Poisonous fish can be roughly divided into three categories: the first category is stinging fish, which has poisonous glands and can secrete venom. The fish with thorns will stab the human body through its thorns, and the venom will be imported into the human body, causing poisoning. These fish are highly toxic and weakly toxic. When people are stabbed by it, it will cause swelling, severe pain, fever, dizziness, nausea, vomiting, spasm and unconsciousness. If they are not rescued in time, they will die, and the fish with thorns are the most poisonous. Followed by ghost fish (tiger fish) and lionfish (lionfish), there are poisonous glands at the base of dorsal fin spine. The second category is poisonous fish, that is, all kinds of fish, whose liver, ovary, skin, blood and intestines all contain tetrodotoxin, of which tetrodotoxin is the most. Fresh puffer fish, handled well, will not be poisoned after soaking in water, but after death, the fish will deteriorate and be easily poisoned after eating. Tetrodotoxin is a neurotoxin that can block the transmission of nerve excitement. After poisoning, people will get sick quickly and have serious symptoms. Within half an hour, they will have itchy lips and tongues, which will spread rapidly, leading to dyskinesia, quadriplegia and eventually death due to respiratory and circulatory failure. The third category is other poisonous fish. Some fish muscles are also poisonous, but not every fish is poisonous, such as grouper and Napoleon wrasse. People generally eat nothing, but these fish eat toxic dinoflagellate, or other herbivores eat toxic dinoflagellate, and then groupers eat this toxic animal and accumulate toxins on themselves. People will be poisoned if they eat this grouper again. The bigger the coral fish such as grouper and Napoleon wrasse in the restaurant.

Stone fish is the most poisonous fish in the world, and it is also a master of camouflage, which can perfectly blend with the bottom of the sea. Stone fish will not take the initiative to attack, but if you accidentally step on it, you will be paralyzed and die.

The stone fish is smooth and scaleless, with a crescent-shaped mouth, gray stones on its back, and stone lines looming; The protruding abdomen of the fish is white and reddish, and the flat side of the tail is slightly narrow.

It is only about 30 centimeters long, hiding under the sea floor or rocks, disguising itself as an inconspicuous stone. Even if people stand by, it won't move and people can't find it. Stone fish belongs to Silurian system, with thick and round body and many tumor-like protrusions, like toad skin. Colors are complex and changeable, and change with different environments. Like a chameleon, it blinds its enemies through camouflage, thus enabling itself to survive. Usually khaki and orange. Its eyes are special. They grow on their backs and are very small. There is a deep depression under the eyes. Often perched on the rock wall in the sea, it looks like an unremarkable stone. Its predation pattern is very interesting, and it often waits for the arrival of food by waiting. Its hard spines (the poisonous glands at the base of dorsal fin spines are neurotoxic) are fatal and highly toxic.

Stone fish is a kind of fish with strong toxicity in nature, and its "deadly sting" is described as the most painful sting of human beings. Stone fish looks unremarkable, with a length of only about 30cm. They like to hide under the sea or rocks and disguise themselves as inconspicuous stones. If someone accidentally steps on it, it will immediately fight back rudely and send out deadly venom. Its back has needles as sharp as 12 to 14 needles, which can easily penetrate the soles of shoes and puncture the soles of feet, causing rapid poisoning and severe pain until death.

Poisonous fish can be divided into three categories: botulism fish, spiny fish and skin mucus fish. For example, botulinum fish can be divided into small snakes, small spotted double-plough eels, spotted nine-spined bass and so on. Poisonous fish include rabbit shark, horn shark, silver mackerel, sea catfish and so on. The fish with toxic skin mucus is the five-leaf goby.