How Does A Puffer Fish Protect Itself? {The Top 4 Ways Explained}

Have you ever seen a puffer fish blow up in size like a balloon? Is this how they defend themselves?

In this article, we’ll see that there’s much more to it that keeps puffer fish safe from harm.

How Does A Puffer Fish Protect Itself?

The puffer fish with inflate itself with water or air to make itself bigger which should scare other fish. Their spines may secrete the deadly tetrodotoxin, but their fantastic maneuverability and eyesight are their first lines of defense.

Are Pufferfish Poisonous?

Puffer fish in the wild are equipped with a naturally produced tetrodotoxin that is 1200 times deadlier than cyanide. One pufferfish can wipe out 30 humans with its tetrodotoxin secretions.

If a puffer fish stops getting access to the bacteria it gets from the wild through food sources like wild snails, it will stop producing tetrodotoxin. This makes your puffer fish that has lived its life in a aquarium unable to defend itself with this poisonous toxin.

Tetrodotoxin is processed after swimming around the bacteria in the wild. Primarily from their diet, they are able to store this toxin in the following areas:

  • Liver
  • Intestines
  • Ovaries
  • Skin
  • Spines or Spikes

The poison is a last resort defense mechanism.

How Many Ways Can A Puffer Fish Defend Itself?

A puffer fish is very intelligent. They are acutely aware and notice what is going on around them quite accurately and in a timely way. We believe this intelligence isn’t studied enough to say just how smart a puffer fish is.

Puffer fish can certainly protect themselves in more ways than one. Here are four main ways they do so. We’ve ranked them in order:

  1. Excellent eyesight
  2. Multiple fins for maneuverability
  3. Able to puff themselves out with air or water
  4. Secrete or inject poison through their spines

1. Eyesight

Many puffer fish enthusiasts claim that their puffer fish follow them around the room with their eyes. They are able to take in light and notice changes in their surrounding area that may indicate the arrival of a predator.

2. Maneuvering Fins

Dorsal, anal, caudal and pectoral fins help puffer fish maneuver very well in the water to avoid predators. They aren’t the fastest swimmers so they rely on maneuverability instead.

3. Puff Out

Swelling up with air or water makes it very hard for a predator to swallow a puffer fish. With the inability to swallow the balloon in its mouth, the predator would spit out the puffer fish and swim away.

The spines on many puffer fish stick out when they puff out. When the puffer fish isn’t threatened, those spines are barely noticeable because they lie flat and smooth on their skin.

4. Secrete Poison

Tetrodotoxin is the killer that puffer fish are carrying. First, they are going to use flight through exceptional eyesight and maneuverable fins to be crafty and get away from predators. Then, they will swell up and become practically inedible to most enemies. Finally, if all else fails, it’s tetrodotoxin time.

It’s 1200 times worse than cyanide on the human body. One puffer fish can take out 30 humans. This poison is not being produced in an aquarium because the bacteria required for it is only available in the wild.

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How Do Puffer Fish Interact With Humans?

Puffer fish get to know the person who is around them most often. This is the person that feeds them. This person is you. Their eyesight and perceptive ability to notice your movements with begging or dancing could be useful for survival.

They could get moody and sulk. They could refuse food or spit it out. Puffer fish are looking to survive in the best possible conditions. Watching you eat or focusing on the hand that feeds them, creates a sharper mind for the puffer fish to know how and when the food is coming.

Is A Puffer Fish A Predator or Prey?

The puffer fish have four front teeth fused together and routinely chomp on shells of snails, clams and other crustaceous species with rather ease. They need to use their teeth to grind them down because they won’t stop growing.

They are hunters. Puffer fish need to feast on various proteins and they are definitely predators that can use their teeth and swimming maneuvers to catch and consume their fair share of nutrients from the wild.

They are also hunted. Larger predators will most certainly attempt to swallow a blowfish or pufferfish. They’ll defend themselves to the death.

How Do Puffer Fish Protect Themselves From Getting Sick?

Puffer fish don’t have scales. They need the water parameters to be ideal for them. They aren’t the best tankmates. We are the ones who are going to protect puffer fish in aquariums. We do so by maintaining the water and feedings for their optimal health.

Puffer fish have a slimy skin coating that makes it harder for harmful particles and parasites to latch on. The gills are more susceptible to catching parasites like Ich, but the defense system of having a slimy coating protects them well.


Puffer Fish are loaded with defense mechanisms and perceptive awareness for survival. They can blow up in size or secrete poison that is deadly. They learn to adapt in their environments and understand how, when and where to get the food they need to live and thrive while protecting themselves from predators.

Brian Arial

Brian Arial has kept fish for leisure and worked with fish stores for most of his life. He enjoys writing and caring for aquariums and ponds.