Most puffers are not freshwater fish, and one on our source’s own freshwater list is brackish
Freshwater puffer fish is a shop label rather than a group, and the family it comes from lives mostly in the sea. Under this one label our sources put a fish that lives in five gallons and a fish that needs five hundred.
Wikipedia gives the proportion: most pufferfish species live in marine or brackish waters, but several tropical genera, comprising about 35 species, spend their entire lifecycles in fresh water. It names where they are, and it is three places rather than one: South America, with Colomesus asellus and Colomesus tocantinensis; Africa, with six Tetraodon species; and Southeast Asia.
That matters at the shop counter because the label does not distinguish. Aquarium Store Depot publishes a list of thirteen it treats as freshwater, and then says of one of them, the green spotted puffer, that adults need specific gravity around 1.005 to 1.010. That is brackish water. A fish sold on a freshwater list that needs salt in the tank is the single most expensive mistake available under this heading.
The other thing Wikipedia carries that no aquarium source we hold does is the toxin. The majority of pufferfish species are toxic, with some among the most venomous vertebrates in the world, and the tetrodotoxin sits primarily in the ovaries and liver, although smaller amounts exist in the intestines and skin. None of our three aquarium sources mentions it once.
What this guide is
- The question
- Three thousand six hundred searches a month for a phrase that covers at least thirteen species, one of which is not a freshwater fish.
- Why it is filed here
- Under stocking, because the tank figure inside a single source runs from 5 gallons to 500, and 500 would be the second largest volume on this site.
- The record behind it
- Our pea puffer record, the only puffer written here, and the smallest fish on every list we cite.
The thirteen, and a factor of one hundred between the ends of one list
Aquarium Store Depot is the only source we hold that publishes a full set of figures for every species it names. This is that list, unaltered, sorted by the tank it asks for. The first row and the last row are separated by a factor of one hundred.
| Species | Tank | Adult size | Temperature | pH |
|---|---|---|---|---|
| Pea puffer | 5 gal | 1 in | 72 to 82 °F | 6.8 to 8.0 |
| Imitator puffer | 5 gal | 1 in | 76 to 82 °F | 6.8 to 7.5 |
| Red-tailed dwarf puffer | 15 gal | 1.5 to 2 in | 68 to 82 °F | 6.0 to 7.5 |
| Crested puffer | 15 gal | 2 in | 75 to 82 °F | 5.0 to 7.5 |
| Ocellated puffer | 20 gal | 6 in | 75 to 82 °F | 6.5 to 7.5 |
| Arrowhead puffer | 20 gal | 6 in | 72 to 79 °F | 6.5 to 7.5 |
| Golden puffer | 20 to 30 gal | 4 in | 74 to 80 °F | 6.0 to 7.8 |
| Hairy puffer | 30 gal | 5 in | 74 to 81 °F | 6.5 to 7.5 |
| South American puffer | 30 gal | 3 to 4 in | 75 to 80 °F | 5.5 to 8.0 |
| Green spotted puffer | 30 gal | 6 in | 75 to 82 °F | 7.5 to 8.5, brackish |
| Spotted Congo puffer | 40 gal | 4 in | 78 to 81 °F | 6.5 to 7.5 |
| Fahaka puffer | 100 to 150 gal | up to 17 in | 75 to 79 °F | 6.5 to 7.5 |
| Mbu puffer | 500 gal | 20 to 30 in | 75 to 79 °F | 7.0 to 8.0 |
Read the tank column against this site and the top of it is off our scale. The mbu’s 500 gallons would be the second largest tank figure we publish, behind only our redtail catfish record at 2,700 and ahead of our clown loach record at 120. The fahaka’s 100 to 150 would also land second. Store Depot does not soften it: the mbu is not a fish for a home aquarium in any conventional sense.
The size column does the same thing. A fish of 20 to 30 inches would be the second largest animal on this site, behind our redtail catfish record at 47 to 55 inches and ahead of our common pleco record at 15 in a tank. Wikipedia agrees on the scale from the other direction: a few species such as the Mbu pufferfish can reach lengths greater than 50 cm, 20 in.
The bottom of the column is where our own record sits. Store Depot gives the pea puffer 5 gallons, 1 inch, 72 to 82 °F and pH 6.8 to 8.0, and our pea puffer record publishes 5 gallons, 1 inch, 74 to 82 °F and pH 6.8 to 8.0. Three of the four rows are identical and the fourth differs by two degrees at the floor, which is as close as two independently written care sheets get on this site.
