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Cover Images


Things That My
Puffers Have Told Me

By Justin Petrey

This Diodon Holocanthus is a great example of one of the species that does not always exhibit the same signs as other puffers.  Note the iridescent sheen on the eyes.  This is a clear indicator of health, as is the straight back.  A bent or hunched Diodon puffer is generally too cramped and needs a larger space.  Also the colors are bright and well defined.  Photo by Justin Petrey

You know it, you’re guilty.  If you are reading this section you have been bitten by the friendly fat-dog-like antics of a Pufferfish.  Be it a Tetraodon, a Diodon or even the Ostraction.  I do not know why nature gave such cute looks to a fish that can be so aggressive!  I think they were intended as “aquatic dogs”, as we all know how hard it is to punish a cute face.  They win hands down for begging and being evil, be they small or large!

I love my Porcupine Puffer as I have every Puffer that I have ever had.  I have, unlike many hobbyists, been willing to experiment with tank mates and training after reading several articles on the ability and success that several aquarists had training a Diodon histrix to respond to a sort of “sign language”, so that it would not eat the food  intended for the Eel with whom it was housed.  I began a series of tests and began experimenting with medication practices as well.  This gave me a “fin up”, if you will, on keeping Puffers because now I had a “trained” animal whose responses to my actions told me volumes about its health and stresses.

 Here are some major signs puffers have to tell us what’s on their minds:

  • The belly:  The universal way to tell if the Tetraodon species is stressed, or sick.   As a rule, a white, fat belly is an indication of a happy, healthy Puffer.  Diodon species do not have this telling sign; subsequently their health is harder to gauge.

  • The eyes:  A healthy Puffer is always curious, and will explore the tank, looking for food, or anything that attracts its attention.  If it favors one eye or swims the tank aimlessly without normal “stop-and-investigate” procedures, it is a sign of possible stress, illness and/or blindness. 

    Another Photo of Diodon holocanthus.  This photo shows the relatively flat belly of this species as they digest food more rapidly.  A concave belly and shrunken areas near the tail are major indicators of illness or being underfed.  Photo by Justin Petrey

  • Puffers generally DO NOT inflate unless they are stressed in some way.  You want to avoid this occurrence as much as possible as getting air trapped in them can be deadly. An inflated Puffer is usually not a happy Puffer, and this can be a sign of possible health issues. On the other hand, otherwise healthy Puffers have been known to inflate on occasion for no apparent reason.

  • Pacing.  If your Puffers are constantly cruising the tank that is okay.  Constant up and down pacing usually means they are “bored”. However, hidden in this seemingly cute display might be a cry for help.  Do not ever dismiss the Puffer that is pacing too much. Investigate to determine what could be causing this behavior

  • Last but not least, Puffers are the aquatic version of  pigs.  The average Puffer can eat at least three times its weight in food.  Its belly is folded hundreds, if not thousands of times, and so it can expand greatly.  A Puffer cannot really eat itself to death, although I have had a few Green Spotted Puffers that couldn’t get off the bottom and bobbed up and down for a few hours as the food settled in their stomachs.


This works for me and has worked in many tanks that have carefully logged information and proactively handled the issues that arose.  If you don’t observe your fishes carefully, you will have problems.

Ok, now that that is out of the way, here you go:

  1. For those of you with sumps or refugiums on your tanks, if you can get a macro algae or plant to grow well in there, you can do less water changes.  Generally, freshwater tanks with plants or marine tanks with macro algae tend to maintain higher water quality and do fine with bi-weekly or monthly water changes.  You will be replenishing valuable trace elements through these regular changes.  Simply adding trace elements and topping off evaporative water is not enough to assure healthy specimens. Do those water changes!

  2. Most Puffers seem to do better with extensive “passive” filtration provided through the use and harvest of macroalgae , live rock and plants.  The more plants and live rock you add (coupled with regular water changes), the better off the Puffers are since they cannot trash the water quality quite as easily regardless of their feeding habits. Of course, these export mechanisms are no substitute for sound maintenance practices.

