The one record here that eats another one
Eight records on this site describe animals that can share water with something. This one describes an animal whose diet is one of the other records.
Seriously Fish states it plainly: the pea puffer needs small snails, with the shell on, regularly. Aquarium Co-Op says the same thing from the shopping end, naming live pest snails among what it eats. That is not a compatibility risk to weigh against a temperament note. It is the feeding instruction.
So this record carries the only outright refusal on the site that comes from a diet rather than from a warning. The nerite snail is an animal our records put at one to two years of life and a two gallon minimum. It is not a feeder, and a tank holding both is a tank where one of them is food.
Everything else about this fish follows from the same fact. A predator an inch long is still a predator, and both our sources spend more words on what it does to tank mates than on what water it wants.
Why this record was written now
- The gap
- Our tank mates page named the pea puffer as one of the five most searched pairings with no record behind it. It is the largest cluster on our list after the oscar, which does not fit the volumes this site covers.
- What it changes
- The pairing grid gains a refusal that is not the betta, and two cautions where our first two sources contradict each other outright.
- What it does not
- One field stays blank. The lifespan was blank too until two later sources filled it, and the two that were here first still do not state one, including the one that sells the fish.
Two sources, opposite answers
Every other record here disagrees with itself about a figure. This one disagrees about a decision, and the two positions are not reconcilable: one source names two animals this fish can live with, and the other names those same two animals as the ones to keep out.
| Question | Seriously Fish | Aquarium Co-Op |
|---|---|---|
| Community tank | Not usually recommended | Species only, expect it |
| Other fish | Nips fins of slow or long finned fish | Avoid any other fish |
| Algae eaters | Smaller loricariids, particularly Otocinclus | No algae eaters at all |
| Shrimp | Some freshwater shrimp | No clean up crew |
| Snails | Feed them, shell on, regularly | Live pest snails are food |
Which side we print, and why
The stricter one, because the cost of being wrong is not the same in both directions. If Aquarium Co-Op is right and you followed Seriously Fish, an otocinclus that already arrived starving loses its fins to a fish it cannot outswim. If Seriously Fish is right and you followed Aquarium Co-Op, you have a species tank that works.
That is an asymmetry rather than a judgment about which source is better, and it is the same reasoning our shrimp record uses about the betta.
What the grid shows instead
Our pairing grid marks the otocinclus and the cherry shrimp as a caution rather than a refusal, with the reason printed under it. A refusal would say something neither source says: that the pairing is out of the question. One of the two recommends it.
The nerite snail is the exception and it is marked never, because there the two sources agree completely. They just phrase it as a feeding instruction rather than as a warning.
An inch long, and harder water than you expect
Two fields on this record have every source stating the same figure, which happens almost nowhere else on this site. The rest are close enough that the overlap is the honest answer.
Size, and what it does not mean
One inch, 25 mm, and all four sources land on it, which no other field on this site manages. It is the second smallest animal on this site after the ember tetra, and the only one of the small ones that is a predator.
That combination is the reason people buy it for a tank it does not suit. A fish this size looks like a nano community animal and both our sources say it is not one.
Temperature: 74 to 82 °F
The overlap of the two ranges, which differ only at the floor: Seriously Fish starts at 72 and Aquarium Co-Op at 74. It shares the site wide band of 74 to 79 °F comfortably, which is worth knowing and changes nothing, because the animals in that band are the ones it should not be kept with.
Hardness: the widest range we hold
90 to 448 ppm, from Seriously Fish as 5 to 25 °H. It is the widest hardness range on this site by a distance, and the only floor above 89 ppm.
Put next to our guppy record it makes a point about soft water advice. The guppy asks for 143 ppm and up, the pea puffer for 90 and up, and the kuhli loach tops out at 143. Three records, and the two hard water animals overlap with the soft water one at a single point or not at all.
pH: 6.8 to 8.0
Seriously Fish. Aquarium Co-Op describes a wider tolerance of 6.5 to 8.4 and then names 7.2 to 7.5 as the ideal, which is the only place on this site where a source gives a target inside its own range. If you are setting one number, that is the one to set.
