When is the breeding season for farmed river snails?
As people's living standards continue to rise, the delicious taste of river snails is now known to more and more people, so wild river snails are far from meeting people's needs, and therefore more and more people are joining the river snail farming industry. In the process of farming river snails, the breeding of river snails is relatively important.
The breeding season for farmed river snails
The annual breeding peak of river snails is divided into three stages. They generally begin breeding in April, with June's first ten days, mid-August and late September being the peak breeding seasons, continuing until the end of October.
The age at first reproduction for river snails is 1 year, and breeding begins above 15°C. Each snail produces about 20 to 30 young snails per brood; breeder snails aged 4 years or older can produce 40 to 50, and those aged 5 years or older can produce 50 to 60. The number of offspring is related to the age of the breeder snail and environmental conditions. From fertilized egg to the birth of the young snail, it takes about 1 year of development inside the mother's body. Every year from March to April, river snails begin to breed, becoming lively and mating frequently. When you see female and male river snails embracing each other and turning up and down sideways, that is the mating behavior of river snails. The sperm and egg fertilize at the top of the oviduct; the fertilized egg goes through the blastula and gastrula stages, then through the trochophore and veliger larval development stages, and finally develops into a young snail. The embryonic development of the river snail, right up to the development of the young snail, all takes place inside the snail's body, so the river snail is ovoviviparous.
During the breeding season of river snails, July to August is the peak reproductive season. The young snails to be produced the following year are carried in the abdomen, and are born in March to April of the following year; after that they mate again and carry young snails in their bodies once more. In a river snail population, females are often more numerous than males. Out of 100 river snails, females account for about 75% to 80%, while males make up only 20% to 25%. During the reproductive season, because males mate frequently with females, the lifespan of males is only half that of females. The lifespan of males is generally only 2 to 3 years, while that of females can reach 4 to 5 years, and some females can live to 6 years or more. The young snails produced during the breeding season of river snails weigh 0.025 grams each 15-20 days after birth. Young snails born early in the season can grow to a body weight of 6 to 8 grams within the same year, and under artificial farming can reach 12-15 grams, with growth especially rapid during the first 3 months.
Prospects for river snail farming
River snail meat is a nutritious natural health food, and abroad it is also known as a beauty food. It contains 10.3% protein and 1.2% fat, as well as vitamins, calcium, iron and other elements essential to the human body. River snail meat is nutritionally superior to chicken, duck, goose and pork, and is no less than crucian carp or sea cucumber. River snail meat can nourish kidney yin, improve eyesight and clear the mind, enhance muscle elasticity, and refine the skin.
River snails can be used as an everyday meat dish, and can also be processed into a series of foods, prepared into various medicinal dishes, and used to prevent and treat disease. At present, naturally growing river snails are far from meeting market demand, and river snail farming offers fast growth and high yield, so farming river snails has broad "money" prospects.
High-yield farming techniques for river snails
1. Choosing a site
River snails have strong vitality and disease resistance, and can be stocked in ditches, paddy fields and shallow ponds with a source of living water. Pond-based farming is generally adopted. Snail ponds are generally 2-3 m wide and 10-15 m long, with embankments built around the pond 0.7 m high, and netting installed around the perimeter to prevent the river snails from escaping. Spread 20 cm of fertile mud on the pond bottom, fill with fresh water, and grow water hyacinth, small gourd, red and green duckweed, etc. on the water surface to provide food for the river snails. Insert small bamboo poles or wooden sticks in the pond for the snails to perch on and lay eggs.
2. Stocking seed snails
Select breeder snails or young snails and put them into the pond. After the pond is built, stocking is generally carried out from April to November. Every year from June to September is the season when river snails lay eggs in large numbers; you can pick them up in rice fields and ditches, or buy them at the market. The characteristics of female snails are: light brown color, relatively thin shell, relatively round body, blunt tail. Select female snails of 15-20 grams and put them into the pond; generally, stocking 10 female snails per sq m is sufficient. If young snails are chosen as seed stock, stock them at a female-to-male ratio of 2:1. Female snails are larger, with a rounder body and a flat, concave operculum; male snails are slightly smaller, with a longer body and a raised operculum. Young snails can be harvested for market after about one year of farming.
3. Feeding and management
River snails have abundant food sources; microorganisms in the water, organic matter, and the tender stems and leaves of aquatic plants are all their main food. During the peak growth season for young snails, from April to November each year, supplement with rice bran, wheat bran, tofu residue, cooked sweet potato, small insects, small fish and shrimp, and animal offal. Compound feed can also be given. Feed once a day at 8-9 o'clock; larger feed items should be chopped up before feeding. The daily feeding amount is about 1.5% of the snail's body weight. Replace the water regularly to keep the water quality fresh, changing the water about once every 10 days. When the water temperature is above 30°C, frequently add fresh water and deepen the water level; at ordinary times keep the water depth at 30 cm. In winter, lower the water level during the day to increase light exposure, and deepen the water level at night. This keeps the pond warm; combined with applying some pig manure and barnyard manure, it raises the temperature and enriches the water quality. River snails are relatively sensitive to pesticides and industrial sewage. Take care to avoid these, and also watch out for damage by ducks.
4. Harvesting for market
After one year of farming, those reaching a body weight of 15 grams or more can be harvested for market. Harvesting methods can be either draining the pond or harvesting in shallow water. At the same time, take care to leave some female snails to prepare for breeding young snails the following year.
5. Overwintering management
When the water temperature drops to 8-9°C, river snails begin to hibernate. During hibernation, they burrow into holes, leaving a small opening on the soil surface and occasionally bubbling. At this time they neither eat nor move. Keep the water depth at 10-15 cm, and change the water once every 4-5 days to increase the oxygen content so the river snails can overwinter safely.
Nutritional value of river snails
Rich in protein, it helps maintain potassium-sodium balance, eliminates edema, improves immunity, lowers blood pressure, buffers anemia, and benefits growth and development. Calcium is a basic raw material for bone development and directly affects height; it regulates enzyme activity, participates in nerve and muscle activity and the release of neurotransmitters, regulates hormone secretion, regulates heart rhythm, reduces cardiovascular permeability, controls inflammation and edema, and maintains acid-base balance.
Rich in copper, copper is an indispensable trace nutrient for human health and has important effects on blood, the central nervous system and the immune system, hair, skin and bone tissue, and the development and function of internal organs such as the brain, liver and heart.
1. Clearing heat: river snails can clear the heart and purge fire, clear heat and relieve irritability, and can eliminate heat toxins in the blood. They can treat heat-related difficult urination, jaundice, athlete's foot, hemorrhoids and bloody stool.
2. Diuresis: contains diuretic components, can eliminate water and sodium retention in the body, and promote diuresis and reduce swelling. Can treat edema, red swollen painful eyes, and boils and swellings.
3. Quenching thirst: moistens the throat and removes dryness, making people feel refreshed and comfortable. Can treat wasting-thirst.
4. Sobering up: river snails can neutralize the toxicity of ethanol and promote its rapid excretion after drinking.
The nutritional value of river snails is very rich, and river snails also have many benefits for the human body, so the demand for river snails on the market is relatively large. When farming river snails, farmers should have a clear understanding of the development prospects, current situation and farming techniques of river snails, so as to lay a certain foundation for success.