Oncomelania hupensis lays eggs in batches and begins to breed in March-April every year. Male and female parents mate and fertilize at the same time, and at the same time, young snails to be produced in the next year are bred in the mother. A female snail produces about 100- 150 young snails a year.
Question 2: How do screws reproduce offspring? Parent snails for reproduction can be collected in paddy fields, ponds or ditches. The selection criteria for breeding parent snails are: light color, thin shell, round body, large body, no damage to the shell, complete cover of the shell mouth and so on. The female snail body is large and round, and the left and right antennae of the head are the same size and extend forward; The male snail is small and long, the right antenna of the head is thicker and shorter than the left antenna, and the end is bent to the right inside, and the bent part is the genitals. 10 April, May and June are the breeding seasons of river snails. Generally, each fetus can produce 20-30 young snails, many of which can reach 40-60. It can produce more than 0/50 snails per year. 2-3 weeks after delivery, the young snail weighs 0.025 grams and can start feeding. Generally, it can reproduce after feeding for one year. Usually, 65,438+000 ~ 65,438+050 snails can be put into the river snail culture pond per square meter; If natural waters are used, it is advisable to put 20~30 plants per square meter.
Question 3: Does the screw reproduce sexually or asexually? The life history of Schistosoma japonicum includes six stages: adult, egg, miracidium, cysticercus, cercaria and juvenile. People infected with Schistosoma japonicum or other mammals excrete eggs from feces. If feces pollute the water, eggs are brought into the water and larvae hatch in the water. Cysticercosis can swim freely in the water, and actively drill into the snails in the water, develop into female cysticercosis, and reproduce asexually to produce cysticercosis. After secondary reproduction, a large number of cercariae are produced, and the cercariae swim freely in water without snails. After people come into contact with water containing cercariae through various ways, such as production and labor, domestic water, swimming, etc., cercariae will quickly enter human skin, become larvae after entering the skin, grow and develop for a certain period of time, and finally settle in blood vessels near the liver and intestines and mature into adults. Female and male adults embrace, mate and lay eggs. Each female can lay two or three thousand eggs a day. This cycle is the life of Schistosoma japonicum, that is, the life history. In the life history of Schistosoma japonicum, there are two kinds of hosts, one is human and other mammals parasitized by adults, called definitive host, and many mammals can become the definitive host of Schistosoma japonicum; The other is snail parasitized by larvae, which is called intermediate host. Oncomelania hupensis the only intermediate host of Schistosoma japonicum. Oncomelania snail shell is conical, just like a small screw, hence the name Oncomelania snail. Oncomelania hupensis consists of shell and software. The soft part is the head, neck, feet and mantle in front, and the internal organs in the back. The shell has 6-8 spirals. The shell with longitudinal ribs on the surface is called ribbed shell snail, which is about 10 mm long and 4 mm wide and lives in areas with lakes and marshes or water networks. The light shell snail is slightly smaller than the ribbed snail, and its length and width are 6 mm and 3 mm respectively, which are more common in hilly areas. The shell of Oncomelania hupensis is oval, the periphery is complete, slightly turned outwards, and there are horny pieces. Oncomelania hupensis an amphibian, which can be divided into male and female. Oncomelania hupensis often active at the temperature of 15-20, and mainly feeds on algae. Oncomelania hupensis has a small range of activities, but it can drift to far places with the current, or it can attach to weeds or other floating objects and spread to far places. Straw sandals worn by people, gaps between cattle hooves, weeding or transplanting aquatic plants (such as reeds and water bamboo). ), and transporting fry will also spread snails. Oncomelania hupensis will "settle down" and breed in a suitable environment, forming a new breeding ground for Oncomelania hupensis. The life span of Oncomelania hupensis is generally 1 year, and some Oncomelania hupensis can live for 2-3 years or even more than 5 years. Oncomelania infected with Schistosoma japonicum miracidium is called infectious Oncomelania. The life span of infected snails is generally less than 1 year, and the longest can exceed 2 years.
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Question 4: How do the screws you usually eat at home reproduce? Are you talking about snails? If yes, I have the following answers:
(1) Selection of snail farms
Snail farms should choose places with sufficient water, good water quality, rich soil humus and convenient transportation. It is better to have running water.
