Why can't you eat the egg-laying animal Fushou snail? What's the harm? How to prevent and cure? Attached culture technology

Fushu snail, also known as big apple snail, apple snail, the appearance is very similar to the field snail, the individual is large, eating a wide range of food, strong adaptability, fast growth and reproduction, high yield. Then why can't the snail be eaten? What's the harm? How to prevent and cure? What are the breeding techniques? I learned from Mr. Wang, the owner of Changsha restaurant, that the meat of the snail is edible, but its taste is not good, and eating the underheated snail may cause parasites such as Angiostrongylus cantonensis to infect the human body.

What is the harm of Fushou snail?

1. The large amount of food and a wide variety of food can destroy the growth of food crops, vegetables and aquatic crops.

2. The feeding habits of Fushou snail are miscellaneous and harmful to lotus root. Young snails can gnaw the lotus leaves floating on the water surface from the bottom of the leaves, causing the lotus leaves to be perforated or engraved. In serious cases, the leaves are riddled with holes and difficult to pull out of the water. The snail also harms all kinds of aquatic plants such as daffodils and orchids and has become a major disaster in the waters of southern China.

3. Oncomelania hupensis is also an intermediate host of zoonotic parasitic diseases, which is easy to bring health problems to the surrounding residents.

How to control Oncomelania hupensis?

1. Agricultural measures

① eliminated the source of overwintering snails. The snail is mainly concentrated in the river channel and the low-lying water accumulation in the ditch, so it is necessary to clean up the ditch beside the rice field before spring ploughing, remove silt and weeds, destroy the overwintering place of Oncomelania hupensis, and reduce the survival rate of overwintering snail and the amount of residual snail after winter. At the same time, drugs are used to prevent and cure ditches and low-lying stagnant water.

② blocking transmission: in the downstream area of the re-occurrence area, a barrier net is installed at the entrance of the irrigation canal or at the inlet of the rice field to prevent the snail from entering the field with the water.

③ artificial hunting: during the peak spawning period in spring, combined with field management, the egg blocks are removed from the fields and ditches, taken away from the rice fields to feed ducks or crushed. When drying the field, the adult snails are mainly concentrated in the inlet and drainage and the seedling ditches, and the snails are picked up manually in the morning and afternoon. Artificial removal of egg blocks and picking up snails when combined with farming. When drying the field, the adult snail is mainly concentrated in the inlet and drainage and the seedling field ditch to collect the snail manually, which can also control the damage.

④ artificial trapping: after the paddy field was flooded, 30cm high bamboo slices (wood strips, rape straw) were inserted into the paddy fields to induce Oncomelania hupensis to lay eggs on the bamboo slices (wood strips and straw). The egg blocks were removed and destroyed every 2 to 3 days. The quantity of 3080 bamboo slices (wood strips and straw) per mu should be planted near the edge of the field to facilitate the removal of egg blocks.

2. Biological control

Biological control is mainly adopted to raise ducks and feed on snails. The duck release time is from 7 to 10 days after rice transplanting to the late booting stage of rice, and the flocks of ducks (15 to 30 ducks per mu) are released every morning and at 5: 00 or 6: 00 in the afternoon to peck at young snails in rice fields and canals to reduce the number of snails and reduce damage.

3. Chemical control

The control index of ①: 1 / m ~ 2 in seedling stage, 1 / m ~ 2 in field edge, 3 / m ~ 4 in tillering stage, 1 / m ~ 2 in egg mass / m ~ 2.

② control agents: 10% snail snail granule, 6% Mida molluscicidal granule, 50% molluscicidal ethanolamine salt wettable powder, 70% spirosemide wettable powder, 45% tin triphenylacetate wettable powder and so on.

③ application period: two times of application: 1. 2 leaves and 1 heart stage of rice in seedling field. 2. Apply pesticide when transplanting. If the snail damage is serious, the pesticide should be applied once every 10 days.

④ application method: the dosage of 10% snail cochlea granule is about 400-500g per mu, evenly spread in the field or mixed with fine soil 5~10kg. The dosage of 6% Mida molluscicide granule is about 400g / mu, which is evenly spread in the field or mixed with fine soil 5~10kg. 70% spirosemide ethanolamine salt wettable powder is sprayed with 60 grams of water and 20 kilograms of water per mu.

4. Matters needing attention: the water layer in the field is 1cm to 3cm and the water is preserved for 7 days. If it rains heavily within 24 hours after application, it needs to be replenished once. Molluscicide is toxic to fish. 7 days after application, the field water can not be discharged into the fish pond, and the stocking of ducks is prohibited.

Attached: culture technology of Oncomelania hupensis

Oncomelania hupensis is the feed of some precious aquatic animals. Breeding Oncomelania hupensis can provide active erbium material to aquatic animals.

1. Choose a suitable culture environment. Fushou snail requires fresh water quality, so the aquaculture water surface should be convenient for drainage and irrigation, and the water depth should be 0.3-lm. The area is as large as 3mu and several square meters as small as possible. Aquatic plants should be planted on the aquaculture surface to provide snails with an environment for summer shelter and light shelter, as well as natural feed. Generally, the density of aquatic plants can account for 30% of the water surface, 35% of the water surface. In order to facilitate baiting and management, bamboo poles can be used to block the water surface into several areas. More bamboo and wood strips are inserted into the water surface of the snail pond to provide a spawning place for female snails. Carp, tilapia and soft-shelled turtle all eat young snails and can put in some silver carp species; therefore, drugs are used to kill the snails before releasing them. The discharge and intake should block the tight mesh to prevent the snail from drifting away with the water.

2. Stocking of snails. Stocking density should be determined according to water source, bait, management conditions, seedling size and planned harvest specifications. Generally speaking, there are about 5000 newly hatched snails per square meter, 2000 snails can be sparse when they grow to 3G in 20 days, and then they can be reduced as the snails grow up. The size of the snail body is different, and the feeding capacity is also different. where there are conditions, the snails of different specifications should be raised separately in order to feed evenly and grow synchronously.

3. Feed. The total daily feeding amount is generally about 10% of the total snail weight, in which the concentrate is more than 0.5% of the total snail weight, and the green feed is determined to meet its feeding needs. Feed is required to be fresh without spoilage. When the green feed and concentrate feed are fed at the same time, the green feed can be fed first, and then the concentrate feed can be fed after it is basically eaten up. Fushou snail avoid direct light, sink to the bottom of the water or hide in the dark during the day, and float to the surface to feed at night. Therefore, baiting should be carried out in the evening.

4. Water quality management. The snail has a large amount of food and feces, and the pond water is prone to decay and deterioration, so the management of water quality is very important. In order to ensure that the snail can grow continuously and rapidly, the water should be changed frequently to keep the water fresh. When the water quality deteriorates, the snail growth slows down and even dies. Where there are conditions, the effect of keeping micro-flow in aquaculture waters is the best. Still water culture usually takes about 7 days to change water.

5. The eggs are incubated centrally. The method is to 20-30cm on the surface of the incubator (or snail breeding pond), set up a bamboo foil (with many small holes), and lay the egg block on the foil. The egg block is covered with shade (such as branches, etc.) to prevent exposure to the hot sun. After hatching, the young snails fall into the water and begin to feed and grow.

6. elimination of pests and prevention of escape. Rodents and weasels do serious harm to Oncomelania hupensis. Rodents are especially good at eating snails near the water, so measures should be taken to prevent them. At the same time, the firmness of the tight fence set up at the water inlet should be checked at any time to prevent the snail from walking with the water.