In the body, tetrodotoxin blocks sodium channels that enable nerves to fire. It kills because nerves no longer trigger muscle movement controlling breathing and the victim suffocates. The toxin can also induce heart failure.

Fugu contains lethal amounts of the poison tetrodotoxin in its inner organs, especially the liver, the ovaries, eyes, and skin. Researchers have determined that a fugu’s tetrodotoxin comes from eating other animals infested with tetrodotoxin-laden bacteria, to which the fish develops insensitivity over time.

Blowfish, also known as the dish fugu, is an expensive winter delicacy that requires a special license to prepare because, if handled incorrectly, it can kill the person eating it. Paralysis follows, and then a painful death by asphyxiation. There is no known antidote.

Puffer fish contain a toxin called tetrodotoxin which is one of the most deadly natural poisons. However, it is still not uncommon for poisoning and even death to occur. Pufferfish, either alive or dead, can be fatal to both humans and dogs alike if ingested in large enough quantities.

They are very poisonous if eaten so be very careful in certain countries because they are a delicacy in some places. Originally Answered: Are puffer fish poisonous when dead? Yes obviously. Unless they were aquarium raised and never had access to the foods that contain the bacteria that produce the toxin.

Of course, this would harm the puffer fish, and if it were unable to heal itself or otherwise recover from the puncture, especially if it was a large wound, the fish would likely die in the wild due to screwed up buoyancy, lack of its defence mechanism (inflation), as well as blood loss and intense pain.

Not venomous, mind you, they don’t bite or sting. But their bodies harbor a toxin 100 times more lethal than cyanide. Each year, dozens of adventurous human diners (and an untold number of underwater gourmands) are stricken with puffer fish poisoning.

When a puffer fish puffs up, it takes in water to increase the size. This violently forces the puffer’s organs to be pressed to the side, inside the body causing the organs to flatten. This creates an extreme amount of stress for the puffer fish. In some cases the puffer fish dies from this stress.

But this trick may actually tire pufferfish out and put them at risk of being eaten once they’ve deflated, a new study finds. Pufferfish, also known as blowfish, can quickly expand by gulping water into their elastic stomachs.

No. Puffing up is their defense against being swallowed by predators.