Common misconceptions about pufferfish

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.

Dichotomyctere nigroviridis

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.

Tetraodon miurus

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.

Tetraodon schoutedeni

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.

Carinotetraodon travancoricus

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)!