Freshwater Puffer Fish are extremely interactive and interesting fish. Although not the easiest type of fish to keep, puffers are unlike an other species in the hobby.
These fish are gorgeous and personable and make great “water puppy” pets!
This complete guide will teach you everything you need to know about choosing, keeping, and caring for freshwater puffers.
About Freshwater Puffer Fish
The term “freshwater pufferfish” refers to many different species.
Some of these require freshwater forever while others need to be transitioned to brackish as they go. Pufferfish come in a wide variety, including fully brackish and marine.
This group of fish is extremely diverse, so we will delve into the individual care of several species in the “Common Species” section.
Most pufferfish are wild caught, so internal parasites are a common malady, and then tend to be extremely sensitive to nitrogenous compounds. However, the similarities between all species does not go much further than this.
The general rule for keeping freshwater pufferfish is to keep them alone. They are extremely aggressive fish, and even the pea puffer, which only grows to an inch long, will kill fish larger than itself.
They are equipped with a sharp beak to bite through the hard shell of mollusks, so they are capable of inflicting extreme damage on tank mates.
Some of the pufferfish we will discuss can be kept with others of their own kind, but you should always have a backup plan if you try to mix other fish with your puffer(s).
Freshwater pufferfish come from all over the world, but they tend to hail from very warm water. Excessive foliage is also common in their natural habitat, as are mollusks.
Without the essential mollusks, their beaks would grow and grow and grow until the upper half locked with the lower half, and the puffer would starve.
Freshwater Puffer Fish Species
Here we will discuss five common freshwater pufferfish species and how to care for them.
The pea puffer is unlike the other pufferfish in that you can find captive bred specimens.
The captive bred ones are hardier than the wild caught ones, aren’t prone to internal parasites, and live longer than their compatriots.
Another reason to buy captive bred pea puffers is due to the severe reduction in natural populations caused by the aquarium trade.
In addition, they are more likely to thrive in your water, as captive fish experience more water changes than wild caught fish.
Males and females are differentiable by coloration. They are both very small and brown with darker brown splotches. The males have neon green/metallic wrinkles around their eyes that the females lack.
In addition, the males often have a dark stripe down the middle of their bellies.
When buying your fish, make sure the ones you get have full bellies without abnormal bulges. If any of the fish in their tank have sunken stomachs, treat for internal parasites with something like API General Cure or PraziPro.
Pea Puffers, and all wild caught fish, are prone to having internal parasites.
Pea Puffers can be housed in groups, unlike the other pufferfish.
That being said, they are extremely territorial, and you should provide at least 5 gallons for every pufferfish and heavily plant the tank.
BB Puffers do not coexist with other fish well and will wipe out a community tank. While they are only 1”, they have very sharp beaks and will decapitate and take chunks out of other fish.
They prefer horizontal space over vertical space because they establish territories based on horizontal space.
- Scientific Name: Carinotetraodon travancoricus
- Size: 1”
- pH: 6.5-7.5
- Temperature: 77-80°F
- Other Names: Dwarf puffer, Dwarf Indian Puffer, BB puffer, Pygmy Puffer
As far as food goes, pea puffers are the easiest to provide for.
They do not require mollusks as part of their diet, though feeding pest snails is popular. However, the puffers often just bite off the head of the snail rather than crushing the shells.
Their primary diet in captivity is often worms. The worms vary from California blackworms, bloodworms, white worms, and tubifex worms. Pufferfish do not go after pellets or dried food, so you will have to provide live food.
Some captive bred specimens will eat pellets, but most BB puffers will not.
These fish are capable of changing color and do require crustaceans in their diet. On aspect of their care that is unique from other fish is their need for substrate.
Congo, or Potato, pufferfish need at least three inches of a deep sand substrate.
Congo puffers are ambush predators and spend most of their time buried, with only their eyes and a small part of their body exposed.
They also change coloration to match the substrate and are quite adept at making these changes.
Community tanks are a no-no, as this ambush predator will kill anything that moves. The other fish won’t know what’s happening until it is too late.
In the wild, they primarily eat fish, so they will instinctually do the same in aquariums.
Their normal diet in aquariums tends to be based around shrimp and bloodworms.
Bloodworms are very fatty and should not be fed with every meal, and the shrimp should be large pieces from the grocery store, with the shell on.
They can also eat large ramshorn snails, Malaysian trumpet snails, pond snails, and other pest snails. Unlike the small pea puffer, they will bite right through the shell and shred it.