What the list does not carry is a lifespan for any species, and neither does Store Depot elsewhere on the page. Aquarium Co-Op publishes one figure, for the Amazon puffer: up to 8 to 10 years and sometimes even longer. Our pea puffer record carries 2 to 6 years from its own sources. So a one inch puffer and a three inch puffer differ in published lifespan by a factor of about two, and thirteen of the fourteen species named across our sources have no published figure at all.
One species, three sources, and they disagree about its size, its tank and whether it can live with anything
All three of our aquarium sources cover Colomesus asellus. Two of them call it a different fish, because it is sold under two names, and none of the three agrees with either other on the figures that decide a purchase.
| Figure | Aquarium Co-Op | Aquarium Store Depot | Seriously Fish |
|---|---|---|---|
| Name used | Amazon puffer | South American puffer | Amazon puffer |
| Adult size | 3 in | 3 to 4 in | 128 mm SL, about 5 in |
| Tank | 30 gal, 55 better | 30 gal | 48 by 12 by 12 in base |
| Temperature | 72 to 82 °F | 75 to 80 °F | 68 to 79 °F |
| pH | 6.0 to 8.0 | 5.5 to 8.0 | 5.5 to 8.0 |
| Hardness | none | none | 2 to 15 dGH |
| Community | Nips slower, long-finned fish | Most community-compatible on the list | Unsuitable for the general community aquarium |
| Group | none | none | A group of 6 or more |
| Lifespan | 8 to 10 years, sometimes longer | none | none |
The size row is the one that changes the tank. Aquarium Co-Op says the fish only grows to 3 inches, 7.6 cm, long. Seriously Fish gives a maximum standard length of 128 mm, which is about five inches, and standard length stops at the base of the tail rather than the tip, so the whole fish is longer still. That is not a rounding difference. It is a two thirds increase in the length of the animal you are buying.
The tank row follows from it and lands in the same place from both ends. Co-Op recommends at least a 30-gallon aquarium, but 55 gallons would be even better. Seriously Fish requires a base of 120 by 30 by 30 cm, 48 by 12 by 12 in, or larger for long-term care, and a 48 inch base is a 55 gallon tank. So Co-Op’s optional upgrade is Seriously Fish’s floor, and the honest reading of the two together is that 30 gallons is the number a shop can sell and 55 is the number the fish reaches.
The community row is a flat contradiction and it cannot be split. Store Depot calls this species the most community-compatible species on this list. Seriously Fish says it is not aggressive as such but unsuitable for the general community aquarium, and best-maintained alone or in a larger set-up. Co-Op sits between them and gives the mechanism: the fish has a bit of attitude and sometimes can nip at slower, long-finned fish, and is prone to eating invertebrates like snails and shrimp.
Read together, all three are describing the same animal and grading it against different questions. Store Depot is ranking it inside a family where most members must live alone, and on that scale it is the best of thirteen. Seriously Fish is measuring it against a general community tank, and on that scale it fails. Most community-compatible puffer and suitable community fish are not the same claim, and the list ranking is the one a shopper will read.
Seriously Fish adds the row neither other source has, and it is the one that decides the tank twice over: the species naturally forms loose aggregations and can behave nervously in the absence of conspecifics. Ideally a group of 6 or more should be purchased. Six five inch fish is not a 30 gallon tank on anyone’s arithmetic.
The beak never stops growing, and the fix is a snail we hold a record for
This is the one thing every source we hold agrees on, and it is the reason a puffer is not a fish you can feed from a tub of flake. Store Depot states the anatomy: a puffer’s beak is made of fused teeth that grow continuously throughout its life, and without hard foods to grind against, the beak overgrows and the fish cannot eat.
Wikipedia gives the same structure from the taxonomy side. Pufferfish are most significantly characterized by their four beak-like teeth, which are used to break apart and consume small crustaceans. Seriously Fish describes the consequence as a maintenance job rather than a diet: offer regular meals of shelled invertebrates such as snails, crab legs, cockles, etc., in order to maintain them at a reasonable length.
Aquarium Co-Op is the blunt one about what happens if you skip it: their teeth may become so overgrown that they can no longer properly eat. A fish that starves with food in front of it is a failure of husbandry three months earlier, not of feeding today.
What the sources name as the grindstone is a live animal, and two of them name the same two species. Co-Op: you must grind them down by feeding all sorts of crunchy foods, such as bladder snails, ramshorn snails, and freeze-dried krill. Store Depot: live snails are the preferred food, alongside frozen bloodworms and brine shrimp.
