This was such an interesting story shared by Professor Teruo Miyazaki during his round Australia presentations.
Traditionally, fugu (literal translation means ‘river pig’) was only allowed to be served by the certified Japanese chefs who were trained to remove the poisonous parts of the fish. The tetradotoxin is normally present in high amounts in the liver, skin and gonads of the fish; where 1g of liver is sufficient to kill two adult humans! Why would people knowingly eat such a fish? I guess the flesh is delicious and it’s the thrill of playing ‘Russian roulette’, Japanese style!
So this is how the story goes… One day, a tiger puffer fish farmer brought home some of the fish and some of the fish that had died were tossed out in his yard. Then a neighbours dog came by and ate the fish! The fish farmer became distressed and was extremely apologetic to his neighbour, that his dog would die from the poisonous meal. But the next day, the farmer couldn’t believe his eyes when he saw the dog was waking around, unharmed and ‘undead’! That’s very strange because the number of fish it ate would have killed the dog 10 times over. So the farmer fed the dog the fish on two other occasions and the dog survived! He then took it upon himself to eat the fish. He thought that the flesh and liver of the fish were delicious, and did not suffer intoxication. He then brought some of the cultured fish to the university to examine for the presence of toxin and it was found to be negative!
The scientists were puzzled over this finding. The wild caught puffers contained the toxin, whereas those that were cultured did not. How and why can this be so?
Further investigation revealed that the puffer fish do not manufacture their own toxins, but they obtain their toxin from grazing on benthic organisms, absorbing and concentrating it in their liver, gonad and skin!
And so, this is how it was discovered that the aquacultured fugu fish is non-toxic. Interesting huh?