    This photo of Colomesus asellus (South American Puffer) proves it's heatlh by the nice white belly that is not too big, but not concave as well as clear color patterns and it's clear eyes.  All are great barometers for this species to gauge it's health.  Photo by Damien Wagaman

  3. All Puffers seem to do better in slightly cooler temperatures.  Drop that tank temp to 74 degrees F, or even 72 degrees for larger puffers, and you will notice that your supplies of food last longer, the Puffers tend to “pace” less, and seem more content in your aquarium.  This is because the cooler temperatures reduce metabolism. Many fish breed in the water temperatures we tend to maintain (79-82 degrees F).  I have theorized that Puffers are exactly the same way and that a decreased temperature can decrease aggression.  <Editors’ note: It is possible that some Puffer species may actually have a more difficult time digesting food at lower temperatures and be more susceptible to illness, so do research your species carefully>

  4. Want a tankmate for your Puffer? Get a fish that is as aggressive as the calmest Puffer in your aquarium.  In freshwater, this means fishes such as Bichers, Blue Acara Cichlids, and many Gobies.  As long as the tankmates are significantly larger (2 to 3 inches) than the Puffer, I have never had a problem.  Your Puffer’s temperament may be vary, so be careful and observe your fish extensively before adding tankmates.  I have never had a truly “evil” Puffer, and the one that was  never bothered the resident Acara who was 3 times his size!  In saltwater, look at some of the larger Damsels, Eels and Clownfish.  Invertebrate-wise, Hermit Crabs and snails in are a calculated risk. Their shells are generally too hard to get through, but they may still become “Puffer snacks” in time, especially if the Puffers learn to pry the crab’s softer body out of the shell. If you feed them frozen foods, the Puffers may not bother other items they no longer see as “food”. A well-fed Puffer is less likely to casually eat your invertebrates.

Here is where it gets tricky, though: 

  1. Puffers do not generally “unlearn” habits they get from residing in our tanks.  I will use my last Porcupine Puffer as an example.  I kept him with Percula Clownfish and no anemones.  At night the Clownfish slept on the substrate in the open.  Well, one died and the Puffer “sampled” and ate the body.  I went to get another Clownfish, and found it dead the next morning, and the big female missing a fin.  I stayed up the next evening to see what was happening. Well, every time the Clowns went to sleep, the Puffer would nudge them, and when they didn’t move, he would try to eat them.  The bottom line here is: Be careful with what you allow your Puffers to do, or what they pick up on will stay with them.

    This Tetradon nigroviridis is a great example of brackish to saltwater puffer whose large and well rounded belly and well defined color patters point to a healthy puffer.  Having cloudy eyes is a good indicator that this species is ill  Photo by Damien Wagaman

  2. Generally, the best captive Puffer environment is one that mimics the one they came from in the wild.  I know it seems obvious, but it is often overlooked by hobbyists.  Doing basic research and providing a captive environment that simulates the Puffer’s natural environment as closely as possible dramatically improves their overall health and activity levels. I cannot say it enough:  A busy and fat Puffer is a happy puffer!

  3. Saltwater Puffers and corals are not supposed to be mixed.  I personally have had no problems, even with coral species the Puffers have never seen before.  If well fed, they leave everything alone.  Also, in my experience Featherdusters and Sea Squirts are not in danger from the Puffers. Nor are live Scallops, as they are viewed as non-prey items.  <Editors’ note- Again, heed Justin’s caveat that this is HIS experience. Your results may be radically different. It’s a calculated risk to keep Puffers with sessile invertebrates, regardless.>

  4. Puffers and anemones usually DO NOT mix.  Puffers are bright, but sometimes they are not bright enough to realize that a sting is supposed to keep them away.  Rather than posing a problem to an anemone, as most experts say, I’ve had a puffer become anemone food after it kept trying to get in and grab a piece of flake food, of all things…..

Medications deemed “Puffer Safe”, based on my extensive LFS and personal use:

  • Jungle products “Fungus Eliminator”:  It’s a mixed antibiotic medication, that   is safe for scale-less fish like Puffers

  • Formalin:  The end-all, be-all, drug for all parasite problems, as far as I’m concerned.  Watch the water quality while using it, however. 

