Are Pufferfish Poisonous or Dangerous?

Written by Taiwo Victor
Published: February 10, 2022
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Pufferfish are known for their unique ability to “puff up” themselves whenever they face threats or predators. They are also notorious for having spikes around their bodies to protect themselves when they puff up. Indeed, pufferfish are equipped with many defense mechanisms, but one thing that makes them the most challenging prey is the toxins they contain. But are pufferfish poisonous or dangerous? Pufferfish are highly poisonous to other fish and also to humans. These fish are very dangerous to touch because they secrete lethal toxins from their bodies. However, despite their toxic nature, the pufferfish remains a famous and luxurious delicacy for humans in some regions. Extreme care and expertise in the preparation of pufferfish is a requirement because eating the fish can lead to severe food poisoning complications and even death. Pufferfish are extremely poisonous and dangerous to humans and other animals. 

Do Pufferfish Bite?

Minecraft Animal: Pufferfish

Pufferfish do not bite.

©J.T. Lewis/

Pufferfish are one of the most dangerous and deadliest fish on the planet, but the ironic thing is they do not sting or bite. They have several defense mechanisms that make them one of the most challenging prey to eat, both for animals and even humans. Pufferfish do not contain venom, so even when they bite (which they don’t), they won’t cause any harm. However, some pufferfish species have spikes or spines that help them ward off predators. If you were a predatory fish, a puffed-up pufferfish with spikes all over their bodies indeed wouldn’t look appetizing.

Pufferfish are not aggressive fish. In the wild, they are more on the side of food rather than predators themselves. They eat shrimpsnailskrill, and other shellfish in the ocean and try their best to be inedible using several defense mechanisms. These defense mechanisms include inflating themselves by inhaling air or filling themselves up with water, and exposing sharp spikes around their bodies, especially around the abdomen, to look inedible. However, apart from these defense systems, pufferfish are also unappetizing for many fish in the sea as they possess harmful toxins that can be deadly to fish and even humans.

Are Pufferfish Poisonous?

pufferfish inflated

Pufferfish have extremely potent and deadly toxins.


Pufferfish possess another unique feature that sets them apart from other fish food – toxins. The pufferfish is not only known for its distinct ability to “puff up” when threatened or when escaping predators, but it’s also known for being extremely poisonous. These fish possess tetrodotoxin, which can cause severe complications and even death to animals and humans. The toxins that pufferfish have are often used against other fish as they are highly susceptible to the effects of the poison.

Tetrodotoxin (TTX) is a very harmful and poisonous substance typically found in some fish species, including pufferfish. These toxins are also found in toadsoctopuses, shellfish, and amphibians. The potent poison is notoriously known for its typical side effects, including paralysis. Tetrodotoxin gets in the way of signal transmission from the nerves to the muscles. This event can lead to weakening and paralysis of the muscles, including the respiratory tract. The rapid paralysis of the respiratory muscles can eventually result in respiratory arrest or death. Some predators may think they are lucky to eat a pufferfish before they inflate and harness spikes, but they wouldn’t be lucky for long as pufferfish poison will eventually kill them.

Are Pufferfish Dangerous to Humans?

Star Pufferfish Juvenile (Arothron stellatus)

The toxins pufferfish secrete are extremely dangerous for humans.


Pufferfish are extremely dangerous for humans as they possess harmful toxins that can make humans sick or even die. Even though pufferfish are notorious for their poison, and despite all the pufferfish’s efforts to make themselves inedible, they are still considered a luxurious marine delicacy in some places, especially Japan. However, eating and preparing pufferfish requires utter care and expertise as these fish contain poison that is lethal to humans. Pufferfish poison is studied to be around 1,200 times more deadly than cyanide, making one pufferfish enough to kill 30 humans. The more pressing fact is that pufferfish poison has no known antidote.

Pufferfish encounters with humans in the ocean are rare. Also, pufferfish are naturally shy fish species and will not initiate attacks on humans. However, they can act in self-defense and release their spiky spines when handled. But what makes pufferfish dangerous to humans is not bites or aggressive behavior, but the poison they contain. While humans do not often encounter pufferfish in the sea, they are still available as food, resulting in many food poisoning issues.

Japan is the center of the pufferfish population, and in the country, the pufferfish, locally known as fugu, is a very expensive delicacy. Only trained chefs and approved restaurants can include pufferfish in their menu. However, some local eateries or unlicensed chefs also offer this dish, which usually causes fatalities. The pufferfish toxins are spread throughout their organs, and trained chefs need to remove all the parts with toxins from the fish carefully. One wrong cut will certainly lead to food poisoning. Heating or thawing cannot remove the poison from the fish and may even cause the toxins to migrate to the fish’ flesh.

Pufferfish Human Fatalities

The pufferfish contains high volumes of central nervous system toxins that can trigger symptoms as early as 20 minutes after ingestion. Initial symptoms of pufferfish poisoning include dizziness, exhaustion, headache, difficulty or problems with speaking, weakening or paralysis of muscles, vomiting, and diarrhea. The toxins can also lead to respiratory paralysis, resulting in death.

Every year, about 100 people die from pufferfish poison, and a high percentage of them die from consuming the deadly fish. The fatalities have been recorded over the years, more commonly in Japan and China, where fugu is served in sushi restaurants. Between 1996 to 2006, Japan reported about 44 incidents, and 6.8% were fatal. In December 2020, the latest news of pufferfish poisoning surfaced as three men ate a pufferfish prepared without expertise in the Philippines. The men died a few hours after constant vomiting.

The photo featured at the top of this post is ©

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About the Author

For six years, I have worked as a professional writer and editor for books, blogs, and websites, with a particular focus on animals, tech, and finance. When I'm not working, I enjoy playing video games with friends.

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