Snail is a mollusk that lives on land. It stays in the daytime and comes out at night, preferring to be dark and damp, fearing light and heat, and mostly inhabiting the environment of overgrown weeds, lush trees, lush crops, loose soil, rich humus, haystacks, caves, fallen leaves of branches, stones and so on. When the ground is dry or in bad conditions, they often climb to the trunk, axil or back of leaves to hide and sleep. Its suitable growth temperature is 7 ~ 24℃, air humidity is 75 ~ 90%, and pH value is 5 ~ 7. When the situation is serious, the soft part can be drilled into the topsoil for 250 mm to sleep, or the milky opaque mucus film can be secreted to close the shell mouth. Snails come out after 1 1 at night and have strong tolerance to cold, drought and hunger. But it can't adapt to various odorous chemicals such as lime, firewood ash and coal tar.
Snails are omnivores. Most of the young snails come from saprophytes and mainly feed on saprophytes; Oncomelania snails are mainly green plants, and feed on the roots, stems, leaves, flowers and fruits of various plants, especially the buds and succulents of plants, as well as all kinds of waste paper, pig manure and plant residues. Eat each other when you are hungry.
Snails lay eggs 2-3 times every two years, and the peak period is June-August every year. They lay 200-300 eggs twice, all in loose soil 2-3 mm deep-or under fallen leaves and stones. Stop eating when laying eggs, and most of them dive into the soil first. After a period of time, the head and feet shrink to the mouth of the shell, and the feet are flat and stick to the ground or stone. Eggs are oval, with calcareous shells, milky white or light blue yellow. Eggs hatch into larvae after about 5 ~ 15 days in the soil. The artificial hatching methods of eggs include covering soil, covering cloth, covering pots, drying eggs, isolating soil and keeping warm. Generally, the temperature is 20 ~ 30℃ and the humidity is kept, and the young snails can hatch in about 10 days.
For indoor artificial breeding of snails, it is advisable to choose a leeward open space, and build a feeding shed of 20 meters, 3 meters wide and 2 meters high with bamboo or steel bars, and cover the shed with plastic film. It can also be used to cultivate vegetables in plastic soil shed, old glass greenhouse or soil hotbed. For indoor seedbed cultivation, it is advisable to use cement and steel bars to cast boards with a length of 1 m and a width of 0.8 m, and build them into 3-4 layers with a height of 0.6-0.8 m. Then, screen windows are used to separate each layer, and humus soil with a thickness of 1.5cm is spread on the two layers, so that 30 snails can be placed in each square meter, and 1 is carried out every day. Indoor wooden box breeding should be done in boxes with a length of about 90cm, a width of 45cm and a height of 40cm. Spread humus soil with a thickness of 10 ~ 15 cm in the box and put vegetable leaves. Put 20 ~ 30 snails in two boxes and water them every two nights to make the inner walls of the boxes moist.
Snails should be fed once a night. Vegetables, crops, green manure crops, weeds, roots, stems, leaves, flowers, fruits, peels, residues and waste paper can all be used, and some concentrated feed, protein feed and mineral feed can also be added. It can also be fed once every two days. Snails can eat leftover rice and humus. Keep sprinkling water, so that the field humidity is 15 ~ 27%, the pH is 5 ~ 7, and the air humidity is 75 ~ 90%. When the young snails hatched in that year, they reached five snail layers in five months, weighing more than 50 grams, and the largest reached about 90 grams. The harm of natural enemies such as chickens, ducks, sparrows, pigeons and mice should be prevented in breeding.
The key point of culture temperature is 16 ~ 40℃, preferably 25℃, generally high or low. Earthworm fire must be used for heating, and it should be prepared all year round, especially in late spring and early summer, to prevent sudden cooling. Conditional heating is the best, not furnace heating. Humidity. The soil surface humidity of the feeding soil should be kept at 25% ~ 35%, and the relative humidity of the air should be 85% ~ 90% to make it moist, and the top should be covered with plastic sheets for moisture control and moisturizing. In order to prevent dry air and cold air from blowing in directly, double doors, hanging cloth and wind deflector should be adopted at the entrance. Resolutely control the odor from entering the breeding ground. Feeding soil must be controlled at pH 6.5 ~ 7.5, and sandy soil polluted by pesticides and chemicals shall not be used. Breeding containers must have good water permeability and air permeability. Don't be exposed to strong light when you are not working, preferably in the dark. Lighting with 15W red bulb at night can stimulate spawning. The hatching of eggs. The key to the success or failure of snail farming lies in the hatching of eggs. Indoor temperature is controlled at 20 ~ 25℃, air humidity is controlled at 90% ~ 95%, and soil surface humidity is controlled at 25% ~ 30%. Improve the method of egg collection and incubation, and adopt the 60-day snail cultivation method. This method can greatly improve the reproductive efficiency of snails, and the general hatching rate is above 95%. The feeding of young snails is related to the success or failure of the rapid development of snail quantity and output, especially the control of temperature and humidity. Generally, the temperature should be controlled between 25 ~ 30℃, the water content of the soil is 30% ~ 35%, and the relative humidity of the air is 80% ~ 90%. Eat more fresh and juicy feed, supplemented by calcium supplements. 1 ~ 3-month-old snails should be humidified in the pond without splashing water. Spray with a sprayer, preferably warm water. If dead snails are found, clear them in time. Always mix earthworms and snails to clean up feces. It is best to kill two birds with one stone. In order to prevent the invasion of natural enemies and kill rats and ants, regular spraying of trichlorfon solution of11000 can effectively kill the largest natural enemy mite of Oncomelania hupensis, and regular disinfection of snail breeding grounds with peracetic acid diluent can kill pathogenic microorganisms. The feed formula with the lowest cost and the best effect: 50% rice bran, 40% shells, 8% yeast powder and 2% others. Feeding and management
Feeding mode
Generally divided into outdoor open and indoor closed two kinds.
