Fugu is the Japanese name for pufferfish – a member of the Tetraodontidae family of fish that contains more than 120 species worldwide including Balloonfish, Blowfish, Blowies, Bubblefish, Globefish, Swellfish, Toadfish, Toadies, Honey Toads, Sugar Toads, and Sea Squab.

Pufferfish are morphologically similar to the closely related Porcupinefish; they have no scales, but their long, taped bodies are covered in rough to spiky skin. Some have wild markings and colors to advertise their toxicity, while others have more muted or cryptic coloring to blend in with their environment.

Their scientific name refers to their four large teeth that are fused into upper and lower plates in their mouths. These unusual front chompers are used for crushing or cracking open the hard shells of crustaceans and mollusks, their natural prey. Poisonous Puffers are believed to synthesize their deadly toxin from the bacteria in the animals they eat.

Most Pufferfish are found in tropical and subtropical ocean waters, but some species live in brackish and even freshwater. They range in size from the 1-inch-long Dwarf or Pygmy Puffer to the Giant Puffer, which can grow to more than 2 feet in length.

Biologists think that Pufferfish developed their famous ability to inflate because their slow, somewhat clumsy swimming style makes them vulnerable to predators. In lieu of escape, Pufferfish use their highly elastic stomachs and the ability to quickly ingest huge amounts of water (and even air when necessary) to turn themselves into a virtually inedible ball several times their normal size. Some species also have spines on their skin to make them even less palatable.

A predator that manages to snag a Puffer before it inflates won’t feel lucky for long. Almost all Pufferfish contain tetrodotoxin in their skin, intestines, ovaries, gonads and liver. This foul tasting and exceptionally potent neurotoxin is often lethal to fish and usually deadly to humans. Up to 1,200 times more poisonous than cyanide, there is enough tetrodotoxin in one Pufferfish to kill 30 adult humans – though a lethal dose is smaller than the head of a pin. There is no known antidote.

Pufferfish poisoning symptoms typically develop within 30 minutes of ingestion, but may be delayed by up to four hours. Fatal dose symptoms usually present within 17 minutes of ingestion. Paresthesia of the lips and tongue is followed by developing paresthesia in the extremities along with hypersalivation, sweating, headache, weakness, lethargy, incoordination, tremors, paralysis, cyanosis, aphonia, dysphagia, and seizures. The gastrointestinal symptoms are often severe and include nausea, vomiting, diarrhea, and abdominal pain; death is usually secondary to respiratory failure. There is increasing respiratory distress, speech is affected, and the victim usually exhibits dyspnea, cyanosis, mydriasis, and hypotension. Paralysis increases, and convulsions, mental impairment, and cardiac arrhythmia may occur. The victim, although completely paralyzed, may be conscious and in some cases completely lucid until shortly before death, which generally occurs within 4 to 6 hours. However, some victims do enter a coma.

Should a poisoning victim survive 24 hours, a full recovery without any residual effects usually occurs over the course of a few days.

Amazingly, the meat of some Pufferfish is considered a delicacy. Illegal in the United States, Fugu has become one of the most celebrated and notorious dishes in Japanese cuisine. Its restaurant preparation into paper-thin translucent slices is strictly controlled by law in Japan and only chefs who have qualified after four or more years of rigorous training are allowed to prepare the fish. More than 20,000 tons of Fugu is consumed in Japan each year – though domestic preparation occasionally leads to accidental deaths.

A single plate of the simple, light tasting fish can cost well over $200.