The full record
| Field | Recorded | Where it comes from |
|---|---|---|
| Minimum tank | 5 gal | Aquarium Co-Op, as five gallons for a single puffer and three more for each additional one. Seriously Fish asks for a base of 30 by 20 by 20 cm, about 12.6 liters, which is smaller than that, and two to three gallons per puffer in a group. We print the larger figure. |
| Temperature | 74 to 82 °F | The overlap of both: Seriously Fish gives 72 to 82 °F, Aquarium Co-Op gives 74 to 82. The floor is the only place they differ. Two more sources narrow it further: Puffer Fish Enthusiasts Worldwide gives 75 to 82 and Shrimpy Business 72 to 80, so all four overlap only between 75 and 80. |
| pH | 6.8 to 8.0 | Seriously Fish. Aquarium Co-Op describes a tolerance of 6.5 to 8.4 and names 7.2 to 7.5 as the ideal, which sits inside the range we print. |
| Hardness | 90 to 448 ppm | Seriously Fish, as 5 to 25 °H, converted here at about 17.9 ppm per degree. Aquarium Co-Op states no hardness figure. It is the widest hardness range on this site and the only floor above 89 ppm. Two later sources give a target inside that tolerance rather than the tolerance itself: Puffer Fish Enthusiasts Worldwide calls 7 to 12 dGH ideal and Shrimpy Business gives 8 to 16, so the overlap is 8 to 12 dGH, about 145 to 215 ppm. |
| Adult size | 1 in (25 mm) | Both sources agree, which happens on two fields of this record and almost nowhere else on the site. Seriously Fish gives it as maximum standard length. |
| Diet | Live and frozen, and snails with the shell on | Seriously Fish: all kinds of shellfish, worms and other live and frozen foods, and small snails with the shell on regularly. Both sources state that dried foods are usually refused. Aquarium Co-Op names frozen bloodworms and brine shrimp, and live pest snails or blackworms. The reason usually given for shell on snails is contested: Puffer Fish Enthusiasts Worldwide states that pea puffers, unlike larger puffers, do not have beaks that grow rapidly and do not require frequent hard shelled foods to keep their teeth worn down. The requirement stands on Seriously Fish; the dental explanation for it does not. |
| Water column | Mid water | Ours, and thinly supported: neither source states a water column. Aquarium Co-Op asks for a densely planted tank and Seriously Fish describes it nipping the fins of slow moving fish, which is behavior in open water rather than on the floor. On a species that both sources want kept alone, the layer decides less than usual. |
| Lifespan | 2 to 6 years | Shrimpy Business gives 2 to 6 years. Puffer Fish Enthusiasts Worldwide says most sources suggest an average of three years and that healthy, well maintained individuals often reach six or more. Neither Seriously Fish nor Aquarium Co-Op states a figure, which for a shop that sells the fish is worth noticing. |
| Growth rate | Not recorded yet | Not stated by either source. Seriously Fish gives a hatch time of about five days and a fry feeding order, which is a rearing schedule rather than a growth rate. |
The same nine fields for every animal on this site are in the A to Z index.
Where our sources disagree
This is the sharpest disagreement on the site, and it is not about a number. Both sources say this fish is difficult company. One of them then names two animals it can live with, and the other names those same two animals as the ones to keep out.
Seriously Fish
Not usually recommended for the community tank. Tends to nip the fins of slow moving or long finned fish and cannot compete with vigorous species. Compatible with smaller loricariids, particularly Otocinclus spp., and some freshwater shrimp.
Aquarium Co-Op
Buy them with the expectation of keeping them in a species only aquarium. Avoid any other fish, and no algae eaters or clean up crew.
What we record: we take the stricter position and print the other in full, because the cost of being wrong is not symmetrical. If Aquarium Co-Op is right and you followed Seriously Fish, an otocinclus that arrived starving gets its fins taken; if Seriously Fish is right and you followed Aquarium Co-Op, you have a species tank that works.
The pairing grid on our tank mates page marks both animals as a caution rather than a refusal for exactly this reason: one source recommends them.
It will not eat what you already own
Seriously Fish and Aquarium Co-Op both state that dried foods are usually refused, and neither of the later sources contradicts them. That is one sentence and it is most of the commitment this fish asks for, because the entire shelf of pellets and flakes that feeds every other animal on this site does not feed this one.
What it does take
Seriously Fish: all kinds of shellfish, worms and other live and frozen foods, and small snails with the shell on regularly. Aquarium Co-Op names frozen bloodworms and brine shrimp, live pest snails and blackworms, and mentions one dried food that has worked for them.
The phrase to hold on to is shell on. The snails are not only food, they are what the fish uses its beak for, and the source states them as a regular item rather than an occasional treat.
