Tetrodotoxin is mainly found in the gonads, liver, spleen, eyes, skin and blood of puffer fish.

Almost all species of puffer fish contain tetrodotoxin (TTX), which is a neurotoxin that can kill a person who ingests tetrodotoxin 0.5mg-3mg. The toxin is heat-resistant, 100 ℃ 8 hours are not destroyed, 120 ℃ 1 hour to destroy, salt pickling, sun can not destroy the toxin.

The toxin mainly exists in the gonads, liver, spleen, eyes, skin, blood and other parts of the puffer fish, ovaries and liver are highly toxic, followed by kidneys, blood, eyes, gills and skin, and spermathecae and meat are weakly toxic or non-toxic. When cooking puffer fish, you must strictly and carefully remove the viscera and eyes of the puffer fish, pick off the gills, peel off the skin, remove the sinews and blood, and wash it with water repeatedly.

Bufferfish

The body of the pufferfish is cylindrical, tapering backward, with a bare, scaleless body or covered with prickly scales, one dorsal fin, no fin spines, opposite the anal fin, no ventral fin, truncated or rounded or crescentic caudal fin, and the color of the body and the pattern varies with the species.

The river herring (Latin name: Tetraodontidae) is the collective name for fish in the genus Tetraodontidae, which are mainly found in the Yellow Sea, Bohai Sea, East China Sea, South China Sea, and the offshore rivers of China. They mainly live in the middle or bottom layer of the water, and feed on shellfish, crustaceans, and juvenile fish.