The most poisonous fish in the world is the so-called puffer fish. It’s liver and other parts of it’s body contain a substance called tetrodotoxin, which can paralyze the respiratory muscles of any living creature and lead to its death. Despite the dangers, many Asian chefs include it in their menu dishes with the addition of its non-toxic organs. True, for cooking, captive-grown individuals with a low content of poison in the body are used. By comparing the fish that grew up in captivity, scientists were able to find out why they needed poison.
The reduced amount of poison in the body of captive-grown puffer fish is explained by the fact that they do not produce it on their own, but receive it from bacteria living inside them. The bacteria that produce tetrodotoxin in large numbers live only in the natural habitat of puffer fish, so individuals grown in aquariums cannot boast a large amount of poison. It is believed that a reduced amount of toxins worsens the taste of “incubator” fish and also negatively affects their health.
The most dangerous poison in the world
The latter fact was proved by scientists from the Japanese universities of Kitasato and Nagasaki, who published the results of their research in a scientific journal. Toxicon. Researchers took two aquariums with puffer fish, one of which was supplemented with tetrodotoxin content over the course of a month. By comparing the health status of individuals from two different aquariums, they were able to find out how the toxic substance affects fish organisms and why they need it.
In the course of observations, scientists found that fish fed with tetrodotoxin content were 24% longer than the individuals from the second aquarium. It follows that the toxic substance contributes to the growth and proper development of puffer fish. It also turned out that fish with a sufficient level of tetrodotoxin have four times less cortisol, a hormone that promotes the development of stress. Therefore, a toxic substance is a means of protection against stress.
How exactly tetrodotoxin controls the growth of puffer fish and affects the level of their stress is unknown to researchers. It may well be that they will be able to answer this question in the course of other scientific works. As for the poor taste of captive-raised fish, maybe the meat loses its taste just because of increased stress. In addition, scientists noticed that puffer aquarium fish stand out with particular aggression and attack each other, causing wounds. This, too, may well impair the taste of their meat.
Whether the poison itself affects the taste of meat is unknown. Be that as it may, cooks completely clean the fish of poisonous parts of the body, so that tetrodotoxin is not contained in dishes. For cooking puffer fish dishes, restaurant employees undergo special training for at least three years. During this time, cooks learn to properly cut off the organs of the fish, the most dangerous of which is the liver.
As a rule, death due to poisoning with this poison occurs due to paralysis of the respiratory muscles, but scientists believe that with the right dosage, it can serve as an excellent analgesic with a lasting effect. It seems that in the future, an anesthetic based on puffer venom will actually appear – researchers from the Boston Children’s Hospital have figured out how to control its dose so that it does no harm.
Previously, medical professionals have already tried to use fugu venom to eliminate severe pain in leprosy and inoperable tumor diseases. They really managed to establish safe doses of the toxin so that it effectively eliminates pain and does not harm the body of patients, but because of the potential danger and the availability of analogues in the form of novocaine, its use was suspended.
Despite this, work on the creation of an anesthetic based on tetrodotoxin does not stop. Fugu venom is interesting because its molecules effectively clog nerve fibers and block their impulses – scientists can very well create a technology that controls its amount and provides a safe anesthetic effect lasting several days.
Tetrodotoxin turned into anesthetic
A major breakthrough in this matter was made by staff from the Boston Children’s Hospital, led by Professor Daniel Cohan. To control the rate of release of the poison to a specific point in the body, they mixed it with a biodegradable polymer, and subsequently controlled release times provided a long-lasting anesthetic effect. The experiment was conducted on laboratory rats.
The lesson we learned is that with our previous delivery systems, the anesthetic was spreading too quickly, which could lead to poisoning. This time we injected such an amount of tetrodotoxin that it would be enough to kill the rat several times, but thanks to the controlled introduction, the animal didn’t even feel it, ”Daniel Cohane shared.
Even though scientists used a rather large amount of poison, it was still less than in previous attempts. It was possible to maintain the effectiveness of the substance while reducing its dose due to the addition of a chemical penetration enhancer – tetrodotoxin penetrated the tissues more easily and acted as concentrated as possible.
Symptoms of tetrodotoxin poisoning
If, in the event of an error, tetrodotoxin enters the human body too quickly, it will immediately lead to poisoning and, most likely, to death. Symptoms occur within 10-15 minutes, and include itching, excessive salivation, vomiting, loss of skin sensitivity and, ultimately, paralysis of the respiratory system.
The first case of tetrodotoxin poisoning was recorded in 1774 – the case was described in the book Journey to the South Pole and Around the World by the English sailor James Cook. The poisoning occurred in New Caledonia when he and his companions tried a dish of local fish and felt severe weakness and numbness. Fortunately, they received a small dose of toxin and got better after vomiting, but the pig, who was given the rest of the dish, died.
Puffer fish dish
However, puffer fish meat is sold in some Japanese stores, which is extremely dangerous for inexperienced cooks. In 2018, an alarm was announced in the city of Gamagori, as in one supermarket they managed to sell fish meat without an extracted liver.