An unlucky diner who has been poisoned by eating Fugu will know that something is amiss when he feels a tingling in the extremities and his lips turn blue.
The poison paralyses the nerves and prevents the lungs from working. There is no antidote to this type of poison and death occurs within minutes.
Only specially licensed chefs are qualified to prepare the blowfish for human consumption.
Every year, a number of people succumb to Fugu poisoning after preparing the dish at home.
But even with the dangerous nature of this fish, the Japanese are still consuming it because of its delicate flavor.
A team headed by Prof Tamao Noguchi at Nagasaki University was able to breed blowfish that had no poison in it by putting it on a special diet.
Prof Noguchi has bred 4,800 of the prized tiger fugu species over three years, preventing tetrodotoxin accumulating in their internal organs by altering their diet to eliminate crabs, shellfish and starfish.
Unfortunately, it looks like this poison-free variety of blowfish is not necessarily taking off in Japan’s restaurants. Takeshi Yamasuge, a fugu restaurant owner near Tokyo, said his customers preferred the real thing, despite prices as high as £60 a pound.
Yamasuge says that one reason people actually eat fugu is because of the danger involved in eating it.