One of those two snails has a record on this site, and this is the only page here where a record appears as food. Our ramshorn snail record exists because ramshorn snails arrive uninvited on plants and multiply, and it is written as a snail to manage. Under this heading it becomes the answer to the beak, which is a genuinely useful thing for a keeper who has both problems at once.
The other direction is worth naming too. This site holds four snail records, our ramshorn, nerite, rabbit and assassin snails, and a puffer refuses all four as tank mates for exactly the reason it accepts one as food. Three other records here also list snails in the diet row: our clown loach, dojo loach and assassin snail records. The difference is that for a puffer the snail is not a preference, it is dentistry.
Most of them have no tank mates, and thirteen of our records share the water anyway
Store Depot writes the general rule and does not hedge it: most puffers do not have tank mates. They are species-only fish. On the consequence of trying, it is blunter still: the puffer always wins that situation, and the community fish always pay for it.
For two species on its list it removes the option entirely. The hairy puffer: species-only. Not negotiable. The arrowhead puffer: species-only tank, no exceptions. The fahaka, at up to 17 inches: will live alone for its entire life. No tankmates. That is three of thirteen where the correct number of other fish is zero, published as a flat statement rather than a caution.
This is where a temperature grid stops being useful, and it is worth showing why. Thirteen records on this site publish a band that contains our pea puffer record’s 74 to 82 °F entirely, including our corydoras, ember tetra, chili rasbora, guppy and cherry shrimp records. Every one of those is a fish or a shrimp that a puffer is published to bite.
So the water agreeing is not the same as the fish agreeing, and on this family the gap between the two is as wide as it gets on this site. Our tank mates grid prints the overlap and the refusal separately for exactly this reason: a shared band is a fact about two rows, and a bitten fin is a fact about an animal.
The exception is the species in station 03, and even there the sources split. Store Depot ranks Colomesus asellus the most community-compatible of the thirteen; Seriously Fish calls it unsuitable for a general community aquarium and asks for six of its own kind instead. If you want a puffer with company, the company our sources agree on is more of the same puffer, and only for that one species.
One more line from Wikipedia belongs here, because it is the thing a keeper meets and no aquarium source we hold explains. The defense is to fill its extremely elastic stomach with water, or air when outside the water, until it is much larger and almost spherical in shape. The parenthesis is the important half: a puffer lifted out in a net can take in air rather than water.
The tank around the fish, and two of the three plants one source names have records here
Only one of our sources describes the setup rather than the animal, and the first thing it says is about the filter. Aquarium Store Depot: strong filtration is not optional. An oversized filter rated for double the tank volume is the right starting point, not the maximum. That is a consequence of the diet in station 04, because a fish fed whole snails and shelled invertebrates produces more waste than a fish fed flake.
On plants it is specific and it is honest about the damage. Live plants help water quality and add visual breaks in the tank. Large puffers are hard on plants, so stick with tough, fast-growing species: Java fern, anacharis, hornwort. So plants in a puffer tank are chosen for durability, not for looks, and the reason to want them is water quality plus sight lines between fish.
Two of those three plants have records on this site, and both agree with the water. Our java fern record runs 72 to 82 °F and our hornwort record 59 to 86, and both contain our pea puffer record’s 74 to 82 entirely. Anacharis has no record here yet. Java fern is also the plant our bristlenose pleco record names as pleco-safe, so it is turning into this site’s answer for a tank with a fish that chews.
Substrate appears once, for one species, and it is a requirement rather than a preference. The hairy puffer needs 2 to 3 inches, 5 to 7 cm, of fine substrate to bury into, which is the same species Store Depot marks species-only and not negotiable. An ambush predator that hides in sand needs the sand as much as it needs the tank.
What no source we hold discusses at all is worth naming, because on most fish these are standard sections. None of our sources covers sexing a puffer, and none covers breeding one in captivity. Store Depot publishes thirteen species profiles without a male or female anywhere in them; Aquarium Co-Op and Seriously Fish are silent too. On a family this popular that is a genuine hole in the published record rather than an omission on our part, and it is why those rows are empty here.
Nothing we hold covers lids either, which is the one gap a keeper is most likely to discover by accident. Every figure in station 02 is about the water and none is about what stops the fish leaving it.
Which freshwater puffer fish actually fits a normal tank
Sort the thirteen by the tank they ask for and the answer is short. Four of them fit in 20 gallons or less: the pea puffer and the imitator at 5 gallons, and the red-tailed dwarf and the crested at 15. Two more sit at 20, the ocellated and the arrowhead, and one of those two is species-only with no exceptions.