Construction of aquaculture ponds. Generally, the width of snail pond is 1.5- 1.6m, and the length is 10- 15m, which can also be influenced by the terrain. Make a ridge around the pool, and the height of the ridge is about 50 cm. Water inlet and outlet are set at both ends of the pool water, and blocking nets are installed to prevent snails from escaping. At the same time, planting aquatic plants such as Zizania latifolia in the middle of the culture pond can not only improve the land yield, but also create a good ecological environment for the growth of Oncomelania hupensis.
(2), stocking quantity and feeding management
1, the stocking density of snails is generally per square meter 100- 120, and at the same time, about 5 species of silver carp and bighead carp are interplanted per square meter for main breeding. Snails are usually stocked in March.
2. Fertilization and feeding. In the culture pond, some manure is first applied to cultivate plankton and provide bait for snails. The amount of fertilizer applied depends on the bottom material of the snail pond. After the snails are put into the pond, they are fed with vegetables, rice bran, fish offal or vegetable cakes and bean cakes. Green horn and fish viscera should be chopped and mixed with feed such as rice bran. Vegetable cake, bean cake, etc. Should be soaked and softened to facilitate the feeding of snails. The feeding amount depends on the feeding situation of snails, generally calculated as 1%-3% of the total snail, and fed once every 2-3 days. Feeding time every morning, feeding position does not need to be fixed, and feed is put every other day. When the temperature is lower than 15℃ or higher than 30℃, there is no need to feed.
3. Water quality adjustment. First, the snail pond should be filled with fresh water frequently to adjust the water quality, especially in the breeding season. It is best to keep the pond water flowing, especially in high temperature season, and it is best to adopt running water culture. Micro-flowing water cultivation is the best in spring and autumn. The water depth of snail pond should always be about 30 cm. The second is to adjust the pH of water. When the pH value of the pool water is low, apply 0. 15-0. 18kg of quicklime per square meter and spray it every 10- 15 days to keep the pH value of the pool water at 7-8.
4. The overwintering management of snails. When the water temperature drops to 8-9℃, snails begin to hibernate. During hibernation, snails drill into the soil with the top of their shells, leaving only a round hole on the soil surface, and bubbles come out from time to time to breathe. Snails don't eat during the wintering period, but the water depth of the culture pond still needs to be kept at 10- 15 cm. Generally, change the water once every 3-4 days to maintain an appropriate oxygen content.
Question 5: How to cultivate snails with screws.
1. Pond selection: it is required to select an area of 3-20 mu, and the pond depth is 1- 1.5m, 1:3. The bottom of the pond is fat, but not too deep, and there is no requirement for the river water around the pond. As for the old pond, due to the lack of beach feet, snails like to live on less silt according to their habits. According to this feature, it is suggested that ponds and ridges can be laid to increase the adaptive area of snails. There is another way: enclose it with a net to further increase the snail culture area.
2. Pond cleaning: After the pond is selected, the pond should be cleaned, the ridge of the pond should be well made, and excess silt, especially the toe of the beach, should be removed. If possible, it is best to suck mud.
Three. Disinfection of ponds: pond cleaning is completely prohibited. Generally, the pond can be used for cleaning and disinfection, but it is best to use quicklime, and the dosage is water (30-50 cm)100-150kg/mu, and anhydrous 50-75kg/ mu. The quicklime cleaning tank has the following advantages: ① improving PH value; ② improve the quality of Ca; ③ Water quality can be adjusted; ④ Sterilization can be carried out.
4. Selection of snail species: ① Appearance requirements: the tip of the snail is short and swollen, and the shell is slightly prickly and reddish; ② Specification: 60- 100 capsules/kg; ③ Quality requirements: When the snail is frightened, it can quickly retract into the shell, free from diseases, injuries and insects.
5. Stocking time: after the medicinal properties disappear, stocking begins on the fifth day of/kloc-0, and ends around March 20th.
6. Stocking density: generally, 20-30 kg/mu is stockpiled in ponds, and it is best to interplant 2-3 kg/mu. The cultured snail shells are particularly tender and the meat is particularly fat.
Seven, summer stocking: fish (grass, crucian carp, bream) are mainly stocked in ponds, with 0.5-0.8 million fish per mu. In addition, cultivate 3-5 snails per mu, with the specification of 10/kg, and control the number of snails.