Which makes a pest snail colony a feature
This is the one place on this site where an animal nobody wants becomes useful. Bladder, ramshorn and trumpet snails breed in a tank, which our breeding page treats as the reason they need their own page, and a pea puffer turns that into a food supply.
Our records cannot tell you how to run that colony. No source we hold states how many snails a puffer needs or how fast a colony replaces them, so this record names the requirement and stops.
| Field | Seriously Fish | Aquarium Co-Op | Puffer Fish Enthusiasts | Shrimpy Business |
|---|---|---|---|---|
| Lifespan | not stated | not stated | 3 typical, 6+ well kept | 2 to 6 years |
| Adult size | 1 in (25 mm) | 1 in | about 25 mm | up to 1 in |
| Tank, one fish | 30 by 30 cm base | 5 gal | groups only | 5 gal |
| Tank, six fish | 2 to 3 gal each | 5 gal, then 3 each | 60 L, 15.8 gal | 15 to 20 gal |
| Temperature | 72 to 82 °F | 74 to 82 °F | 75 to 82 °F | 72 to 80 °F |
| pH | 6.8 to 8.0 | 6.5 to 8.4, ideal 7.2 to 7.5 | 6.8 to 7.8, ideal 7.2 to 7.5 | 6.8 to 7.8 |
| Hardness | 5 to 25 dGH | not stated | 7 to 12 ideal, 5 to 25 reported | 8 to 16 dGH |
| Community tank | species only | species only | not phrased that way | best in species only |
Reading the hardness row down is the most useful thing this table does. This record carries 90 to 448 ppm, which is Seriously Fish's 5 to 25 dGH and the widest range on the site. Two of the newer sources narrow the ideal sharply inside it, to 7 to 12 and 8 to 16 dGH, roughly 125 to 285 ppm. The tolerance and the target are not the same figure, and until now this record only held the tolerance.
The teeth question, where a specialist disagrees with the hobby
Seriously Fish states that the pea puffer needs small snails with the shell on, regularly. This record prints that requirement and gives no reason for it, because the source gives none. Everyone in the hobby supplies the same reason anyway: puffer beaks grow continuously, and hard shells wear them down.
Puffer Fish Enthusiasts Worldwide states the opposite for this species. Unlike many larger puffers, it says, pea puffers do not have beaks that grow rapidly, so they do not require frequent hard shelled foods to keep their teeth worn down.
- What does not change. Shell on snails stay on this record as a stated requirement, because a source states them. Two of the four name snails in the diet regardless of the reason.
- What is now marked contested. The dental explanation. If you have been buying ramshorns to file a pufferfish's teeth, one specialist source says that is not what is happening in a fish this size.
- Why it still matters. Neither source suggests dropping snails. What the disagreement changes is the consequence of running out of them: on the hobby explanation that is a dental emergency, and on the specialist's it is one item missing from a varied diet.
- Where the snails come from. A pest snail colony, which is why this record files the snails silo as food rather than as company, and it is the only record here that does.
Inflating, and why you should never see it
A pufferfish inflates, and the two newer sources describe it differently enough to be worth printing. Puffer Fish Enthusiasts Worldwide says pea puffers can inflate when frightened or stressed, and adds an instruction rather than a fact: they should never be provoked into inflating. Shrimpy Business describes the mechanism as ingesting air, notes it makes the fish harder to swallow, and says the process is tiring.
We are not going to adjudicate air against water, because our sources do not agree and neither of them shows its working. What both of them support is the practical reading: inflating is a stress response in a one inch animal, and a keeper who has seen it has already done something wrong.
Male or female, and the marker our record was missing
This record already told you males carry deeper color and a line or dot along the belly and that females are rounder. Both new sources add a second marker that is easier to see: closely spaced lines around the eyes on the male, which both of them describe as looking like wrinkles.
That matters more here than on most records, because the group figure is a ratio rather than a count. One male to two or three females only works if you can tell which is which in a shop tank, and belly color on a stressed inch long fish under shop lighting is not a reliable test. The eye lines are.
More than one, if the tank is planted
Seriously Fish and Aquarium Co-Op both treat a group as normal and both make it conditional, and the two later sources give tank figures for a group of six rather than conditions. Aquarium Co-Op gives the arithmetic: five gallons for the first puffer and three for each one after it, so three in a ten gallon and six or seven in a twenty with dense planting. Seriously Fish gives two to three gallons per puffer and asks for pairs or a harem.
