Today Xiaobian wants to introduce a small animal - Fushou snail, I believe that the relatives who grow up in the countryside have seen it, if you have not seen it, you should also listen to the adults. Of course, it doesn't matter if you haven't heard of the relatives, please listen to the editor below:
Fushou snail, also known as large bottle snail, apple snail. Native to South America and the Amazon River Basin, it was introduced to china's southeast coastal areas in 1981 (distributed in Guangdong, Guangxi, Jiangxi, Fujian, Hainan, Taiwan, Hunan and other provinces), and has been listed as one of the first invasive alien species in China. Bottle snails are molluscs in the family Bottle snails, the appearance is very similar to the field snails, large individuals, wide eating habits, strong adaptability, fast growth and reproduction, high yield, all over China are farmed. Its meat is edible, but the taste is not good, and it is not loved by people. In addition, it is also the feed for some precious aquatic animals. If a person eats Fushou snail that is not fully heated, it may cause parasites such as Guangzhou tube strongiae to become infected in the human body. After eating raw or incomplete heating of Fushou snail, it can be infected, which can cause headaches, fever, neck stiffness and other symptoms, and in severe cases, it can cause dementia and even death. So dangerous, I don't know if you know it? Do you still dare to eat?
If you want to prevent eating Fushou snail, you must learn to enlarge the move, the first trick: recognize what the morphological characteristics of Fushou snail are.
Individuals are large, each 100 ~ 150g, the largest individual can reach more than 250g, known as a giant field snail. Fushou snail shell is thin and meaty, and the edible part accounts for 48% of the snail's body weight, which is both a delicacy and a high-protein feed.
The entire body of fushou snail is composed of five parts: head, foot, internal organ sac, mantle membrane and shell. The ventral surface of the head is a fleshy foot, the foot surface is wide and thick, and it can crawl on the pond wall and plant stems and leaves. The shells are short and round, large and thin, with a right-handed shell with 4 to 5 spiral layers, mostly yellowish brown or dark brown. There is a membrane-shaped lung sac that can directly breathe oxygen in the air and has the function of assisting breathing. After inflating the lung sac, the snail can float on the surface of the water, and the gas will be discharged and sink rapidly when it encounters interference.
Fushou snail is similar to field snail, but has different shapes, colors, and sizes. The shell color of the Fushou snail is lighter than that of the general field snail, which is yellowish brown, and the field snail is bluish brown; the tail of the field snail is long and pointed, and the tail of the Fushou snail is flat and short; the shape of the snail cover of the field snail is relatively round, and the cover of the Fushou snail is flattened.
It has a spiral-shaped shell, the color varies according to the environment and the age of the snail, has a glossy and several fine longitudinal stripes, and the head and gastropods protrude when crawling. The head has 2 pairs of antennae, the anterior antennae are short, the posterior antennae are long, and the posterior antennae have one eye on each lateral side of the base. The left side of the screw has a thick lung straw. The shell is thick and the shell is 7 cm high.
Life habits of Fushou snail: Fushou snail likes to live in fresh water with fresh water and sufficient bait, and multi-group inhabits the shallow water area by the pond, or adsorbs on the stems and leaves of aquatic plants, or floats on the surface of the water, and can leave the water body for a short time. The most suitable growth water temperature is 25 ~ 32 °C, the growth rate above 35 °C is significantly reduced, the highest critical water temperature for survival is 45 °C, and the lowest critical water temperature is 5 °C. In the vast area south of the Yangtze River, Fushou snails can naturally overwinter.
Growth and reproduction of Fushou snail:
Fushou snails are hermaphrodite, in vivo fertilized, in vitro development of oviparous animals. From March to November every year, the breeding season of Fushou snails is the peak of breeding, of which May to August is the peak of breeding, and the suitable water temperature is 18 °C ~ 30 °C. Fertilization can be laid multiple times, 3 to 5 days after mating, eggs begin to be laid, and at night the female snail climbs to the pond wall, wooden stakes, and stems and leaves of aquatic plants 15 to 40 cm from the water surface to lay eggs. The egg is round, about 2 mm in diameter, the initial spawn is pink to bright red, and the surface of the egg has an inconspicuous layer of white powder. The eggs are adhered to each other into a lump, each egg is laid, 200 to 1000 eggs, 20 to 40 eggs can be laid a year, and the amount of eggs is 30 to 50,000.
