Updated: May 8, 2020
Pufferfish are one of the most misunderstood groups of fish in the fish keeping hobby. One of my main focuses is promoting the welfare of these fascinating fish through education.
In this article, I would like to clean up some common misconceptions about them.
Do all pufferfish need brackish water?
No. Pufferfish can be found in the ocean, brackish and freshwater habitats across the globe.
While it is true that there are many more species of pufferfish which require brackish or marine conditions, some species are actually completely freshwater.
Do all pufferfish need to eat snails?
Nope, not all of them. Every species of pufferfish have ever-growing 'teeth' that need to be kept ground down to maintain them at a healthy length, but methods of doing this vary from different species
The natural diet of some species includes gastropods and crustaceans, like snails and crabs, whose shells or hard exoskeletons help maintain the teeth of the pufferfish by wearing them down when the fish is chewing them. Some piscivorous species of pufferfish, like the Tetraodon miurus, maintain their teeth in a different way, by crunching through the bones of the fish that they eat and don't eat snails or crabs at all. Some species, such as the Auriglobus modestus, even eat seeds as a part of their natural diet.
Are pufferfish aggressive?
Some of them are very aggressive, others are relatively friendly and some are somewhat in the middle. Generally, the Tetraodon mbu are safe to keep in a group alongside some other carefully selected fish.
Yet, the Tetraodon lineatus - which is a close relative of Tetraodon mbu - is highly aggressive and should not be kept with any tank mates (including members of the same species) because it will likely kill them.
Then there are other species who are highly gregarious, like the Colomesus asellus, who should not be kept alone because they get too nervous. The Tetraodon schoutedeni is another species which can be kept in groups, alongside other fish. Although some of the species mentioned above are among the 'friendliest' of puffers, I would still recommend stocking other fish cautiously because they are still puffers, who can misbehave sometimes.
Do all pufferfish grow big?
The short answer to this question is that pufferfish come in small, medium, large, XL and XXL.
The smallest species of pufferfish is the Carinotetraodon travancoricus, which grows to around 2.5cm (0.98 inches) in length.
The C.travancoricus is probably the most popular species which is kept in captivity, owing to their convenient size and the fact that they can be kept in groups and are a freshwater species. The largest freshwater species is the Tetraodon mbu, which can grow to lengths in excess of 80cm (31.5 inches).
Arothron stellatus is the largest of all the pufferfish, achieving lengths of 120cm (47.24 inches)!
Do pufferfish bite?
Some will bite you, either intentionally or accidentally, others will avoid your hands. If we take a look at the Carinotetraodon travancoricus, that's a species who will typically avoid your hand when it is put into the aquarium; unless you're offering food.
Medium sized species, such as Leiodon cutcutia or Dichotomyctere nigroviridis, may nip you out of curiosity, but is very unlikely to break the skin. Some of the larger species, such as the Diodon hystrix, Tetraodon mbu and Arothron stellatus, could potentially bite a finger clean off!
Are pufferfish hard to keep?
I don't think that they are difficult to keep, but I think it is important that the keeper is aware of the specific needs of the particular species they are keeping.
Knowing about your pufferfish can help a long way in ensuring that you are feeding your pufferfish the correct foods, keeping it in the appropriate water values, in the right size tank, at the correct temperature and can also help you in creating a tank that your pufferfish is comfortable in so both you and the fish can enjoy it at its best.
The common theme here is that they are all different.
Different puffers have different diets/prey, different hunting techniques, different mating rituals, different brood care, different temperaments, different habitats, different water parameters… they’re all different.
Instead of banding them all together as "pufferfish", we should be looking at them as an individual species, like we do with any other fish.