Aquarium Co-Op states the ratio and the reason, which is that it decreases aggression. Seriously Fish arrives at the same arrangement by calling it a harem. This is the second record here where the group figure is a ratio rather than a count, after the guppy.
Aquarium Co-Op attaches it to the higher numbers rather than offering it as decoration. Plants are sight breaks between animals that would otherwise be looking at each other in a five gallon.
Males carry deeper color and a line or dot along the belly and are the more aggressive sex; females are rounder and Aquarium Co-Op adds a yellow belly. It is the second record on this site that tells you how to tell, after the guppy.
The names, and the one claim on the label
Four names for one inch of fish
Aquarium Co-Op sells this animal under three names besides the one at the top of this record: Indian dwarf puffer, Malabar puffer and pygmy puffer. The scientific name is Carinotetraodon travancoricus, and unlike most of the taxonomy on this site it is not contested by any source we hold.
The trade names are worth knowing for the reason the corydoras record gives about the albino: a shop label describes a bin, not an animal. All four names on a tank at the same shop are the same fish with the same requirements, and none of the four tells you whether it is a male.
The smallest pufferfish in the world
Aquarium Co-Op states it in as many words, and it is the fact that sells the fish. Carinotetraodon travancoricus reaches about 25 millimeters, which every one of our four sources agrees on and which is the only field on this record where all four land on the same figure.
What the claim does not carry is any of the consequences. A pufferfish an inch long still eats live food, still refuses a community tank on three of four sources, and still needs the hardest water of anything in this build. Smallest is not a synonym for easiest, and the stocking calculator puts it in mid water on its own for exactly that reason.
Where it comes from, and what that explains
The southwestern tip of India, in fully freshwater environments, per Aquarium Co-Op. The second half of that sentence is the part worth reading twice, because pufferfish as a group are mostly brackish or marine and this one is not. It is why a brackish setup, which is the right answer for several puffers people compare this one to, is the wrong answer here.
What the plants are for, in two parts
This record already said dense planting is part of the stocking figure and that plants work as sight breaks between animals in a five gallon. Aquarium Co-Op gives a second reason we had not printed: live aquarium plants help with waste management in a tank stocked with a fish that eats meat and produces accordingly.
- Sight breaks, so a harem in a small tank is not looking at itself all day. That is the reason attached to the higher stocking numbers.
- Waste management, in a tank fed live and frozen food, where uneaten protein is the failure mode rather than uneaten flake.
- Cover, which Puffer Fish Enthusiasts Worldwide describes as plenty of places to hide, for a fish that inflates when it is frightened.
- Not a substitute for volume. No source here lowers a tank figure because the tank is planted, and the aquarium plants silo records what we have verified about the plants themselves.
Questions about pea puffer care
What is the pea puffer lifespan?
Two of our four sources give a figure and they agree. Shrimpy Business says 2 to 6 years. Puffer Fish Enthusiasts Worldwide says most sources suggest an average of three years and that healthy, well maintained individuals often reach six or more. Neither Seriously Fish nor Aquarium Co-Op states one.
Read the spread rather than the midpoint. A range that runs from two to six is telling you the number depends on the keeper, which for a fish that needs live food and species only housing is exactly what you would expect.
Do pea puffers need snails to wear their teeth down?
Our sources disagree, and this is the most useful disagreement on the record. Seriously Fish states the fish needs small snails with the shell on, regularly, and gives no reason. Puffer Fish Enthusiasts Worldwide states that pea puffers, unlike larger puffers, do not have beaks that grow rapidly and do not require frequent hard shelled foods to keep their teeth worn down.
So the requirement holds and the usual explanation for it does not, on one specialist source. Keep feeding snails, because two sources put them in the diet either way, and stop treating a snail shortage as a dental emergency.
Why is my pea puffer puffing up?
Because it is frightened or stressed, on the one source that addresses the trigger. Puffer Fish Enthusiasts Worldwide states that pea puffers can inflate when frightened or stressed and that they should never be provoked into it. Shrimpy Business adds that inflating makes a pufferfish harder to swallow and that the process is tiring.
It is not a trick and it is not a sign of health. In a one inch fish it is the same category of information as a fish sitting on the substrate: something in the tank, or somebody at the glass, is the cause.
What is the ideal water hardness for pea puffer care?
This record carries 90 to 448 ppm, which is the 5 to 25 dGH Seriously Fish publishes and the widest hardness range on this site. It is a tolerance, not a target.
