The pufferfish, scientifically known as the river puffer, is an animal in the puffer family of the order Pufferiformes, with the two most common being the dark-striped oriental puffer and the red-finned oriental puffer.
The pufferfish toxin is a colorless needle-like crystalline substance that belongs to the acid- and heat-resistant animal bases and is one of the most toxic non-protein substances in nature. At one part in 50 million, it can anesthetize the nerves within 30 minutes, with a minimum lethal dose of 0.5 milligrams to humans. This extremely powerful toxin, however, is soluble in water, readily soluble in dilute acetic acid, and begins to char at 240 degrees Celsius. In a weak alkaline solution (treated with 4% sodium hydroxide for 20 minutes), it is immediately destroyed to a glucose compound and loses its toxicity. Heating at 100 ℃ for 4 hours or 115 ℃ for 3 hours, or 120 ℃ for 30 minutes, or more than 200 ℃ for 10 minutes, then the toxin can be completely destroyed, the toxicity disappears.
Tetrodotoxin is distributed in liver, gonads, liver, intestines, stomach and blood, etc. The size of its toxic content varies with different breeding environments and seasons, and the toxicity of each organ is compared as follows according to the examples of the Yangtze River Puffer and artificially cultured River Puffer: ovary→spleen→liver→blood tendons→eyes→gill rakers→skins→seminal nest→muscle. The toxicity of the organs of cultured river herring (above 2 years old) is the same as that of wild river herring, but the amount of toxin is lower.