- Scientific Name: Tetraodon miurus
- Size: 3-6”
- pH: 6.5-7.5
- Temperature: 74-80F
Congo puffers should be kept in aquariums between 30 and 40 gallons, with a 40-breeder having perfect dimensions for them.
They should have some décor, such as driftwood, rocks, pebbles, and some vegetation, in order to help them feel secure.
Similar to other intelligent species, the Congo pufferfish have distinct personalities. Some keepers report their fish enjoying sitting in their hand and responding to training, while others get bitten by theirs.
Each Congo puffer is different, but all are a joy to keep.
Those who keep these fish tend to do so because of their alluring beauty and impressive size.
These are not for the average fish keeper, but they are for those who want to acquire monsters for their aquariums.
They must be housed in a 120 or 125 gallon minimum, but a larger tank may be necessary depending on how large the puffer grows.
If it reaches 18”, you will need a larger tank since the aforementioned tanks are only 18” wide, not giving enough room for them to turn.
In addition, their food is very expensive. Their teeth must either be manually ground down, which is extremely dangerous for both you and your puffer, or be ground down naturally with tough foods.
Fahaka pufferfish are commonly fed clams, crabs, crayfish, worms, shrimp, and other mollusks.
The shrimp, crabs, and clams can be sourced from grocery stores, but must be uncooked and unseasoned.
You can also use feeder crabs, crayfish, and snails. For the Fahaka pufferfish, they must eat different types of food at different stages in their lives due to the size difference.
For example, young Fahaka puffers should be fed ramshorn snails while large ones can eat mystery snails.
As for the worms, they often do not have interest in bloodworms, blackworms, or white worms once they get large, but they always love nightcrawlers.
Nightcrawlers, red wigglers, and earthworms are large and full of protein.
- Scientific Name: Tetraodon lineatus
- Size: 14-18”
- pH: 7.0-8.0
- Temperature: 76-80F
The eyespot pufferfish is also commonly referred to as the figure 8 pufferfish.
Both of these names come from the spots on the back of the pufferfish that resemble either two eyes or an 8.
Similar to the pea puffer, these are relatively small fish, often not surpassing three inches, but like the Fahaka pufferfish, they require live crustaceans in their diet to keep their teeth ground down.
There is a debate over whether or not these are a freshwater fish. Some argue that they live longer in brackish water while others state that freshwater keeps them healthier.
They are capable of existing in both types of water, but naturally come from freshwater.
Very few keepers have reported some success in keeping the eyespot puffer in a community tank.
There is always a great risk that the puffer will kill all the other fish, but some have been able to manage their aggressive nature.
Those that have had success have used fish such as mollies and tetras, which are relatively large, fast, schooling fish. This suggests that keeping similarly large and fast fish may work with your puffer.
They should be fed hard-bodied food every day, such as shrimp, clams, and other mollusks. These puffers often require live food, which is an issue in a community tank, as they may chase down their tankmates instead.
- Scientific Name: Tetraodon biocellatus
- Size: 3”
- pH: 6.5-7.5
- Temperature: 75-79F
While many sources say a 15-gallon tank is a good size, a 20 long should be considered the minimum.
These fish are relatively active and territorial, so they appreciate any extra space you can give them.
You should provide them with rocks, driftwood, plants, and caves as hiding areas. Since they are small fish, they are preyed upon in the wild and are much more comfortable having places to hide.
Red-eyed pufferfish have strikingly striped gray bodies with brilliant red eyes. The males and females display drastically different patterns, and the females often look more vibrant.
This is another species of small pufferfish, reaching only two or three inches.
These are fully freshwater without any surrounding debate. They are aggressive to their own kind and to every other fish, so they cannot be housed in a community aquarium.
If provided with enough space (20-long minimum), it is possible to keep a male/female pair.
They must be fed mollusks, shrimp, and snails to keep their beaks ground down. Since these will again be sourced from the grocery store (minus the snails), they will likely be frozen.
This is a benefit, as it makes them even harder to chew, so it will wear the beak down faster.
Since they are small, the aquatic snails must not be too large. Just as the pea puffer tends to bite the head instead of the shell, the red-eyed puffer will do the same to large snails.
They must eat smaller pest snails to keep their teeth down.
- Scientific Name: Carinotetraodon miurus
- Size: 2-3”
- pH: 6.0-8.0
- Temperature: 77-80F
A 20 gallon is a good starting size for these pufferfish, despite their small size. They can act very timid, so having a well planted/decorated large space means it is more likely that you will see them.