Outdoor opening includes ditch type, shed type and courtyard type. To make it grow and breed in the protected area, similar to natural conditions. Indoor closed culture can use plastic pots, pottery pots, wooden boxes, cement pools, cylinders, barrels, cans and so on. Covered with gauze, sealed with wet cloth and film to keep warm and moist and prevent rodents. Indoor closed breeding is convenient for the adjustment of temperature and humidity, and with sufficient feed, it can not only relieve the hibernation of snails, but also achieve the purpose of breeding in winter. Indoor culture is best to use plastic film to seal the surroundings and keep the temperature and humidity.
Preparation of feeding soil
1, compound vegetable garden soil
30% of unpolluted sandy soil, 30% of pastoral soil, 20% of yellow sand, 15% of cinder ash and 5% of stone powder are mixed and crushed, disinfected and sterilized by sun exposure for 3-5 days, sieved, and then water is added to make the humidity around 40%, that is, it is kneaded into a ball at one time and dispersed at one blow. The soil thickness in the basin is: adult snail 7 cm, adult snail 65,438+00 cm, young snail 3 cm, and it is fed 65,438+0 times from October to February.
2. Sponge substitution method
Lay 1 5 cm thick sponge on the bottom of pools and boxes. , and keep 4 times its own weight of water. Clean up the leftover food every day, and clean up the feces every 3 days 1 time.
Feeding method
1 month-old young snails should be fed with fresh and tender leaves, and the concentrated feed should be boiled and softened on the leaves, once a day 1 time. The optimum temperature should be controlled at 25℃ ~ 30℃, and the temperature difference between day and night should not be large. Don't spray young snails directly when spraying water. In addition to green materials, more concentrated materials, trace elements and additives should be added to raise snails. The daily food intake is 7% ~ 10% of the snail's body weight. Feed should be put into a food rack or basin to clean up the residue. The stocking density varies from dense to sparse with the increase of individuals, ranging from 400 to 200 per square meter. A 60×30×25 cm feeding box can feed 100 pigs. After 5 ~ 6 months, the shell can be harvested when it is 4 cm high and weighs more than 40 grams.
Overwintering management
Hibernation can be lifted under the condition of artificially controlling temperature and humidity. If the feeding conditions cannot be met, when the temperature drops to about 65438 05℃, heat preservation should be carried out according to local conditions. If it is transferred indoors, the feeding soil is thickened to 25 cm, and the outer cotton wool is insulated.
Brief history of aquaculture
Snails have a long history of food and medicine in China. Snails were recorded in detail in Erya's "Free Fish" more than 2,000 years ago. In the 6th century BC, Tao Hongjing's Records of Famous Doctors recorded an example of snail treatment. In A.D. 1774, Li Shizhen of Ming Dynasty described the morphology and medicinal value of snails in detail in Compendium of Materia Medica. Since the 20th century, many scientists have made great contributions to the study of snails, especially the cultivation and application of snails, but no breakthrough has been made. Until the 1980s, the snail production and export volume in Chinese mainland were still very small, and the export volume was not as high as that in Taiwan Province Province110. However, since the late 1980s, when snails were comprehensively analyzed and tested, it was found that they contained 20 kinds of amino acids, more than 30 kinds of enzymes and hemagglutinin. After truly understanding the value and function of snails to human beings, the snail breeding industry has developed vigorously and gradually become a thriving household sideline in urban and rural areas of China.
Up to now, there are more than 20 provinces and cities such as Hebei, Guangdong, Fujian, Shanghai, Zhejiang, Hubei, Hainan, Jiangsu, Henan, Shandong, Hunan, Sichuan, Liaoning, Inner Mongolia and Gansu. There has been an upsurge of artificial breeding of snails, and it is developing towards scale and industrialization. Snail farming in China is catching up with the advanced world level. After years of development, the main snail breeding area in mainland China is located in Jiaxing City, Zhejiang Province, which is the hometown of snails. According to the data, there are three enterprises in Jiaxing (Yuxin Jiangnan Snail Breeding Base in Nanhu District of Jiaxing City, Jiaxing Hongfu Snail Breeding Co., Ltd. and Jiaxing Qianfu Food Co., Ltd.), which not only play the role of leading enterprises in the local area, but even rank among the best in the country.