Eight, feeding and
Snails usually lay eggs many times, twice a year, once in spring and once in autumn. Our snail breeding mainly manages a batch of snails arranged before and after Tomb-Sweeping Day. Like others, it ovulates and matures in batches. Generally, young snails begin to eat after 2-3 weeks. At this time, you can feed and cultivate summer flowers at the same time. According to the biological feeding habits of snails, snails, like the main phytoplankton and humus (including debris) in drinking water, play a role through water filtration. As we all know, if there are too many snails, the water quality will become clear and even milky white. The water quality will get worse at this time. After this happens, especially in summer, the first thing to do is to change the water; Second, we should feed more soybean milk, bean cake pulp or whole pool fermentation. Feeding and fertilization should implement the principle of small amount and multiple times. If it is too much, it can be controlled by a small number of wafers. After summer flower cultivation, it is best to use vegetable cake or bean cake as feed. In water quality management, we must keep the water fresh and tender, because of water fertilization and feed.
Nine, implement the principle of grasping the big and letting go of the small. During the breeding period, in order to increase the output of snails, the principle of catching large snails and keeping small snails should be implemented. After 5-6 months, you can catch large snails (seed snails) first, and then catch standard snails gradually after 8 skeletons. In the future, snails can be caught in turn on 10- 15 days according to the growth of snails.
X. Daily management
⑴ Patrol the pond: Look at the fish's food intake every day to see if there is lack of oxygen in the water. If there is lack of oxygen, start the oxygen pump or change the water in time, because the oxygen content in the water is lower than 1.5mg/l, snails will start to die, and snails will also die when the water temperature exceeds 40℃.
⑵ Look at the color of water: Look at the water quality and fatty degree, and adjust the water quality in time.
(3) Disease prevention: It is mainly to prevent fish diseases and avoid using it as much as possible, because copper sulfate has a killing effect on snails. Generally, quicklime and bactericidal drugs or oral drugs are used to prevent and treat fish diseases. Quicklime should be used frequently in the whole breeding process, which can not only prevent diseases, but also increase calcium and adjust water quality. Generally, it is better to use it once every 0/5 days.
Question 6: I want to learn screw breeding. Can you? Generally, after putting a small screw in a fish pond, the screw will automatically reproduce. But the required fish can't eat screws. Like herring. And the water quality should be fatter. This kind of screw will grow faster!
Snails are omnivorous, fast growing, adaptable and easy to breed and raise, but they like shade and fear light, so they are suitable for rice field culture. Especially in areas rich in aquatic plants, it has great development potential and broad prospects. The technology of breeding meat snails in rice fields is introduced as follows.
1. Rice field selection. The snail paddy field should be dry and waterlogged, and the ridges should be compacted and raised to more than 0.5m Agricultural machinery should not be used for farming, and it is not suitable for ploughing, but weeds must be eradicated.
2. Water quality requirements. Screws are sensitive to dissolved oxygen in field water. When the oxygen content is lower than 3.5 mg/L, it will eat badly, and when the dissolved oxygen is 1.5 mg/L, it will start to die. Therefore, the water used in the field must have fresh water quality and high dissolved oxygen.
3. Paddy field facilities construction. Paddy fields should be arranged as strip pits with a width of 2~3m, and the water depth should be kept at 30~60cm. Some bamboo pieces and sticks should be put in the middle every 30cm for Oncomelania hupensis to absorb. You can also leave an empty passage when transplanting rice. Within 1 week after sowing, dig a high-yield ditch with a ditch width of 20~30cm and a ditch depth of 13 ~ 17cm, and set a dense-mesh fence or a polyethylene net with smaller mesh at the entrance and exit of the rice field. Around the ridge, prevent rats, snakes and other holes from leaking, so as to avoid snails fleeing.
4. Stocking and management of Ampullaria gigas.
(1) growth law. The growth rate of Ampullaria canaliculata is related to environmental conditions, food feeding and sex. In high temperature season, the water quality is good, the feed is sufficient and the growth is fast, and vice versa. The growth rate of middle snail is the fastest, and it slows down when the body weight is about100g. In addition, the growth rate of female snail is slightly faster than that of male snail. Under the condition of artificial culture, when the feed is sufficient, the newly hatched young snail can be raised for 1 month and its weight can reach about 25g. Feeding for 2 months can reach about 50g; It can reach100 ~150g in 3 months; It can reach about 200g in 6 months; Feeding 1 year can reach 400~500g g g.
② stocking. Snails in rice fields should be stocked in time, and the stocking density and specifications should be controlled. The stocking time should be from late June to early August 15 days after rice planting. Generally, 30,000-60,000 young snails with the size of 2-4 grams are stocked in each hectare of rice field. If the natural bait is rich, you can put more appropriately; On the contrary, it should be released less, so as not to affect the individual size and population yield of Ampullaria gigas.
