Fish is a delicious dish, rich in nutrients. However, there are some fish species that carry many toxins that can cause poisoning to people who eat them, even death. Consumers need to know how to distinguish them to avoid them, and absolutely must not eat them.

1. Grass carp bile

Grass carp is a familiar fish on Vietnamese dinner tables, but grass carp bile is very toxic because it contains alcohol that causes bleeding and damage to internal organs, especially the kidney tubules. The larger the fish, the higher the toxicity.

According to the Department of Food Safety - Ministry of Health, there is currently a phenomenon of people using grass carp bile to treat many diseases such as aches and pains, decreased vision, asthma, hives... by swallowing it directly or mixing the gallbladder with water, alcohol or honey. This directly affects the health and life of the user. In recent years, Vietnam has recorded cases of poisoning and death due to the use of grass carp bile.

2. Puffer fish

Puffer fish contain tetrodotoxin (C11H17O8N3), a neurotoxin, very toxic, causing high mortality. In particular, tetrodotoxin is soluble in water, not destroyed by heat, cooked or dried, the toxin still exists. This fish is known to be extremely delicious, but it contains a highly toxic substance that can cause death if processed incorrectly.

People who eat puffer fish containing tetrodotoxin will experience itching in the mouth, numbness of the lips and tongue, and discomfort after 5 minutes to 3 or 4 hours. Then they feel tired, dizzy, lightheaded, feel like their chest is constricted, sweat, drool, foam at the mouth, difficulty speaking, difficulty swallowing, red face, abdominal pain, nausea, vomiting, tremors, stiff jaw, stiff tongue, weakness of lower limbs, constricted pupils, and paralysis of eye movement. Severe cases include paralysis of the whole body, the body becomes limp, the limbs lose the ability to move, the skin turns purple, the temperature and blood pressure drop, difficulty breathing, and eventually respiratory muscle paralysis, cardiovascular collapse, and death. The mortality rate is very high (60%) if emergency treatment is delayed.

3. Clouded goby

One of the other types of fish that contains highly toxic substances is the clouded goby. In our country, clouded goby is concentrated in the coastal provinces of the Central region. According to scientists, clouded goby contains the toxin tetrodotoxin, similar to the toxin of puffer fish.

According to the Department of Food Safety, these poisonous seafood species can harm humans in two main ways: through the digestive tract due to dishes made from fish and seafood and through the animal's self-defense reaction when we accidentally touch them, are bitten, stung, or shot with poisonous arrows.

4. Swordfish

Swordfish is a marine fish that contains high levels of mercury. If you abuse eating too much swordfish, it will increase the risk of methylmercury poisoning. Therefore, you should not eat a lot of this type of fish or you will easily get sick, especially cancer.

5. Shark

Sharks are also on the list of fish that should not be eaten because they not only contain a large amount of mercury but are also poisonous fish that live by eating other fish to survive.

Therefore, it can be said that sharks will absorb a lot of toxins from other fish into their bodies.