Before the birth of white jade snail, many countries mainly raised brown cloud agate snail, because brown cloud agate snail has fast reproduction, strong disease resistance, easy feeding and the most abundant nutrition. Since the birth of white jade snail, many countries have introduced it, because it not only has all the advantages of brown cloud agate snail, but also tastes as delicious as jade. As a result, white jade snails swept the world.
The development of white jade snails in China has accelerated the reproduction and development of white jade snails. In a short time, with the joint efforts of many experts and scholars, we not only found out the living habits and reproductive laws of white jade snails, but also comprehensively tested the nutritional components of white jade snails, and developed a series of snail products according to their nutritional values, which were exported to Southeast Asia, Europe and the United States. Therefore, the breeding, development and utilization of snails can be said to be both a traditional and ancient project and an emerging high-tech project.
The research on snails abroad was later than that in China. Scholars from some European and American countries began to study snails from18th century to19th century, but their development and utilization were ahead of China. In recent years, many developing countries have used their own resources to accelerate the development of snail farming and processing industry, and made it an important export-oriented foreign exchange earning project.
Snails are rich in nutrition. The content of protein, coumarin, alkaloid, organic acid and other elements in snail meat is higher than that in soft-shelled turtle, pork and all egg foods, especially in protein, which ranks first among animals in the world. Most of its biochemical indexes are much higher than those of spirulina, and it is known as healthy food in 2 1 century. Snails are high in protein, calcium, fat and cholesterol, which are very beneficial to human health. There are more than 20 kinds of amino acids and more than 30 kinds of enzymes in their bodies, which are most needed by people but difficult to ingest from other foods. The lectin extracted from snail protein gland has great application value in blood research. The price per gram of lectin in the international market far exceeds the price of gold, so snails are known as "soft gold".
In addition, snail enzyme extracted from snails is also an important raw material for many industries, such as medicine, biology, textile, cosmetics, wine making and so on. Therefore, the commercial value of breeding snails is very considerable.
Snail is a kind of terrestrial mollusk. The common species are homotype snail, African snail, snail, Chinese white jade snail, wild agate snail, scattered snail, bright snail, brown cloud agate snail, covered snail and apple snail. Their living habits and preventive methods are similar. Snails are not all pests.
Snails, like slugs, have long flat feet in their bellies. They move forward by muscle contraction, secrete mucus when they move forward, and glow when they dry. We can do an interesting observation experiment to measure the crawling speed of snails: put a snail on the dry ground and it moves 9 ~13 cm per minute; When climbing to the shady ground, the speed slows down and moves 6 ~ 8 cm per minute; When climbing to the ground with thin water layer, the speed is accelerated and it slides 25 ~ 30 cm per minute. Some western countries hold snail races every year. 1985, Spain held a snail race, in which 68 snails from 8 countries participated. In the competition, a Spanish snail won the championship, and it ran out of 124 cm in 5 minutes.
Harm and prevention
Snails of the same type will take citrus fruit trees as their hosts, and citrus leaves are often eaten by them, and the cortex of branches is often eaten by them, and citrus fruits form pits after eating. Its host plants include saplings, vegetables and flowers.
Snails are harmful to soybean seedlings, causing damage to leaves and stems, delaying the development of stiff seedlings and reducing the seedling rate. In the worst case, all the bean seedlings are eaten up, resulting in no seedlings. Comprehensive measures should be taken to control snails in soybean fields.
Destroy into a snail
In late spring and early summer, especially before the peak of snail reproduction comes in May and June, snails should be eliminated in time. First, chickens and ducks feed snails, and pay attention when not using pesticides. The second is to pick up snails manually. When working in the field, snails are picked up, or they are lured by grass and vegetables, or they are specially picked up manually. This can get twice the result with half the effort
Chemical control
In order to protect the emergence of soybean, when the population of Oncomelania hupensis is large and is about to enter the initial stage of damage, chemical agents are used to kill snails. 300 g paraformaldehyde, 50 g sucrose, 300 g 5% calcium arsenate and 400 g rice bran (first fried in a pot) are mixed into soybean-sized particles; Use 0.5 ~ 0.6 kg of 6% Mida molluscicide or 3% Miwoling granules 1.5 ~ 3 kg per mu, mix with 10 ~ 15 kg of fine soil and scatter in the field. Ditches and wetlands that snails like to inhabit should be properly replanted to minimize the harm of snails.
weakness
Salt reacts on the surface of snails. Because there is a layer of mucus on the surface of snails (except the shell), it is beneficial to the movement of snails and skin-assisted breathing. When you sprinkle salt, the snail's movement and breathing ability are reduced. Mucus seeps into the body, causing the snail's body to shrink and the cells to lack water. At this time, the snail looks dry, but it will never turn into water.
Clean countryside
After harvesting crops or vegetables in summer, weeds in fields, dikes and ditches should be eradicated in time, and furrows should be opened to reduce humidity, and intertillage should be used to turn over the soil, which will worsen the growth and reproduction environment of Oncomelania snails.