Two newer sources give the target. Puffer Fish Enthusiasts Worldwide calls 7 to 12 dGH ideal and says tolerances of 5 to 25 have been reported; Shrimpy Business gives 8 to 16 dGH. The overlap is 8 to 12 dGH, roughly 145 to 215 ppm, and that is the narrowest honest answer available. It is hard water, which is the opposite of what most people assume a tiny tropical fish wants.
Can pea puffers live in a community tank?
Both our sources say no, in different strengths. Seriously Fish calls it not usually recommended and describes fin nipping of slow moving or long finned fish. Aquarium Co-Op says to buy them expecting a species only aquarium and to avoid any other fish. We print the stricter position and show the other in full on this page.
Can pea puffers live with otocinclus or shrimp?
Our first two sources contradict each other here, which is unusual enough to be the reason this page exists. Of the four we now hold, three say species only. Seriously Fish names Otocinclus and some freshwater shrimp as compatible; Aquarium Co-Op says no algae eaters and no clean up crew. Our grid marks both as a caution rather than a refusal, because one source recommends them.
Will a pea puffer eat my snails?
Yes, and it needs to. Seriously Fish states small snails with the shell on, regularly, as part of the diet. That is why our records refuse the pea puffer and nerite snail pairing outright: it is not a risk assessment, it is the feeding instruction.
What size tank does a pea puffer need?
Five gallons for one, from Aquarium Co-Op, and three more gallons for each additional puffer. Seriously Fish asks for a base of 30 by 20 by 20 cm, about 12.6 liters, which is smaller. We print five, because it is the larger of the two figures our sources state.
What do pea puffers eat?
Live and frozen food, and snails with the shell on. Seriously Fish and Aquarium Co-Op both state that dried foods are usually refused, which is the commitment this fish actually asks for: nothing on the shelf that feeds the rest of this site feeds this one.
How many pea puffers can I keep together?
Three in a ten gallon and six or seven in a twenty, per Aquarium Co-Op, and it attaches dense planting to the higher numbers rather than offering it as an extra. The ratio matters as much as the count: one male to two or three females, stated to decrease aggression.
What water do pea puffers need?
74 to 82 °F, pH 6.8 to 8.0, and 90 to 448 ppm hardness. That last figure is the widest hardness range on this site and the only floor above 89 ppm, so this is a hard water fish rather than a soft water one.
How long do pea puffers live?
Two of our four sources state a figure and they agree on 2 to 6 years, which is what the field holds. Neither Seriously Fish nor Aquarium Co-Op states one. It is worth noting that one of the two sells this fish and still does not publish a lifespan for it.
How do I tell males from females?
All four sources describe it. Males are more deeply colored with a line or a dot along the belly, slimmer, and the more aggressive sex. Females are rounder, and Aquarium Co-Op adds a yellow belly. Only two records on this site tell you how to sex the animal, and this is one of them.
Do pea puffers need their teeth ground down?
Aquarium Co-Op states that they do not, unlike the larger pufferfish, and the snails they eat are shell on in any case. It is the only claim on this page that answers a question people bring from a different fish.
The snail this record asks for now has a record of its own. Seriously Fish asks for small snails with the shell on regularly, and our ramshorn snail record carries the animal that instruction usually means: 0.7 to 1 inch across the shell, hermaphroditic and multiplying without help, and named by Fishkeeping World as one of the snails puffers eat. The bands meet from 74 to 78 °F, so the pairing works in the direction this record needs and not in the other: it is a refusal on our tank mates grid because one of the two animals is food. That is now the second snail record refused against this one, after the nerite snail, and the difference between them is that this record’s source asks for the smaller one.
What this fish needs that no community tank has
Four things, and the first is a supply chain rather than a purchase.
- A source of small snails, shell onregularly, per the source
- Frozen bloodworm and brine shrimpdried food is refused
- A densely planted tanksight breaks between puffers
- A gentle filterslow flow, both sources
Every item our records ask for is gathered on the tank setup topic.
Nothing here is a paid link. It is the shortfall between what this record asks for and what a boxed kit contains.
How this record was compiled
- By
- Verified
- Sources
Seriously Fish, Carinotetraodon travancoricus, Aquarium Co-Op, Puffer Fish Enthusiasts Worldwide and Shrimpy Business
- Conflicts
Printed above, plus one refusal and two cautions against records we already hold
- Blanks
Growth rate stay empty until a source we trust states them
- Not recorded
A lifespan, a growth rate, and a hardness figure from the second source