The pea puffer is the one this site has written, and it is the one our sources treat as the entry point. Store Depot lists it first, gives it 5 gallons, and calls the imitator essentially the pea puffer’s rarer cousin. Co-Op names it as the alternative to the Amazon puffer without publishing figures for it. Our own pea puffer record carries the nine rows in full, including the one thing Store Depot flags in a single word: temperament, aggressive.
Below 5 gallons there is nothing, and above 30 the list turns into fish that need a room rather than a stand. That leaves a real gap in the middle, and it is worth stating plainly rather than filling: of the thirteen species named, the number that are both truly freshwater and sized for a common 20 to 40 gallon tank is about six, and three of those Store Depot describes as rare or still rare in the hobby.
What we cannot tell you is which of them you will actually find. Store Depot says of the golden puffer that it is still rare in the hobby and of the imitator that it is the rarer cousin, and no source we hold publishes availability for any species. That is the gap between a list of thirteen and a shop with two tanks, and it is not a gap a care sheet can close.
Freshwater puffer fish questions, answered from the sources
Are freshwater puffer fish actually freshwater?
Some are and most of the family is not. Wikipedia: most pufferfish species live in marine or brackish waters, but several tropical genera, comprising about 35 species, spend their entire lifecycles in fresh water. It puts those in South America, Africa and Southeast Asia. The catch is at the shop: Aquarium Store Depot publishes a list of thirteen freshwater puffers and one of them, the green spotted puffer, needs specific gravity around 1.005 to 1.010, which is brackish water.
What is the smallest freshwater puffer fish?
The pea puffer at 1 inch, in 5 gallons, and the imitator puffer matches it on both figures. Aquarium Store Depot calls the imitator essentially the pea puffer’s rarer cousin. Our pea puffer record is the only puffer written on this site and publishes the same 5 gallons and 1 inch, with pH 6.8 to 8.0 identical to the source and temperature differing by two degrees at the floor.
What is the biggest freshwater puffer fish?
The mbu puffer, at 20 to 30 inches in a 500 gallon tank on Aquarium Store Depot, which says plainly it is not a fish for a home aquarium in any conventional sense. Wikipedia agrees on the scale: a few species such as the Mbu pufferfish can reach lengths greater than 50 cm, 20 in. For context, 500 gallons would be the second largest tank figure on this site, behind only our redtail catfish record at 2,700.
What size tank does a freshwater puffer fish need?
Anywhere from 5 gallons to 500, inside one source, which is why this guide is filed under stocking. Four of the thirteen species Aquarium Store Depot names fit in 20 gallons or less; the fahaka needs 100 to 150 and the mbu 500. There is no useful answer to this question without the species name, and that is the single most important thing the shop label leaves out.
How many freshwater puffers can share a tank?
For most species the answer is none, including none of their own kind. Aquarium Store Depot: most puffers do not have tank mates. They are species-only fish. The exception our sources name is Colomesus asellus, where Seriously Fish asks the opposite: the species naturally forms loose aggregations and can behave nervously in the absence of conspecifics. Ideally a group of 6 or more should be purchased.
Can freshwater puffer fish live with other fish?
Usually not, and our sources contradict each other on the one species where it might work. Aquarium Store Depot: most puffers are species-only, and the puffer always wins that situation, and the community fish always pay for it. For the hairy puffer it says species-only. Not negotiable; for the arrowhead, no exceptions; for the fahaka, no tankmates. On Colomesus asellus it calls the fish the most community-compatible on its list while Seriously Fish calls the same fish unsuitable for the general community aquarium.
Why do puffer fish need to eat snails?
Because the teeth never stop growing. Aquarium Store Depot: a puffer’s beak is made of fused teeth that grow continuously throughout its life, and without hard foods to grind against, the beak overgrows and the fish cannot eat. Aquarium Co-Op names the foods: bladder snails, ramshorn snails, and freeze-dried krill. Seriously Fish frames it as upkeep, offering shelled invertebrates in order to maintain them at a reasonable length. One of those snails has a record here, our ramshorn snail.
What happens if a puffer fish teeth get too long?
Aquarium Co-Op states the outcome: their teeth may become so overgrown that they can no longer properly eat. This is a slow failure rather than a sudden one, so a puffer that stops feeding is usually reporting a diet problem from months earlier. The prevention is hard-shelled food on a regular schedule, not a treatment applied once the beak is already overgrown.
Are freshwater puffer fish poisonous?
The family is, and none of the three aquarium sources we hold mentions it. Wikipedia does: the majority of pufferfish species are toxic, with some among the most venomous vertebrates in the world, with tetrodotoxin found primarily in the ovaries and liver, although smaller amounts exist in the intestines and skin. This record prints that because it is a fact about the animal, and notes that our keeping sources are silent on it.