③ Feeding management. The feed of Ampullaria canaliculata can be leaves and tender stems of various aquatic plants and terrestrial plants, and concentrated feed can be added to promote growth. Feeding time can be carried out at night, and duckweed and tender grass can be picked and fed at the same time. The daily feeding amount is about 10% of the total weight of snails, and the ratio of green feed to concentrated feed is 5∶ 1. Water quality management should be strengthened during feeding period, and water should be changed every 3~4 days 1 time. Fertilization of rice in snail field should be applied with sufficient base fertilizer 1 time before planting, supplemented by appropriate topdressing. In order to control pests and diseases in rice fields, low-toxicity and high-efficiency pesticides should be sprayed with water and not mixed in the soil.
5. Storage and management of screws.
① stocking. Breeding screws should be mastered flexibly according to the situation, generally 9 ~ 10.5 thousand per hectare. Seed snails can also be put in-generally 0. 1 ~ 05 kg per square meter.
2 feeding. Snails are omnivores. In addition to eating natural bait, you can also feed some vegetables, bean cakes, rice bran, earthworms and so on. And other animal offal and leftovers. The bait should be fresh, and the larvae can be fed 2 weeks after birth. When feeding, first soak solid bait, fish offal, animal offal, leftovers, etc. It should be chopped and then mixed with rice bran or bran for feeding. Feed/kloc-0 times a day, and the feeding time is generally appropriate at 8~9 am. The daily feeding amount is about l% ~ 3% of the total weight of the screw, and the food intake can be adjusted appropriately with the gradual increase of the weight. For some fertile rice fields, there is no need to feed on natural zooplankton and aquatic plants in the water.
When feeding, if it is found that meat overflows after the screw shrinks, it means that the screw lacks calcium. At this time, shrimp skin chaff and shell powder should be added to the bait. If the chip falls into the shell, it is caused by insufficient bait and hunger, so the amount of bait should be increased in time to avoid affecting the growth and reproduction of the screw.
③ Feeding management. The feeding and management of screws, the most important thing is to pay attention to water quality and water temperature. In summer and autumn, when you eat a lot of screws, it is also a high temperature season. Washing water is used to irrigate fields to reduce water temperature and increase dissolved oxygen. In addition, water sources and industrial wastewater with high iron and sulfur content must not be used, because this will directly lead to the death of snails. ...& gt& gt
Question 7: How do snails reproduce? Snails are hermaphroditic animals and need mating to reproduce. In addition, snails are oviparous animals and have a unique way of reproduction. The embryonic development and larval development of snails 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. At the same time of producing young snails, the male and female parents mate and fertilize, and at the same time, the young snails to be produced in the next year are propagated in the mother. A mother snail can produce about 100 ~ 150 young snails every year.
Question 8: How many batches of snails spawn in a year are oviparous animals, and their breeding methods are unique. The embryonic development of screws and the development of young snails are all completed in the mother. It takes about a blessing time from fertilized egg to snail reproduction in the mother. Snails lay eggs in batches and start breeding in March-April every year. At the same time of producing snail larvae, the male and female parents mate and fertilize, and at the same time, the snail larvae to be produced in the mother body are bred in the second year. A mother snail can produce about 100 ~ 150 young snails every year.
Question 9: There are many small screws in the fish tank at home, which breed quickly and eat aquatic plants. How to solve them? Put a few "ribbon pagoda snails" in and go to Taobao to search. There are many for sale, so do I, hehe, but I don't sell them ~
-Abang net tropical fish assistant.
Question 10: the screws have been in the fish tank at home for 3 years, and there are no small screws yet. How do the screws fit together? Will small screws grow at home? Snail is an oviparous animal, and its reproductive mode is very unique. The embryonic development and larval development of snails 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. At the same time of producing young snails, the male and female parents mate and fertilize, and at the same time, the young snails to be produced in the next year are propagated in the mother. A female snail produces about 100 to 150 young snails a year.
Snail reproduction: snails are hermaphroditic. The method to distinguish the sex of river snail is mainly based on the shape of its right antenna. The right antenna of the male snail bends to the right inside, and the bent part is the genitals of the male snail. In addition, the female snail is big and round, and the male snail is small and long. In nature, the proportion of female snails often accounts for 70% ~ 80%, and the number is much larger than that of male snails.
It is mating. Two snails are intertwined and then mate. After that, the mother snail climbs to the aquatic plants or branches above the water to lay eggs.