that the belly fills out slightly but doesn't look inflated.
Some varieties of live fish and saltwater invertebrates are not recommended, at least not for the long term. These include goldfish and guppies, as well as mussels, shrimps, prawns and at least some types of squid. With Goldfish and guppies there is the risk of introducing parasites. Also, these fish and these invertebrates are rich in an enzyme called thiaminase. Thiaminase metabolizes or breaks down vitamin B1 which over the long term can cause severe health problems. The fish listed above are thiaminase-free foods.
Diet Type: Carnivore
Flake Food: No
Tablet / Pellet: No
Live foods (fishes, shrimps, worms): Most of Diet
Meaty Food: All of Diet
Feeding Frequency: Weekly
This species is best suited for a saltwater or brackish water tank. It can only be kept in fresh water for a short time, but it cannot be permanently maintained in freshwater and live. Acclimate them to a brackish tank slowly, over a period of about a week. They must have a minimum specific gravity of at least 1.005, but a heavy brackish water of 2.5 % to 3% salinity density (specific gravity 1.020-1.024) is suggested for the long term.
Provide weekly partial water changes as needed, generally about 25 - 50%. Water changes can be quite variable, depending on salinity, tank size, and stocking density (bio-load). For example, a saltwater aquarium generally needs about twice as much water changed out as a freshwater aquarium.
Water Changes: Weekly - Do water changes as needed, generally about 25 - 50% weekly.
The Freshwater Lionfish needs a brackish water or saltwater environment. It cannot be maintained in freshwater as it will not live for long. They must have a minimum specific gravity of at least 1.005, and up to 1.024. Provide a minimum tank size of 40 gallons or more for a juvenile. Larger fish will need much more room with 100 gallons or more being best.
This species will spend all of its time on the bottom of the tank. A gravel substrate along with rock caves to provide some hiding cover is recommended to keep it in good condition. You can also provide some areas of dense vegetation. They like to be able to camouflage themselves as much as possible to feel safe. A good canister filter that makes a moderate current will be appreciated by this fish.
Minimum Tank Size: 40 gal (151 L) - Adult Three-spined Frogfish will need 100 gallons or more.
Suitable for Nano Tank: No
Substrate Type: Large Gravel
Lighting Needs: Low - subdued lighting
Temperature: 72.0 to 82.0° F (22.2 to 27.8° C)
Range ph: 7.8-8.5
Hardness Range: 7 - 10 dGH
Water Movement: Moderate
Water Region: Bottom - The Freshwater Lionfish will spend all of it time on the bottom.
Choose tank mates that are too large to fit into its cavernous mouth. This fish is not at all aggressive but since it is a predator with a very large mouth, considerable care is needed when choosing tank mates. They will stay secluded under cover during the day, though may come out at night. As they become comfortable and learn their feeding regime, they may start to venture out when the lights are on.
Venomous: No - Though not venomous, there are spines in its skin that can cause pain if brushed against with your hand.
Temperament: Peaceful - Peaceful, but a predator that will eat any fish that fits in its mouth.
Same species - conspecifics: Yes
Peaceful fish (): Monitor - Must be large enough to not be considered food.
Semi-Aggressive (): Monitor
Aggressive (): Monitor
Large Semi-Aggressive (): Monitor
Large Aggressive, Predatory (): Monitor
Slow Swimmers & Eaters (): Monitor - Must be large enough to not be considered food.
Shrimps, Crabs, Snails: Threat - is aggressive - Crustaceans are part of its natural diet.
Sex: Sexual differences
Breeding / Reproduction
The Freshwater Lionfish has not been bred in an aquarium.
Ease of Breeding: Unknown
As with most fish the Freshwater lionfish are prone to skin flukes, parasitic infestations (protozoa, worms, etc.), ichthyobodo infection, parasitic infestations (protozoa, worms, etc.), bacterial infections (general), and bacterial disease. Anything you add to your tank has the possibility of bringing disease to your tank. Not only other fish but plants, substrate, and decorations can harbor bacteria. Take great care and make sure to properly clean or quarantine anything that you add to an established tank so not to upset the balance.
