Tetrodotoxin, a Japanese scholar, was first discovered from puffer fish in 1909 and named tetrodotoxin. 1950 ~ 1957, Yokoo Hiroshi, Tsuda Fujisuke and others first isolated crystalline tetrodotoxin from the ovaries of Dongfanghong Fin Fish Pond and Oriental Purple Fish Pond.

Tetrodotoxin is a kind of 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, there is no toxin in the muscles of river otters. 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.