What are the specific water requirements for farming river snails?
For river snail farmers, if they want to obtain higher profits at the lowest cost, it is very necessary to understand river snail farming techniques. In fact, river snail farming has relatively high water requirements; it requires maintaining a slight flow of water, so as to ensure the oxygen needs of the river snails in the water.
Water requirements for farming river snails
Regarding the water requirements for river snail farming, the pond used for farming river snails needs shallow water, and shallow water easily causes the water temperature to rise (especially in summer), leading to a lack of oxygen in the pond water. Therefore, the farming pond is best able to maintain a slight flow of water. This requires building water inlet and drainage outlets, and installing wire mesh intercepting facilities at each water outlet to prevent the river snails from escaping with the water flow.
If spring water or well water is used to farm river snails, the water requirements for river snail farming require some oxygenation measures:
1. First pump the spring water or well water up to a storage tower, then let it rush down from a height so that it absorbs oxygen from the air before being poured into the farming pond.
2. Dig water inlet ditches so that the incoming water passes through a longer course and is fully exposed to sunlight and wind, thereby increasing the contact between water and air and thus increasing the dissolved oxygen in the water.
River snail farming techniques
1. Site selection for farming
River snails have strong stress resistance, few diseases, and a high reproduction rate, and they have low requirements for farming sites. Many ditches, flooded fields and marshlands, and ponds in rural areas can be used for stocking. If it is an open pond, red azolla, duckweed, water hyacinth and other shading plants can be grown on the water surface, and bamboo poles, wooden sticks and the like can be inserted in the pond for river snails to rest on. This can both harvest aquatic green manure as feed and raise river snails to increase income.
2. Collection of seed snails
River snails mostly reproduce naturally. For artificial farming, they can be picked up from paddy fields, wild rice stem fields, and muddy ditches, or bought from the market, and then live snails with light brown color, thin shells, round bodies and blunt tails are selected as seed snails. Generally, river snails with a body weight of 15-25 grams have reached sexual maturity, and they can reproduce at temperatures above 15°C. Female snails are large and round, while male snails are small and pointed.
3. Stocking and reproduction
The most suitable growth temperature for river snails is 20-25°C. If it is below 15°C or above 30°C, river snails stop feeding, and below 10°C they burrow into the soil to hibernate. South of the Yangtze River, stocking can be done from March to November. If stocking in a natural area, putting in 11 seed snails per square meter is sufficient (3 males and 8 females). If a pond is dug for single-species farming, 100-500 can be stocked per square meter, the water depth is preferably 0.8-1 m, and a layer of more than 10 cm of silt is retained at the bottom of the pond to facilitate the river snails' crawling, feeding, and resting. When stocking, male and female snails are put in together and they can reproduce naturally.
4. Feeding and raising
River snails are omnivorous animals. Rice bran, vegetable scraps, melon leaves, animal carcasses and commercial feed can all be fed to them. Generally, aquatic plants, soil humus, vegetable and melon peels and the like are the staple food. In fertile paddy fields, fish-snail mixed farming, or low-lying areas where red azolla, green azolla, water hyacinth and the like are grown on the water surface, feed can be given less or not at all.
5. Reproduction management
River snails are viviparous animals. In the south, April to May and September to November each year are the reproduction periods. Female snails generally give birth in batches, and each river snail can produce 20-30 small river snails each time. After giving birth, the mother snail needs 14-16 months before it can reproduce again. Newly born small snails weigh 0.5-1.5 grams, and after 6 months of raising they can reach more than 3-5 grams, and after 9 months they can reach about 9 grams.
6. Catching and harvest
When catching river snails, adult snails should be selectively taken, and more mother snails should be left. Harvesting can be done in batches. In midsummer and early autumn, when the water temperature is relatively high, river snails mostly hide in the soil and among grass clumps at noon, so they must be picked up in the morning and evening, or the water can be drained for picking. For every 100 mother snails stocked, the annual yield can reach 100 kg.
Construction of river snail farming ponds
1. Site selection for farming: River snails have strong adaptability and few diseases. As long as they avoid poisoning by large amounts of pesticides and chemical fertilizers, many ordinary water bodies in rural areas, such as flat rivers and canals, stream banks, pits, paddy fields, and ponds, can be used for stocking.
2. Pond construction: River snail farming ponds are generally 1.5 m wide, 10-15 m long, and 30-50 cm deep. Between two ponds, build a 20 cm high embankment for walking. Spread a 10 cm thick layer of fertile mud at the bottom of the pond. Aquatic plants such as wild rice stem, asparagus, water lettuce, and duckweed can be sparsely planted in the pond to shade the river snails from the sun and heat, provide climbing and resting places, and supply bait, improving the utilization rate of the snail pond. Build a 60-80 cm high wall or mesh fence around the snail pond.
3. Pond disinfection: In river snail farming, the use of sodium pentachlorophenate for pond clearing is completely prohibited. Generally, quicklime or bleaching powder can be used for pond clearing and disinfection, but quicklime is the best. The dosage is 100-150 kg per mu with water (water depth 30-50 cm), and 50-75 kg per mu without water. Clearing the pond with quicklime has the benefits of increasing pH, increasing calcium content, regulating water quality, and killing viruses and bacteria.
Farming methods for river snails
1. Selection of seed snails: River snails mostly reproduce naturally. For artificial farming, they can be picked up from paddy fields, wild rice stem fields, and muddy ditches, or bought from the market, and then live snails with light brown color, thin shells, round bodies and blunt tails are selected as seed snails. Generally, river snails with a body weight of 15-25 grams have reached sexual maturity, and they can reproduce at temperatures above 15°C. Female snails are large and round, while male snails are small and pointed.
2. Stocking time: Snail seed stocking can be done all at once in sufficient quantity, or put in in multiple batches. However, considering improving the survival rate, it is generally necessary to avoid the hot and scorching period. Of course, stocking at the end of the previous year helps shorten the farming time and increase the yield for that year.
3. Stocking method: If stocking in a natural area, putting in 11 seed snails per square meter is sufficient (3 males and 8 females). If a pond is dug for single-species farming, 100-500 can be stocked per square meter, the water depth is preferably 0.8-1 m, and a layer of more than 10 cm of silt is retained at the bottom of the pond to facilitate the river snails' crawling, feeding, and resting. When stocking, male and female snails are put in together, and they can reproduce naturally.
4. Mixed farming: To regulate water quality, 20-50 silver carp of 20-50 grams each and 5-10 bighead carp of 20-50 grams each may be raised per mu. Snail ponds should not be stocked with carnivorous or partially carnivorous fish such as black carp, common carp, crucian carp, and yellow catfish.
Everyone should not underestimate this small river snail. Although it is quite delicious when eaten, behind every delicious portion is the hard work of the farmers, as the saying goes, “every single grain is the fruit of hard work.” However, if some reasonable techniques and farming methods are mastered, farmers can avoid many detours, which saves both effort and worry.