Why are farmed puffer fish non toxic?

Tetrodotoxin. It's not the puffer fish itself, it's a special bacterium. This bacterium lives by parasitizing on plankton.

or live directly inside the pufferfish. The puffer fish is able to tolerate this toxin and uses it as a means of dying out against predators.

Some species of puffer fish have a very low ability to deposit toxins, and are virtually non-toxic after being bred and cultured under controlled conditions. In 2016, the state liberalized the operation of redfin pufferfish and dark striped pufferfish. Units that have obtained business qualifications can legally operate these two types of farmed pufferfish, and consumers can eat them with confidence.

The wild puffer fish is poisonous and illegal, and its scarcity combined with the chase for the "wild" makes it expensive. Whether it is from the perspective of **, safety or law-abiding, consumers should not pursue it. The artificially bred puffer fish is safe and non-toxic, **close to the people, and can be eaten with confidence.

Clinical manifestations of tetrodotoxin poisoning.

1. Gastrointestinal symptoms: nausea, vomiting, and abdominal pain soon after eating.

or diarrhea, etc. 2. Symptoms of nerve paralysis: numbness of the lips, tip of the tongue and fingertips at the beginning; This is followed by numbness and drooping eyelids.

Weakness of the limbs, unsteadiness of walking, ataxia.

Muscle paralysis and tendon reflexes.

Disappear. 3. Symptoms of respiratory and reflux failure: dyspnea.

Abrupt, superficial and irregular cyanosis.

Blood pressure drops, pupils are narrowed and then dilated or asymmetrical, speech is impaired, coma, and finally death from respiratory and reflux failure.

The above content reference: People's Health Network - Is it true that you can't eat more puffer fish and salmon?

Encyclopedia - Tetrodotoxin poisoning.

Toxic, just less.

First of all, I would like to tell you that farmed puffer fish are still poisonous, but when the food chain changes, the toxins will be reduced, but the statement that they are almost non-toxic is still not true.

Popular science is as follows:

1. Whether farmed or wild, puffer fish are poisonous. The toxicity of farmed puffer fish decreases due to changes in the food chain, but the toxicity increases during the sexual maturity of puffer fish, so there is also a risk of poisoning when eaten farmed puffer fish.

2. Zhou Guoping, deputy director of the Nanjing Fisheries Research Institute, and Professor Zhao Qingliang of the School of Life Sciences of Nanjing Normal University, said that puffer fish, whether wild or artificially farmed, are poisonous, but the toxicity of artificially farmed puffer fish is dozens of times lower than that of wild ones, which is low toxicity; However, fish eggs, blood, **, eyes, and liver will still be toxic, and fish eggs and liver will still be very toxic.

3. However, poison is not inedible, in fact, there are few people who eat puffer fish and are poisoned every year, and the key is to master the processing and cooking techniques.

Tetrodotoxin (TTX) was first found in puffer fish, and later found to be present in certain vertebrates (e.g., California salamander [1], goby [2], Costa Rican zebra [3]). Subsequently, tetrodotoxin was also found in many invertebrates (e.g., charonia sauliae [4], aijie crab [5], blue-ringed octopus [6], etc.). The issue of TTX became a hot topic.

At least ...... in the Japanese academic foodie circle）

In 1984, Saito et al. cultivated a non-toxic puffer fish using a non-toxic diet [7]. Other similar studies [8-9] have also shown that TTX is most likely accumulated in puffer fish through the food chain. At the same time, researchers have also found that many marine bacteria [10-12], such as Vibrio found in fan crabs [10]), can produce TTX.

At this point, it seems that tetrodotoxin** in puffer fish is due to certain bacteria that accumulate in the body. But in 1990, Masui came out and caused chaos again, and their study showed that there were not enough bacteria in puffer fish to produce such a large amount of tetrodotoxin [13].

Fugu liver is considered to be the most delicious part of pufferfish. Many Japanese aestherapists used arcane techniques to remove their toxicity. However, due to frequent poisoning accidents, Japan's Ministry of Health and Welfare banned puffer fish liver as an ingredient in 1983.

Foodies don't rest on their laurels. If tetrodotoxin comes from the food chain, it can be obtained by isolating marine bacteria from culture. In 2006, Osamu Arakawa's team at Nagasaki University in Japan cultivated more than 5,000 redfin pufferfish, and then proved that the TTX content of these puffer fish was within a safe range (i.e., non-toxic) through [formula] experiments and LC MS testing.

Although the problem of tetrodotoxin has not been thoroughly studied, it has been proven that it is possible to breed non-toxic puffer fish.