The hatching snails fall into the water, swallow plankton, etc. The young snails mature sexually after 3 to 4 months of development, and live in fresh water for a lifetime, except for spawning or migrating in the face of adverse environmental conditions, and in case of drought, they close the shell cover and stand still for up to 3 to 4 months or longer. It should be noted that a female snail has bred more than 325,000 young snails in two generations in one year, which is extremely fertile.
What is the harm of Fushou snail?
Fushouluo was introduced to Taiwan in the 1970s and to Guangdong in 1981 by a Brazilian Chinese. After 1984, Fushou snails have been widely farmed in Guangdong. Due to overculture, coupled with a bad taste, it is released into the wild. Fushou snail has a strong ability to adapt to the environment and reproduces quickly, so it spreads rapidly in rivers, lakes and fields; its large amount of food and a wide variety of food can destroy the growth of food crops, vegetables and aquatic crops, and has become a harmful animal in Guangdong, Guangxi, Fujian, Yunnan, Zhejiang, Shanghai, Jiangsu and other places.
In the vast area south of the Yangtze River, Fushou snails can naturally overwinter, and two generations occur every year. In Luzhai County, Guangxi And other places, the incidence density of Fushou snail in rice fields is as high as 16.95 per square meter; the rate of rice victims is generally 7% to 15%, and the highest is 64%. Fushou snail is heterogeneous, harmful to lotus root, young snails can eat the lotus leaf floating on the surface of the water from the bottom of the leaf, resulting in perforation or lack of engraving of the lotus leaf leaves, and when the leaves are severe, they are eaten with many holes and are difficult to withdraw from the water. Fushou snail also endangers various aquatic plants such as daffodils and orchids, and has become a major pest in the waters of southern China.
In addition, Fushou snail is also an intermediate host of zoonotic parasitic diseases, which is very easy to bring health problems to the surrounding residents. It is estimated that the waters (ponds, lakes, paddy fields, etc.) affected by it in southern China provinces and cities are not less than 100,000 hectares.
The control of Fushou snail is mainly chemical control, supplemented by artificial control, and raising duck snails is one of the biological control methods. The ecological habits of Fushou snail are not well understood and the prevention and control is not effective. In particular, the selected chemical snail killer is highly toxic to water bodies and seriously pollutes water quality; the amount of application is large, the cost is high, and the effect is poor.
Fushou snail can bite off the main tillers and effective tillers of rice, resulting in a reduction in effective panicles and a yield reduction of more than 20%. In addition to eating aquatic plants such as rice, it also spreads diseases such as Guangzhou tube roundworm [1]. People can be infected after eating raw or incomplete heating of Fushou snail, which will cause human eosinophilia meningitis and meningoencephalitis, causing headache, dizziness, fever, neck stiffness, facial nerve paralysis and other symptoms, severe cases will appear paralysis, drowsiness, coma, etc., and even death.
Explanation: [1] Guangzhou strongyloidiasis, also known as eosinophilia meningitis. The disease is a zoonotic parasitic disease that is infected by eating raw or half-raw snail meat containing the larvae of Theocyanta cambilis. Its larvae mainly invade the human central nervous system and manifest as meningeal and encephalitis, meningitis and myelitis, which can kill or maim a person.
Related stories
Two people in Beijing were diagnosed with "Guangzhou pipe roundworm disease" after eating two "delicious dishes" of "spicy Fushou snail" and "cold mix snail meat". The patient had a headache that lasted for two weeks, and when it was severe, the head could not be shaken at all, and the headache was worse when walking, sitting, and turning over, and at the same time, the neck was stiff, the movement was restricted, and there were symptoms such as fever and fatigue. After a detailed examination by hospital experts, the unanimous diagnosis was "Guangzhou tube protodemosis".
According to experts and professors from South China Agricultural University, each Fushou snail contains as many as 3,000 to 6,000 Guangzhou pipe round wire larvae. Mildly infected people will have mild headaches and low-grade fevers, and severe cases will have severe neurological lesions. After diagnosis, treatment is carried out with drugs such as propylthiazole. It is recommended that people who have consumed snails such as Fushou snails should see a doctor as soon as possible if they have abnormal reactions and discomfort.
Lian Ping's relatives, please don't go to the field to catch and eat, but you can kill them, remember not to mistake the Fushou snail as a field snail!