  • Methylene Blue: Not a bad supplemental treatment.  If the illness is not virulent, try this first.

To treat Ich and endo /ecto parasites, the dipping method I explain below seems to be a better option than hospital tanks, if it is not a virulent problem.

Tips on using medications for stressed puffers, also for wounds and tail rot or missing fins:

Consider dips and baths.  Puffers are incredibly hardy fish given good water quality.  Bolster the food with vitamins, pull some tank water into a 5-gallon bucket, and put in the meds. Be sure to scoop out the Puffer with a pitcher or container of tank water, instead of a net, so that it does not puff up with air. Then put the puffer in and let it swim for 20 minutes or so.  A simple powerhead and mini heater is enough here.  Keep up the dipping several times a day, and keep an eye on things.  You may notice the fish perks up a lot faster, and heals faster too.  I do not have hard facts on this either, other than my personal successes, but it works as well as a constantly maintained hospital tank, in my experience.  The Puffer gets the meds but also is returned to the tank that he is used to, For some reason, a “depressed” puffer can’t kick things, while a “happier” one has no problems, in my experience.  And, after all, we all want happy Puffs!

For maximum success and happy, healthy Puffers, listen to what they are trying to tell you!

Puffers on WWM

  Puffers of All Kinds, Puffer Care and Information by John (Magnus) Champlin, A Saltwater Puffer Primer: Big Pufferfish! by Mike Maddox, & FAQs: Marine Puffers, Marine Puffers in General 2, Marine Puffer Identification, Marine Puffer Behavior, Marine Puffer Compatibility, Marine Puffer Selection, Marine Puffer Systems, Marine Puffer Feeding, Marine Puffer Feeding 2, Marine Puffer DiseaseMarine Puffer Disease 2, Marine Puffer Disease 3Marine Puffer Disease 4Marine Puffer Disease 5, Marine Puffer Disease 6, Marine Puffer Disease 7, Puffers & Kin & Crypt, Marine Puffer Reproduction

     Pufferfish Dentistry By Kelly Jedlicki and Anthony Calfo & FAQs,

     Puffy & Mr. Nasty, a tale

  Regional Accounts:

  Systematic Accounts:

      Boxfishes, Cowfishes, Family Ostraciidae & FAQs, FAQs 2, Boxfish Identification, Boxfish Behavior, Boxfish Compatibility, Boxfish Selection, Boxfish Systems, Boxfish Feeding, Boxfish Disease, Boxfish Reproduction,

      "True" Puffers (Smooth, Blow-Up), Family Tetraodontidae & FAQs, FAQs 2, FAQs 3Tetraodont Identification, Tetraodont Behavior, Tetraodont Compatibility, Tetraodont Selection, Tetraodont Systems, Tetraodont Feeding, Tetraodont Disease, True Puffer Disease 2, Tetraodont Reproduction,

             Freshwater to Brackish Water Tetraodont Puffers & FAQs 1, FAQs 2FAQs 3, FW Puffer Identification, FW Puffer Behavior, FW Puffer Selection, FW Puffer Compatibility, FW Puffer Systems, FW Puffer Feeding, FW Puffer Disease, FW Puffer Reproduction,

             Brackish to Seawater Tetraodont Puffers & FAQs 1, FAQs 2FAQs 3BR Puffer Identification, BR Puffer Selection, BR Puffer Compatibility, BR Puffer Systems, BR Puffer Feeding, BR Puffer Disease, BR Puffer Disease 2, BR Puffer Reproduction

             Sharpnose Puffers, Tobies, Subfamily Canthigastrinae & FAQs, FAQs 2, Toby Identification, Toby Behavior, Toby Compatibility, Toby Selection, Toby Systems, Toby Feeding, Toby Disease, Toby Reproduction,

     Burrfishes, Porcupinefishe, Family Diodontidae & FAQs, FAQs 2FAQs 3Burrfish Identification, Burrfish Behavior, Burrfish Compatibility, Burrfish Selection, Burrfish Systems, Burrfish Feeding, Burrfish Disease, Burrfish Disease 2, Burrfish Reproduction,


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