Pufferfish Facts and Photography Ethics Explained

Rocío freediving in deep blue water. Photo: Ocean Calling Retreats.

The pufferfish everyone photographs and almost nobody understands

You are floating over a sandy patch of reef and a small pufferfish turns to look at you, with round eyes and tiny fins working like propellers. Someone in the group lifts a camera and moves closer. A few seconds later the fish is a spiky ball, and everyone is happy with the photo. Everyone except the fish.

So here is the short answer. A puffed-up pufferfish is a frightened pufferfish, and puffing up has a real physical cost that scientists have measured. The ethical photo is the calm one, taken from a distance, of a fish that never needed to defend itself. Below are the pufferfish facts that matter, and why they change the way you hold your camera.

The toxin is real, and it is extraordinary

Pufferfish (family Tetraodontidae) are famous for tetrodotoxin, often shortened to TTX. It is a neurotoxin that sticks to the sodium channels in nerve cell membranes. This blocks the signals from nerves to muscles and can cause paralysis. It is one of the strongest natural toxins we know. The Centre for Food Safety in Hong Kong writes that some authorities consider it over 1,000 times more toxic to humans than cyanide. Popular sources often say "up to 1,200 times". The exact number depends on who you ask, so I read it as a rough comparison, not a measurement. There is no specific antidote, and people who survive poisoning do so thanks to fast medical care.

Two things are often misunderstood. First, the toxin is not spread evenly through the fish, and the amount changes by species and by organ. This is why eating pufferfish is a known food-safety risk that health authorities keep warning about. Second, pufferfish are not venomous like a stingray or a lionfish. They have no sting and cannot inject anything into a passing diver. Tetrodotoxin harms people who eat the fish, not people who swim near it. Underwater, the risk is not to you. It is to the fish, if you scare it.

Around two hundred species, and they are not all the same

Species counts vary between references. One lists 191 species in 29 genera, and Ecology Asia, citing FishBase in 2025, gives 206 species in 28 genera. Most live in tropical and subtropical seas, but about 35 species spend their whole lives in fresh water. Pufferfish have four beak-like teeth, which they use to crush hard food such as shellfish. Their close cousins, the porcupinefish (family Diodontidae, about 18 to 19 species), have the teeth joined into a single beak in each jaw, and large body spines. In everyday conversation, people call both of them "puffers".

With so many species, there is no single conservation story for the group. Some may be doing fine and others may be under pressure. If you want to know about one particular puffer, look up that species on the IUCN Red List instead of trusting a general statement, including mine.

Why do pufferfish inflate, and does it hurt them?

Inflation is defence, not a show. A threatened pufferfish pumps water into a very stretchy stomach and swells to several times its normal size within seconds. A bigger, rounder fish is harder for a predator to swallow, and in spiny species it also hurts to bite.

For a long time people thought a puffed fish was "holding its breath". A 2014 study in Biology Letters by McGee and Clark tested this with black-saddled pufferfish (Canthigaster valentini) from the Great Barrier Reef. The fish kept breathing through their gills while inflated, and their oxygen use rose to around five times the resting level. After deflating, the fish needed on average about 5.6 hours for their aerobic metabolism to return to normal. The researchers also noted that in other pufferfish species, scientists had seen fatigue so strong that the fish needed longer to recover after each new inflation.

Think about what that means on a reef. For hours after one scare, the fish spends extra energy just recovering, and it is not at its best for feeding or escaping. One inflation will not kill it. But a fish pushed to inflate again and again at a busy photo spot pays that cost every single time.

Pufferfish photography ethics, said plainly

This is where a popular photo becomes an ethics problem, not just a question of taste. A pufferfish that is poked, grabbed, cornered or chased until it inflates has been stressed on purpose for an image. Even without touching, swimming fast and straight at a small fish can be enough. A puffed fish in a photo is often proof that the animal felt threatened, not a lucky natural moment.

A resting pufferfish is not "missing" anything. It is a fish behaving normally, which is the whole point of wildlife photography. Good underwater photographers know that the calm portrait, eyes sharp and fins moving, is the harder and the better picture. And if a pufferfish starts to inflate because you or someone else came too close, that is the moment to back away and lower the camera, not to keep shooting.

Respecting wildlife: the conservation layer behind the photo

At Ocean Calling we never chase, touch, bait or manipulate wildlife, and this is true for a ten-centimetre puffer as much as for a whale. It can feel silly to worry about one small fish. But popular reefs get many visitors, and the same few photogenic animals may be approached again and again. Small habits, repeated, become pressure on the animals that live there.

There is also a quieter reason. When we stage wildlife for a photo, we teach other people that this is normal. When we share calm, honest images, we teach the opposite. For the wider principles behind these choices, our guide to ethical underwater photography and our piece on making ethical wildlife encounter decisions go deeper. Puffers also have their place in the bigger reef story, which we explore in pufferfish and coral reefs.

What this means in practice, underwater

Give pufferfish the same space you would give any reef animal: enough that your presence does not change what they are doing. Approach slowly and from the side, not head-on. Never touch, poke, block their path or push them into a corner. Keep your fins off the bottom while you wait. If the fish swims away, let it go. There will be another one.

Good photos of calm pufferfish usually come from patience and distance, not from getting close. A small underwater or action camera lets you shoot from a comfortable distance and crop later, which is kinder than leaning in. A well-fitting low-volume mask and snorkel also helps, because you can stay relaxed and still at the surface instead of fighting leaks while you wait for the fish to settle.

If you are in a group and see someone trying to make a pufferfish inflate, it is fine to say something kindly after the dive. Most people simply do not know the cost, and a friendly word usually changes the habit. Wildlife encounters are unpredictable, so always follow the local rules and your guide's briefing.

If patient, calm moments like this are the kind of time in the water you are looking for, you can explore our retreats.

Questions people ask

Is it dangerous to swim near a pufferfish?

No. Pufferfish are not venomous and cannot sting or inject their toxin. Tetrodotoxin harms people who eat the fish. In the water, the risk is to the fish if it is scared, not to you.

How toxic is tetrodotoxin?

It is one of the strongest natural toxins. Hong Kong's Centre for Food Safety notes that some authorities consider it over 1,000 times more toxic than cyanide. It blocks nerve signals to muscles and has no specific antidote.

Does inflating hurt a pufferfish?

It is costly. In a 2014 study, inflated pufferfish used around five times more oxygen than at rest and took about 5.6 hours on average to get their normal metabolism back.

Do pufferfish hold their breath when they puff up?

No. The same study found they keep breathing through their gills while inflated.

How many pufferfish species are there?

Counts vary by source, from about 190 to 206 species in the family Tetraodontidae. About 35 species live entirely in fresh water.

What should I do if a pufferfish inflates near me?

Back away slowly, lower your camera and give the fish space. Inflation means it felt threatened.

Wildlife encounters are never guaranteed and never forced. Ocean Calling works only with vetted, ethical local operators, and every animal is free to approach, or not, entirely on its own terms.

Sources & further reading

Further reading on Ocean Calling: More from the journal · Wildlife & the law · See the retreats · Ocean Atlas

Pufferfish Facts and Photography Ethics for Divers