Just like the Fahaka, these pufferfish are not for the average aquarist. They get very large and eat a massive amount of shellfish, which, as we all know, is not cheap.
Mbu Pufferfish are very rare in the aquarium trade, and for good reason.
Most people do not have the means or funds to take care of a fish that can potentially reach almost three feet long, hence the name, “giant pufferfish”.
These guys will eventually need a custom aquarium built for them, and it is best to start them out in a massive tank.
While the potential for three feet is there, most scarcely get over two feet long. All Mbu pufferfish are wild caught as they are currently impossible to breed in aquariums.
This is likely due to the lack of space for multiple three-foot long fish and the inability to sex them.
These are unique because they can be housed with other fish, even at a massive size. One such example is Murphey, a Mbu Pufferfish at Aquarium Co-op, that is housed with guppies in a 360- gallon aquarium.
The Mbu puffers do have an issue with beak growth, so they need daily mollusks, shrimp, crayfish, and snails, just like other puffers.
Due to their large size, there is a benefit to feeding them food that is still frozen.
Tank size for this fish is a widely debated topic. Since it will likely have to be a custom aquarium, it is best to make it as long as wide as possible and make it relatively short, only two or so feet.
Since puffers prefer horizontal space over vertical space, a long and wide aquarium will better house your fish. It will also be much easier for you to clean.
Since pufferfish shred their prey, they make a huge mess that you will have to clean frequently.
- Scientific Name: Tetraodon mbu
- Size: 24-30”
- pH: 6.0-8.0
- Temperature: 76-80F
Here are some key tips you should know before attempting to keep Pufferfish:
Each species has a slightly different requirement for water parameters, so we will discuss them with their respective species.
Even though they do have ideal parameters, it is more important to have stable parameters rather than “perfect” ones.
Is your water a little too hard? A little too soft? The pH a bit too low? It’s better to leave the parameters just how they are rather than fiddle with them.
In addition, acclimating your pufferfish is essential. For these sensitive little fellows, drip acclimation is by far the best option.
Float the bag they are in at the top of the tank, but at the same time, open it, remove some of the water, and begin dripping aquarium water in.
The easiest way to do this is to get a pitcher or similar container above the bag with airline tubing in it. Either tie a knot in the airline tubing or use a control valve so that it only drips out 1-3 drops per second into the bag.
This will slowly allow your pufferfish to adjust to their new water parameters and should take at least half an hour. Allow the water in the bag to double, then remove half, then let it double again.
You can then add your fish to its new home, but it is best to avoid adding any of the water from the store, as it may contain medications and pathogens.
All fish are sensitive to ammonia, nitrite, and nitrate, which is why it is essential to fully cycle your tank before adding fish.
Be sure that you have a complete understanding of the nitrogen cycle and testing kits before adding fish to your aquarium.
Most aquarium fish sold in pet stores will survive some levels of ammonia or nitrite for short periods of time (one to three days), but pufferfish will not. This is partly due to the fact that they are wild caught.
In the aquarium trade, fish will be exposed to nitrites and ammonia at some point or other.
Over time, the ones with the strongest resistance ended up breeding and create fish that are somewhat resistant to suffocation and burning caused by these nitrogen compounds.
However, ammonia, nitrite, and even nitrate are not often found in the wild. If you want, go and test local rivers, streams, lakes and ponds, and see what you can find.
Chances are, there won’t be any nitrogen compounds that you test.
Since pufferfish have not yet been exposed to lethal ammonia and nitrite, any trace amounts will kill them very quickly. They are especially sensitive to nitrites, but fully cycled tanks should never have nitrites or ammonia.
However, most fish can handle 20-40ppm nitrates, but with pufferfish, it is best to keep them as low as possible, such as 10ppm or less.
With the exception of the pea puffer, all of these fish need to eat shelled creatures very regularly.
They also need a widely varied diet, so you can feed anything from shrimp to clams to freshwater snails.
Shrimp and other shellfish can be acquired from the local grocery store, but they cannot have any sort of seasoning and should be raw.
If they are cooked, they are often cooked in certain oils or other seasonings that may not be listed and could harm your fish.
Pea puffers are commonly fed aquarium “pest” snails such as ramshorns, Malaysian trumpet snails, pond snails, and bladder snails.
They cannot subsist off only snails, but they can be a staple part of their diet. If you are primarily feeding snails, you should aim for 2-4 a day.