These fish are hardy and disease is not usually a problem in a well maintained aquarium. That being said there is no guarantee that you won't have to deal with health problems or disease. Because these fish eat live food, disease can be passed to them from their foods. Make sure to quarantine live food before feeding.
A good thing about the Freshwater Lionfish is that due to their resilience, an outbreak of disease can often be limited to just one or a few fishes if you deal with it at an early stage. When keeping more sensitive types of fish, it is common for all fishes to be infected even before the first warning signs can be noticed. The best way to proactively prevent disease is to give your fish the proper environment and give them a well balanced diet. The closer to their natural habitat the less stress the fish will have, making them healthier and happy. A stressed fish is more likely to acquire disease..
Knowing the signs of illness, and catching and treating them early makes a huge difference. It is recommended to read up on the common tank diseases. For information about freshwater fish diseases and illnesses, see Aquarium Fish Diseases and Treatments.
The Freshwater Lionfish is commonly available. They are also called the Three-spined Frogfish, Freshwater Toadfish, Freshwater Frogfish, and Freshwater Stonefish.
Christopher - 2015-06-19 Okay, so I am soon to be buying a new 55 gallon tank and beginning my brackish water adventure. I used to own a Dragon Fish named Guru who was sold to me as a freshwater fish (Most pet stores will sell them as such which is Horse Crap!) I loved the Dragon Fish, easy to take care of (even when he got sick with skin disease all I had to do was put him in a cup with a squirt of anti-fungal and leave him for 6 minutes and he was good as gold) He lived for the whole 5 years I had him until I was forced to give him up to my brothers dad (didn't have enough space to re-home him, plus brothers dad loved it when Guru would send his Blue FW Lobster flying across the fish tank). I am going to get another Dragon Fish, but am wondering if a Stonefish will be a good tank mate. Also, can anyone give me any names of brackish water algae/tank cleaning crews (i.e fish), When Guru was a FW fish, he tended to get along very well with a Snowflake eel, Cory Catfish, and Pleco (Now that I know Dragon Fish are Brackish, I'm looking for tank mates that aren't Aggressive.)
Clarice Brough - 2015-06-20 That's really exciting! I only had one of these fish, and for a short period of time as I re-homed him. But brackish is so cool, and so is the Freshwater Lionfish. I've got a couple of juvenile Archer's that will be brackish as adults (in a 150 gallon show tank), so am looking forward to the experience too.
By the way, the Snowflake Eel is also not a freshwater fish, but like so many brackish and marine species, they hatch out in freshwater rivers and are collected when young. As young specimens they are then acquired by stores and so are often still in freshwater, but will need to be aclimated to a salt environment as they age.
Not sure if a stonefish is a good idea or not, they are very venomous, so kind of risky for the keeper:) Wishing you the best on your fish and brackish aquarium!
Andrea - 2014-08-27 I have one stonefish which I have had for about 6 months. I have kept him in freshwater and have not seen him eat, but he must be eating because he is still alive. I have him with other fish... red tailed catfish, banjo, and spotted raphael. I feed him goldfish
Jess - 2014-12-10 Is this fish still available??
michael - 2015-01-07 lionfish are nocturnal and they hunt at night so if you have patience turn off the light and sit and watch him and you'll see him eat if you feed them live feed feeders
Ricky Garman - 2012-04-07 My freshwater lionfish laid eggs all over her aquarium. Now I hear they can't be breed in an aquarium but I would like to try. How do I tell male and females? any info. would help.
Clarice Brough - 2012-05-06 Wow, how cool is that! Not much known about how they breed. That's probably because being brackish fish from estuaries... replicating that environment has been almost impossible. Would love to hear what happens with your eggs!
william hale - 2010-06-09 Can you keep freshwater lionfish with freshwater stingrays?
Anonymous - 2012-01-15 Neither of these fish are aggressive... but they are both protein eaters with different behaviors and habitat needs. You would need a tank that is large enough to accomodate both. Both are fairly dormant except when feeding. The stingray needs a large flat sandy surface and gets active while feeding. The while the lionfish needs rockwork to quietly hide and lay in wait for prey. The lionfish would not be comfortable with a big ray rustling around feeding while its trying to be secretive. So the habitat would need to fit both lifestyles.