In fact, tetrodotoxin is not produced by puffer fish itself, but comes from a special kind of bacteria. The bacteria enter the puffer fish by parasitizing on plankton, or live directly in puffer fish. The puffer fish can tolerate this toxin and use it as a means of mutual destruction with natural enemies.

There are more than 200 species of puffer fish in the world, and there are about 40 species in China. Different species of puffer fish have different positions and abilities to deposit toxins. If tetrodotoxin is concentrated in the liver, blood, ovaries and other parts, then after carefully removing these parts, the remaining meat can be eaten. This is why the cooking of puffer fish needs a specially trained chef to operate.

Extended data tetrodotoxin, a marine toxin existing in puffer fish, salamander, spotted toad and other animals. The molecular formula is c11h17n3o8. Colorless prismatic crystal. Unstable to heat. Insoluble in water, soluble in weak acid aqueous solution.

It is easy to decompose in alkaline solution and unstable in low pH solution. Tetrodotoxin is a strong neurotoxin, and extremely low concentration of tetrodotoxin can selectively inhibit sodium ion from passing through nerve cell membrane. Tetrodotoxin has other pharmacological effects and is a useful tool for neurophysiology and muscle physiology research.

Its toxicity is equivalent to 1250 times of the highly toxic drug sodium cyanide, and only 0.48 mg can cause death. In fact, the muscles of puffer fish are toxin-free. The most poisonous parts of puffer fish are ovary and liver, followed by kidney, blood, eyes, gills and skin. The toxicity of puffer fish is also related to its reproductive cycle. The puffer fish with eggs is the most toxic in late spring and early summer. This toxin can make people nervous paralysis, vomiting, cold limbs, and then stop heartbeat and breathing.

Beijing Youth Daily-Can you really eat more puffer fish and salmon?