Freshwater Lionfish Care 101: Size, Lifespan, Tank Mates & Feeding

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The Freshwater Lionfish (Batrachomoeus trispinosus) is one of the most unique and interesting brackish water aquarium fish out there. 

This fish is predatory bottom-dwelling species that mainly spends its time on the bottom of the substrate, waiting to pounce on an unsuspecting meal.

Despite their Freshwater name, these fish are actually found in both marine and brackish habitats.

If you’re standing in your local fish store looking at this oddball fish and thinking about adding one to your collection, read on for everything you need to know about Freshwater Lionfish.

Species Summary

Three-spined toadfish (Batrachomoeus trispinosus)“Three-spined toadfish (Batrachomoeus trispinosus)” by wildsingapore is licensed under CC BY-NC-SA 2.0

The Freshwater Lionfish (Batrachomoeus trispinosus) is a toadfish from the Batrachoididae family. It’s an unusual fish that is known to cry like a baby. 

Native to the muddy bottoms of shallow mangrove estuaries, coral rubble, and along coastal waters in the Atlantic, Indian and Pacific oceans, the Freshwater Lionfish is actually a brackish – marine fish that can survive in fresh water for a short amount of time but will require a brackish and marine environment to thrive. 

The Freshwater Lionfish is called three-spined frogfish in Australia. Besides, it has many other common names, including Broadbent’s frogfish, Freshwater Stonefish, Freshwater Frogfish, Freshwater Toadfish, Threespine Toadfish, Estuarine frogfish, Threespine Frogfish, and Toadfish.

The Debate of Toadfish 

The common name Toadfish does create a bit of confusion and debate around the community. Toadfish is the common name for describing a wide range of species from several different families of fish, especially the entire family Batrachoididae and members from the Tetraodontidae family and Psychrolutidae family. 

These fish are commonly called “Toadfish” instead of “Frogfish” because the “Frogfish” common name is already taken by members of the Antennariidae family. 

According to FishBase: there are more than 18 recognized species called Toadfish as well.

Allenbatrachus grunniensMalaysia
Antennarius biocellatusUnited States
Antennarius hispidusMalaysia
Antennarius striatusMalaysia
Antennatus nummiferMalaysia
Barchatus cirrhosusUnited States
Batrachomoeus occidentalisMalaysia
Batrachomoeus trispinosusMalaysia
Daector reticulataUnited States
Halobatrachus didactylusSpain
Halobatrachus didactylusUnited Kingdom
Myliobatis aquilaUnited Kingdom
Porichthys porosissimusUruguay
Psychrolutes marcidusAustralia
Thalassophryne montevidensisUruguay
Torquigener pallimaculatusMalaysia
Torquigener tuberculiferusMalaysia
Triathalassothia argentinaUruguay

It is worth noting that most members of the order Batrachoidiformes are marine and predominantly found in brackish water. However, there are two species from its subfamily, the Thalassophryninae, which are found in freshwater.

SpeciesOriginAquarium Trade
Daector quadrizonatusAtrato River in ColombiaX
Thalassophryne amazonica (Prehistoric monster fish)mazon Rive

The Thalassophryne amazonica (Prehistoric monster fish) has been introduced to the aquarium trade for years and sometimes spawns in captivity.

So next time when an LFS worker tells you that their Toadfish can go in full freshwater, just check if it’s the Thalassophryne amazonica.


Although we have no clue where its common name of Freshwater Lionfish came from, as its name of Toadfish tells, the Freshwater Lionfish shares some physical characteristics with members of the Toadfish family. 

The Freshwater Lionfish are venomous. This fish has a wide, flattened scaleless body that’s covered in spines. Fortunately, unlike saltwater Lionfish, their spikes are not coated with venom and are drab in coloration.

However, it can be painful if you’re poked by their spines. Some may even bite if you handle the fish with your hand.

This species also has a super wide mouth, with eyes set high on its large head. The head is about a third of a Freshwater Lionfish’s total length. The lip is often camouflaged with skin flaps and fleshy barbels.

The body is dark brown with distinct light brown bars on the sides and discernible markings on its head. One of the defining characteristics of Batrachomoeus Trispinosus is a pit located behind its pectoral fin’s upper edge area. 

How Big Do Freshwater Lionfish Get?

These fish can grow to be quite large. The average size of a Freshwater Lionfish is 12 inches (30 cm) long when fully grown. When sold, these fish can be a third of their max size.

If you want to make sure these fish grow to their potential size, you’ll need to provide them with ideal habitat from day one.

Freshwater Lionfish Lifespan

The average Freshwater Lionfish lifespan is around 15 years with proper care. There have been reported specimens can live up to 20 years, but this is quite rare. 

Like most aquarium species, there are no guarantees with their life expectancy. Many factors can affect their lifespan in captivity, including water quality, diet, stress levels, and more. Of course, genetics and luck play a role as well.

Care & Tank Setup

Freshwater Lionfish (Batrachomoeus trispinosus) are quite bottom-dwellers in the home aquarium, but they are grumpy, well-camouflaged predators.

