FAQs about Freshwater Puffers
Q: Are there really freshwater pufferfish?
A: Yup, a little bit over 30 different species, actually (not counting species that do best in brackish water when in captivity). There’s plenty of small, medium and large-giant sized puffers to choose from; I’m sure you’ll find the perfect puffer for your tank. Take a look at this list of known species of freshwater puffers if you want to learn more.
Q: So, these puffers don’t need any aquarium salt, whatsoever?
A: Nope, they really don’t. True freshwater puffers don’t need brackish water conditions, even though many pet stores will tell you that you need to put aquarium salt in their water. However, you can still use aquarium salt for its therapeutic properties with freshwater puffers. For instance, it’s really easy to treat fish ick with aquarium salt and heat, which isn’t as harsh on scaleless fish.
Q: How do I know if a puffer is really freshwater?
A: The only way to know for sure if the puffer you want is a freshwater fish is to do your own preliminary research before making a purchase. Many pet stores mislabel their fish, and some just don’t know about freshwater pufferfish at all. Make sure you come prepared with the scientific name for your puffer as well, because basing your purchase off of common names is very unreliable – the common name could extend to several different species of puffer. An example of a scientific name is Tetraodon lineatus; the common name in this case is usually Fahaka puffer.
Q: I just got a freshwater puffer from Wal-Mart, but now it has a dark belly?
A: If you purchased a puffer from Wal-Mart, then you probably brought home a little neon green pufferfish with black spots. This is not a freshwater pufferfish; green spotted puffers (GSP) are actually brackish water aquarium fish, and they will not thrive for very long in a pure freshwater tank. You will need to purchase marine salt to create a brackish environment – regular aquarium salt, like this one from API, does not make brackish water.
Q: Why do puffers get a dark belly?
A: There are several reasons why puffers get a dark belly; the most common reason is stress related. If your puffer has a black belly, then check to see if you have correctly set up their puffer tank. For instance, are you using an aquarium heater? Are you keeping your freshwater puffer in freshwater, or your brackish water puffer in the proper salinity? Are you doing large, frequent water changes to remove the toxic Ammonia and Nitrite? What are you feeding your puffer? Do you have enough hiding places for them to explore and feel secure with? Are you keeping your puffer with other fish?
Sometimes, freshwater pufferfish darken their belly because they are bored. If your puffer is bored, then they will also glass surf in addition to no longer having a white belly. You can fix this by creating a more interactive environment for them to explore, like adding driftwood caves, live plants and other aquarium decorations to break up their line of sight.
Q: What are other signs that my freshwater puffer fish is stressed?
A: A stressed freshwater pufferfish will breathe abnormally, fade in coloration, darken its belly, clamp its fins, and either sit on the bottom of the aquarium or frantically glass surf. If your puffer is bottom sitting, you may notice that it has its tail tightly curled into its body – this is a sign of a very unhappy puffer.
Q: Why is a puffer able to puff up so big?
A: Freshwater pufferfish have very stretchy, elastic skin due to its pleated nature. In conjunction with the absence of ribs and a special stomach, they are able to draw in enough water to inflate their bodies several times their normal size.
Q: Can I make my pufferfish puff up? I want to show my friends!
A: No, please don’t do that. Since the only way you would be able to force your puffer to puff up is to cause them considerable amounts of stress and fear, or pull them out of the water (which can kill them), making them puff for your own amusement is a very cruel thing to do.
However, you may be lucky enough to see your puffer naturally puff up on its own – sometimes, puffers inflate themselves for seemingly no good reasons, which is affectionately dubbed “practice puffing” by enthusiasts. Make sure you get pictures if you catch your puffer puffed up so you can have them to show your friends if they ever ask you to make your puffer inflate itself!
Q: Are puffers really poisonous fish?
A: Yes, puffers contain a very powerful neurotoxin in their skin and organs called Tetrodotoxin, which is bacterial in nature. Just don’t try to eat your puffer, and always wash your hands thoroughly after dealing with a freshly wild caught puffer and you’ll be fine.
Q: Can I keep my freshwater puffer with any other fish?
A: In most cases, the answer is no. Generally speaking, freshwater pufferfish are very territorial, predatory fish – they don’t play well with others.
Q: Can I keep my puffer with other pufferfish?
A: This normally isn’t a very good idea. Your puffers will constantly have territorial spats, and one will eventually end up eating or killing the other weaker puffer. There are exceptions to this rule, like dwarf puffers and SAP’s.
Q: I’ve heard that a puffer’s teeth are always growing – how do I stop them from getting too long?
A: In order to prevent your freshwater pufferfish from having overgrown teeth, you will have to provide them with a consistent diet of hard, crunchy foods. Good food items for wearing down a puffer’s teeth include: whole shrimp, ramshorn snails, common pond snails, clams, live feeder crabs, crayfish, and other types of mollusks.
Q: What other foods are good for my puffer?
A:In addition to hard, crunchy foods, you can also offer your freshwater puffer blood worms, feeder insects, and night crawlers – to name a few. Don’t feed your puffer feeder fish unless you have a true piscivorous puffer species, like the Congo puffer (Tetraodon miurus).
If you have a fish-eating species of puffer, then you will need to raise your own feeder fish so that you can ensure they are healthy before offering them as food – do not offer your puffer feeder fish from the pet store unless you have quarantined them first, and stay far away from feeder goldfish.
Q: I just set up my puffer tank. Can I get a freshwater puffer today?
A: No, that wouldn’t be a good idea. Freshwater pufferfish are scaleless fish, which makes them very sensitive to their environment and some medications. You should never add a puffer to an uncycled tank – taking the time to let your tank mature before making a purchase will mean the difference between a thriving and dead puffer.
Q: Do you recommend any resources or books on freshwater pufferfish?
A: One of the best resources on freshwater puffers is the book Aqualog: The Puffers of Fresh and Brackish Waters by Klaus Ebert. Although it’s a little bit pricey, I highly recommend purchasing it if you are serious about keeping freshwater puffers. Although the author states that the book is not meant as an identification guide, the many in-color pictures that the book provides are a wonderful way to figure out what puffer species your local pet store is really selling.
In addition to the Aqualog book, you can also purchase my instantly downloadable guide, the Beginner’s Guide to Keeping Freshwater Puffers. I cover all the basics of puffer care, including diet, temperament, tank setup, raising your own feeder cultures, picking out the right puffer species for your tank, and how to acclimate your puffer when you finally bring it home from the pet store.