Why do puffer fish puff up?
As a second line of defense, and Wikipedia gives the mechanism with a detail that matters in a fish room: the fish fills its extremely elastic stomach with water, or air when outside the water, until it is much larger and almost spherical in shape. The parenthesis is the practical half, because it means a puffer handled in the air can take in air rather than water. No aquarium source we hold discusses it.
What is the difference between an Amazon puffer and a South American puffer?
Nothing. They are the same species under two names. Aquarium Co-Op and Seriously Fish both call Colomesus asellus the Amazon puffer; Aquarium Store Depot calls it the South American puffer. Seriously Fish gives the binomial as Colomesus asellus Müller and Troschel, 1849, formerly Chelichthys asellus and Cheilichthys asellus. Anyone comparing two care sheets under the two names is comparing the same fish and will find they disagree.
How big does an Amazon puffer get?
Three inches or five, depending which source you read. Aquarium Co-Op says it only grows to 3 inches, 7.6 cm, long. Aquarium Store Depot says 3 to 4 inches. Seriously Fish gives a maximum standard length of 128 mm, about 5 inches, and standard length is measured to the base of the tail rather than the tip. The tank recommendation moves with it: 30 gallons on Co-Op against a 48 inch base on Seriously Fish, which is a 55 gallon tank.
How long do freshwater puffer fish live?
Only one figure exists across all our sources for the larger species. Aquarium Co-Op gives the Amazon puffer up to 8 to 10 years and sometimes even longer. Aquarium Store Depot publishes no lifespan for any of its thirteen, and Seriously Fish publishes none either. Our pea puffer record carries 2 to 6 years from its own sources, so the two ends of the family differ by roughly a factor of two.
What water parameters do freshwater puffer fish need?
Across the thirteen species Aquarium Store Depot names, temperature runs 68 to 82 °F and pH runs 5.0 to 8.5, which is nearly the whole usable range of a freshwater tank. Per species the bands are narrow: the mbu 75 to 79 and pH 7.0 to 8.0, the crested 75 to 82 and pH 5.0 to 7.5. The family figure is useless and the species figure is not, which is the same lesson as the tank row.
Are freshwater puffer fish good for beginners?
The small ones are keepable and none of them are forgiving. The pea puffer needs 5 gallons, which is beginner scale, but Aquarium Store Depot marks its temperament aggressive and every source requires live or hard-shelled food to keep the beak down. A puffer is a fish with a standing maintenance requirement that cannot be met from a tub of flake, and that is a different kind of difficulty from a hard water parameter.
Can you keep plants with freshwater puffer fish?
Yes, and one source names which ones. Aquarium Store Depot: live plants help water quality and add visual breaks in the tank. Large puffers are hard on plants, so stick with tough, fast-growing species: Java fern, anacharis, hornwort. Two of those three have records here and both contain the pea puffer band entirely: our java fern record at 72 to 82 °F and our hornwort record at 59 to 86. Anacharis is not written here yet.
What filter does a puffer fish tank need?
A bigger one than the tank size suggests. Aquarium Store Depot is the only source we hold that addresses it: strong filtration is not optional. An oversized filter rated for double the tank volume is the right starting point, not the maximum. That follows from the diet, because a fish fed whole snails and shelled invertebrates produces more waste than one fed prepared food.
How do you tell a male from a female puffer fish?
None of our sources says. Aquarium Store Depot publishes thirteen species profiles with no mention of sexing; Aquarium Co-Op and Seriously Fish do not address it either. This is a real hole in the published record rather than something omitted here, and it is the reason this guide carries no sexing section. If a source we trust publishes one, it will be added and named.
Can you breed freshwater puffer fish at home?
No source we hold explains how. Breeding and spawning are absent from all three aquarium sources, which is unusual for a group this popular. Seriously Fish notes that Colomesus asellus forms loose aggregations and asks for a group of six or more, but that is a stocking instruction rather than a breeding one. Where a fish this widely sold has no published spawning account across three keeping sources, the honest answer is that we cannot tell you, and this guide says so rather than filling the gap.
Which freshwater puffer fish are species-only?
Aquarium Store Depot names three outright: the hairy puffer, species-only. Not negotiable; the arrowhead puffer, species-only tank, no exceptions; and the fahaka puffer, which will live alone for its entire life. No tankmates. It also gives the general rule that most puffers do not have tank mates, so the safe assumption for any species it does not explicitly clear is a tank of one.