The "little devil" in the water is trending again! Why are invasive golden apple snails more deadly than native snails?

Recently, golden apple snails have become a hot topic again. It was revealed that many merchants on the market use golden apple snails instead of field snails for sale, which scared many consumers. It is said that there are 3,000-6,000 parasites in a golden apple snail, and eating it may cause serious parasitic diseases. Is this true? What kind of snail is the golden apple snail? How to distinguish it from the field snail? Today, let's talk about the golden apple snail.

Pomacea canaliculata is the trade name of the giant bottle snail, native to South America. It was first introduced to China as an economic aquaculture species in the 1980s, and great efforts were made to promote it at that time. Pomacea canaliculata grows fast, has strong disease resistance, is not picky about food, and has a large yield. From these aspects, it is indeed a good economic species. However, Pomacea canaliculata has a fatal flaw, which is that it is not very delicious. Compared with our native edible snails, such as the Chinese round field snail (Cipangopaludina), the snail meat has a very crisp taste, while the snail meat of Pomacea canaliculata does not have this crisp feeling. In addition, if the heat is not well controlled during cooking, the snail meat can easily become chewy, which has led to a large number of unsalable Pomacea canaliculata. Finally, farmers dumped the unsold snails into the wild. Now, a very serious invasive population has formed in many provinces in southern China. Now, Pomacea canaliculata has become an alien invasive species in many waters in southern my country, seriously squeezing the living space of native snails. Although some relevant departments and units have promoted free-range ducks to prey on snail eggs and artificially catch golden apple snails, the results have been minimal so far. There are even records of golden apple snails breeding in northern areas such as Beijing. So we should not easily release or abandon our pets or other creatures into the wild.

It is very easy to distinguish between the Golden Apple Snail and the Round Pool Snail. The Golden Apple Snail belongs to the Bottle Snail family. Its lid is much larger than that of the Round Pool Snail, and the spiral tower of its shell (that is, the small tail on the shell) is very short. The whole shell looks very flat, while the spiral tower of the Round Pool Snail is very tall, like a towering pagoda.

The golden apple snail is the intermediate host of many parasites, including the Guangzhou roundworm and the spiny fluke. Among them, the Guangzhou roundworm is the most famous. Infection with the Guangzhou roundworm can cause severe headaches, accompanied by fever, nausea, vomiting, and may cause meningitis. If not treated in time, it may lead to death.

In 2006, there was a very popular restaurant in Beijing, which was right near my home. At that time, dozens of people were infected due to the use of undercooked golden apple snails. This case shocked the whole country at the time, and the restaurant's business never recovered. The golden apple snail also made everyone afraid of snails.

In theory, wild aquatic animals will carry some parasites, viruses, bacteria and other pathogens to a greater or lesser extent. If we cook them thoroughly, most of the pathogens they carry will be killed. So there is a saying: thoroughly cooked food is safe and worry-free. This is exactly the case.

Why is it easy to get parasitic diseases by eating golden apple snails? It is still related to the meat quality of golden apple snails. As we said before, if the meat of golden apple snails is overcooked, that is, the fire is too high, it will become difficult to chew and the taste will become very bad. Therefore, many chefs will choose to stir-fry over high heat or blanch in hot water when cooking golden apple snail dishes. The snail meat is easily not fully cooked, and the pathogens are not completely killed, so people will be infected if they eat it. There is no such concern when cooking the round field snails native to my country, so it is relatively safer.

When we eat various aquatic products, it is best not to eat them raw. They must be fully cooked before eating, especially various freshwater aquatic products. Now many ocean-going fishing vessels will freeze the fish at ultra-low temperatures to kill the parasites in their bodies after catching them. This kind of food is relatively safe, but eating it raw may have a higher risk of allergies for some people, especially those with sensitive constitutions, so try to avoid eating it raw.

To ensure food safety, the most important thing is to go to regular markets or supermarkets to buy food that meets food hygiene standards, including aquatic products, meat, mushrooms, etc. Try not to pick, fish, or catch wild animals and plants for consumption, which is not only bad for our health, but may also violate the law. At the same time, when cooking, make sure to cook the food thoroughly to ensure safety.

This article is a work supported by the Science Popularization China Creation Cultivation Program

Author: Li Weiyang Popular Science Creator

Reviewer: Zhang Na, Associate Researcher, School of Public Health, Peking University

Produced by: China Association for Science and Technology Department of Science Popularization

Producer: China Science and Technology Press Co., Ltd., Beijing Zhongke Xinghe Culture Media Co., Ltd.