Because of their size, personality, and specific care requirements, this fish is best for seasoned fishkeepers with a bit of experience.

As we mentioned earlier, Freshwater Lionfish require at least lightly brackish-water habitats to survive and thrive in a complete saltwater environment.

Freshwater Lionfish Tank Size

When choosing a tank for your Freshwater Lionfish, it is important to remember that they can grow to be quite large. 

The recommended tank size for a single adult Freshwater Lionfish is a minimum of 100 gallons, while a juvenile at the typical purchase size will require a minimum tank size of 40 gallons.

For those who plan on creating a multi-species community tank, bigger is always better.

Water Parameters

In the wild, Freshwater Lionfish live in both salt and fresh water as the tide rises and falls. They can be found in freshwater at low tide. As the tide rises, the water turns brackish, and then at high tide, it becomes saltwater. This unique habitat requirement can make it challenging to keep Freshwater Lionfish in home aquariums. 

Usually, they stick to near-shore areas. However, they can be found in deep waters. Inhabiting muddy bottoms in estuaries, it’s best to mimic their natural habitat as much as you can in the aquarium.

  • Water temperature: 72.0 to 82.0° F (22.2 to 27.8° C)
  • pH levels: 7.8 to 8.5
  • Water hardness: 7 to 10 dGH
  • Specific gravity: 1.020 to 1.025

To make sure the readings stay in the Freshwater Lionfish sweet spot, we recommend getting yourself a quality aquarium test kit. It’s one of the most important tools every fish keeper needs.

  • Contains one (1) API SALTWATER MASTER TEST KIT 550-Test Saltwater Aquarium Water Test Kit, including 6...
  • Helps prevent invisible water problems that can be harmful to fish and cause fish loss
  • Accurately monitors 4 most vital water parameters levels in saltwater aquariums: high range pH, ammonia,...
  • Designed for use in saltwater aquariums
  • Use for weekly monitoring and when water or fish problems appear

Décor And Vegetation 

In their natural habit, Freshwater Lionfish will spend all of their time hiding amongst the rocks and substrate, emerging to ambush their prey. Therefore, a gravel substrate with plenty of caves, overhangs, and hiding spots is ideal.

You can also use live or artificial plants to create some areas of vegetation that provide additional security for your Freshwater Lionfish. Just make sure any plants you use can tolerate the brackish conditions.

These fish are more active at night; subdued lighting is recommended. You should also make sure that your filtration system can handle the high bio-load that these fish produce.

Freshwater Lionfish Diet

The Freshwater Lionfish is a carnivore and will consume just about any live food that can fit into its mouth. 

In the wild, their diet consists of smaller fish, crustaceans, and invertebrates. In the aquarium, they will accept a variety of live food, including bloodworms, earthworms, Mysis shrimp, krill, and crayfish.

It may take time to get them used to frozen food, but eventually, they will learn to accept it.

Like all Toadfishes, Freshwater Lionfish are sluggish fish that don’t swim much for hunting. Instead, their dietary habits are much like a frog or toad would.

They will perch on the substrate or amongst the vegetation, waiting for an unsuspecting fish or invertebrate to swim by. When their prey gets close enough, they will quickly dart out and snatch it up in their mouth.

To make sure your fish get enough food, a long feeder tube or aquarium tongs can be used to place the food in front of their hiding spot.

Weewooday 3 Pieces Axolotl Tank Accessories, Extra...
  • Aquarium feeding set: the package includes 1 piece coral feeder tube and 2 pieces straight and curved...
  • Reliable material: the coral spot feeder is made of quality acrylic and rubber material, which is safe...
  • Appropriate size: the size of coral feeder is approx. 13.77 inch/ 35 cm, long tube help you arrive at...
  • Wide applications: you can feed liquid phytoplankton to corals or other aquatic animals by using coral...
  • Warm tips: pleas ensure that the coral feeder tube is washed and cleaned before use; Turn off your...

You should feed your Freshwater Lionfish 2-3 times per day, only giving them as much food as they can consume in a few minutes.

Freshwater Lionfish Tank Mates

When it comes to Fresh Freshwater Lionfish tank mates, it is best to avoid any fish that are small enough to fit into their mouths. 

The best tank mates for a Freshwater Lionfish are other large, non-aggressive fish occupying higher tank parts.

Some of our possible Freshwater Lionfish tank mates;

  • Scat Fish
  • Mono Fish
  • Archerfish


Unfortunately, there is no reliable way to breed Freshwater Lionfish in the home aquarium.

Final Thoughts

Now that you know everything about Freshwater Lionfish care, it’s time to make the decision of whether or not these interesting fish are the right fit for your aquarium.

If you have the proper setup and are willing to provide them with the live food they need, then these fish can be a great addition to your tank.

Don’t hesitate to leave a comment if you have suggestions on ways we can improve this guide.

Happy fishkeeping!

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Jeff Colt

Jeff Colt

Hello, I'm Jeff- an aquarium enthusiast with over 25 years of experience caring for a wide array of tropical fish, including koi, goldfish bettas, cichlids and more! For me: Aquariums are like jello - there's always room for more!

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