Worms are also an essential part of a pea puffer’s diet and are a good supplement for other pufferfish as well.
The worms should be live and range from California blackworms to tubifex to bloodworms and white worms.
Setting up a Pufferfish Tank
Interesting in keeping pufferfish? Here are some things you will need to consider:
Choosing a Substrate
Most of these pufferfish will prefer a sand substrate, which is what they would find in the wild. The addition of rocks and pebbles can help them feel more secure, especially for the Congo puffer, which may try and replicate the color of a rock.
Adding Live Plants
Since pufferfish are carnivorous, they do not prey on plants, and therefore make a great inhabitant of a planted tank. Most of them also feel much more secure in a planted tank, especially the small ones like pea puffers.
Here is a list of undemanding, easy aquarium plants that will draw out your puffer’s personality even more:
- Anacharis (Brazilian Water Weed)
- Scarlet Temple
- Banana Plants
- Red Root Floaters
- Java Fern
- Java Moss
- Christmas Moss
- Dwarf Sag
- Amazon Sword
Pea puffers absolutely adore plants, and some consider a planted tank essential for them. Plants also help remove nitrogenous waste, and since puffers are so messy and yet so sensitive, they can really help you in your battle against nitrates.
Pufferfish will die if there is even the slightest amount of ammonia or nitrite. These are not present in fully cycled aquariums, and to make sure you get it right, we will break down what cycling is.
Once you add an ammonia source, bacteria will begin to convert it to nitrite then nitrate, but this process takes around a month.
You must dose ammonia, if you are using pure ammonia, at a rate of 4ppm until nitrites appear, then dose at 2ppm.
You can also cycle the tank using other methods, but the ammonia method is the most successful. It is cruel to use fish to cycle the tank, as they suffer irreversible damage.
You could also throw in a piece of shrimp or fish to cycle it, but this method stinks, literally.
Even though you have to wait, you can go ahead and set up your tank with plants, rocks, and driftwood!
This is your chance to get it perfect before you add your fish because, trust me, it is much more difficult to rearrange your tank once it has fish.
In addition, the plants will carry in some bacteria that help convert ammonia to nitrite to nitrate, so it can even help speed up your cycle.
At the very least, they will help keep your tank stable after the cycling is done.
What’s better than a super happy and personable pet pufferfish? Baby pufferfish!
Which Pufferfish Species Can You Breed?
Unfortunately, most of these species have never been bred in captivity. Those that have are still few and far between, and the process is not well documented.
The pea puffer, figure 8, red-eyed pufferfish have been bred in captivity, though success is limited.
All these pufferfish are egg layers, so having either a spawning mat or spawning surface is necessary. Some breed in group tanks, while others need other tanks to spawn in.
Since they are already being fed high protein diets, conditioning is not necessary.
Since pea puffers can be housed together and should be kept in densely planted tanks, spawning may occur naturally. The male tends to lead the female to an area he deems secure, then they spawn there.
The area is normally a plant or group of plants. However, the babies may soon become food for any other puffers in the tank, including the parents.
You can either attempt to spawn them in a separate tank, remove the plants with the eggs, or remove the adult puffers.
Young pea puffers are incredibly small, and often too small to eat baby brine shrimp. You should begin by feeding them infusoria, copepods, young daphnia, microworms, and vinegar eels.
It should not take more than a few days for them to be able to eat baby brine shrimp.
As they grow, you should begin putting baby ramshorns in with the babies to start them on some kind of hard food.
Baby ramshorns also hatch out at extremely small sizes, so if you are able to transfer some egg sacks, they would help the babies immensely.
Figure 8 Puffers
Very little is known about breeding figure 8 puffers, but some claim that they must be bred in brackish water.
There are some reports of the male exhibiting parental care to the eggs and fry for about a week.
The babies will likely need live food similar to the pea puffers and should be transitioned to baby brine shrimp as soon as possible.
After baby brine, worms (as white worms, blackworms, tubifex, and bloodworms), daphnia, and snails should be added to the diet.
Red- Eyed Puffers
Similar to the other babies, baby red-eyed puffers cannot be fed brine shrimp outright. They can eat the same recommended food as the others.
The red-eyed pufferfish is known to have an elaborate courtship dance, during which the male tries to entice the female.
If he succeeds, she will release eggs over plants or a spawning mop which the male will then fertilize.
Just like the Figure 8 pufferfish, the male red-eyed pufferfish will display parental care for the eggs.
The male will fan the eggs and guard them until they hatch to protect them from fungus and predators alike.