I. Habits of Oncomelania Oncomelania likes to inhabit water environments rich in humus in sediments, such as lakes, ponds, swamps or slow-flowing rivers. They often feed on microorganisms and humus in soil, phytoplankton in water, aquatic plant seedlings and moss, and also like to eat artificial feeds, such as fruits and vegetables, vegetable leaves, rice bran, wheat bran, soybean meal (cakes) and various animal scraps. Oncomelania is cold-resistant and afraid of heat. The suitable temperature for its life is 20℃ ~ 28℃. When the water temperature is lower than 10℃ or higher than 30℃, stop eating and drill into soil and grass to avoid cold and summer. When the water temperature exceeds 40℃, the snail is scalded to death.
Second, the reproduction of stone snails. Stone snails are hermaphroditic. The male and female identification method of stone snail is mainly based on the shape of its right antenna. The right antenna of the male snail bends inward to the right (the bent part is the male genitalia). In addition, the female snail is big and round, and the male snail is small and long.
Oncomelania hupehensis is an oviparous animal, and its reproduction mode is unique. The embryonic development and larval development of Oncomelania hupensis are completed in the mother body. It takes about a year for a fertilized egg to give birth to a small snail. Oncomelania hupensis lays eggs in batches and begins to breed in March-April every year. While producing young snails, the male and female parents mate and fertilize, and at the same time, the young snails to be produced next year are propagated in the mother. A female snail produces about 100 to 150 young snails a year.
Third, artificial breeding.
1. Oncomelania hupensis has strong adaptability and few diseases. As long as a large number of pesticides and fertilizers are avoided, many flat rivers, streams, potholes, paddy fields, ponds and other ordinary water bodies in rural areas can be stocked. If you dig a special pond for feeding, choose a place with convenient water source and humus soil to build a pond (if the soil is not suitable, it is best to apply mixed compost to improve it first). Keep the thickness of sediment at 10cm ~ 15cm, with unlimited area. If it is an open water body, a small amount of duckweed and water lily can be planted on the water surface, some vines and melons and vegetables can be planted around the pond for shade, and snails such as bamboo tails, branches or stones and grass can be arranged in the water for hidden habitat.
The day before 10 snail release, apply quicklime to the whole pond according to the dosage of 50 kg ~ 100 kg per mu to remove wild fish, shrimp and other miscellaneous snails. After 3-4 days, organic fertilizer and breeding bait organisms are piled up in the water for snails to eat.
2. It is best to complete the stocking of seed snails in the early stage of snail reproduction. Source of snail species: one is field collection, and the other is market collection. Choose fresh snails, light brown in color, thin and complete in shell, and dim in dome. Generally speaking, putting 0. 1 kg ~ 0.5 kg of seed snails into the natural extensive water body per square meter can increase the number of species by 2 ~ 3 times in the intensive culture pond. The cultured Oncomelania hupensis can be raised alone, interplanted with some silver carp and bighead carp varieties, or mixed culture of Oncomelania hupensis and loach.
3. Feeding and management of extensive farming methods in natural water bodies, only by maintaining the fertility of water bodies and regularly applying appropriate amounts of manure, chicken manure, cow manure, pig manure or straw can meet the growth needs of Oncomelania hupensis. In the case of high-density intensive farming, artificial bait must be put in. Oncomelania snails don't need much nutrition. Rice bran, wheat bran and soybean meal were simply mixed at the ratio of 60%, 25% and 15% to make high-quality feed for Oncomelania hupensis.
According to the feeding situation of Oncomelania hupensis and climatic conditions, Oncomelania hupensis has a strong appetite at a suitable temperature (that is, 20℃ ~ 28℃), and can be fed once every two days, and the feeding amount is 2% ~ 3% of the body weight each time. When the water temperature is in the range of 15℃ ~ 20℃ and 28℃ ~ 30℃, it is fed twice a week, and the dosage is about 1% each time. When the temperature is lower than 15℃ or higher than 30℃, it is less than or equal to zero.
Four, it is forbidden to flow into the water polluted by pesticides and fertilizers in daily management; Prevent the invasion of enemies such as ducks, snakes, rats and birds; Remove weeds and roots in water in time. Usually in the form of micro-running water, keep the water level at about 30 cm. In high temperature season, the water flow should be increased, and the temperature rise should be controlled to ensure sufficient dissolved oxygen in the water. Oncomelania snails hibernate in the soil when the weather is cold. At this time, change the water 1 ~ 2 times a week, and sprinkle some chopped straw on the water body to help snails overwinter.
Verb (abbreviation of verb) Harvest and transportation After a year of careful breeding, the released young snails can reach 10g ~ 20g, and the hatched young snails can reach the specifications of more than 5g that year.
When harvesting Oncomelania hupensis, we should adopt the method of catching large snails and listing small snails in batches, selectively take adult snails, leave young snails and leave some female snails, so that natural replanting can be realized, and there is no need to release seedlings in the future. According to their living habits, in the hot season of summer and autumn, they choose to pick up bamboo branches and grass stems rotating on the shore or in the water body in the morning and evening; In winter and spring, choose sunny noon to pick. In addition, snails can also be caught in the lower pool or picked up in the drainage dry pool to harvest. The transportation of stone snails is very simple, and they can be packed in ordinary bamboo baskets and wooden barrels. , or packed in woven bags. As long as the snail stays wet during transportation, it can avoid exposure to the sun.