The Mud Snail, commonly known as Huangluo, is a highly valued edible shellfish found in the East China Sea and South China Sea. It thrives in muddy subtidal environments and is renowned for its delicious meat and high nutritional value, making it economically significant. However, overfishing has led to a sharp decline in its natural population, prompting the development of artificial breeding techniques. Since 2004, the author has been conducting research on purse seine aquaculture in the Beigang shallow waters of Yuzhou Town, Zhanjiang, Guangdong Province. Over the years, a total of 8 mu of land was used for this method, with an average yield of 1,100 kilograms per mu and a profit of approximately 65,000 yuan per mu, proving its economic viability. Below are the key technical details that can be referenced by fellow aquaculturists.
First, the selection and preparation of the shoals play a crucial role. Ideal areas are those affected by typhoons, where the beach surface contains about 70% sand, with a long-wave drying time of 1 to 2 hours and seawater salinity ranging from 14‰ to 34‰. These areas should not have any fresh water inflow. Before introducing seedlings, the beach must be leveled using machinery, and predators like snails and crabs must be manually removed. The area is then treated with high concentrations of bleaching powder or lime to eliminate harmful organisms, and seedlings are introduced one week later.
Second, the fence setup is essential for effective culture. The fence consists of two layers, each 60 cm tall, with a spacing of 80 cm between them. The netting is made of polyethylene with a mesh size of 0.6 cm and a width of 100 cm. The net is secured with 8 cm diameter polyethylene ropes above and below, and embedded 40 cm into the seabed. Net poles are placed every 150 cm, using pine trees 150 cm long with a small end diameter of 6 cm, inserted 60 cm into the beach to form a 20m x 20m enclosure.
Third, the stocking process involves selecting healthy seedlings, which should be over 1 cm in length with bright, vibrant shells. Seedlings are transported using a dry method, packed in mesh bags at 0.5 kg per bag and placed in foam boxes. For long-distance transport, oxygen and ice are added to maintain quality. The survival rate after transport is typically over 99%. Stocking is done during low tide when the water level is around 30 cm, with a density of 500 seeds per square meter, evenly distributed within the fence.
Fourth, ongoing management includes feeding, monitoring, and disease prevention. The primary feed consists of small fish, crabs, and shrimp, with daily feeding amounts ranging from 5% to 10% of the snail’s body weight. Feeding is done when the water level inside the fence is between 20 cm and 40 cm. If the water level rises above the fence, feed may drift out, leading to waste and potential escape of the snails. Before feeding, leftover bait is removed to ensure efficiency. Regular checks are conducted to monitor snail activity, identify any abnormalities, and adjust feeding accordingly. The net structures are inspected frequently to prevent clogging and ensure smooth water flow. After storms, the beach is leveled, and net piles are reinforced to prevent loss of seedlings. During hot weather, measures are taken to manage temperature and avoid rainstorms. When snails reach 400 grains per kilogram, they are reared at a lower density of 300 grains per square meter.
Fifth, harvesting occurs after one year of growth, when the snails weigh about 160 grains per kilogram. Large catches can be obtained using crab traps, while smaller quantities can be collected during low tide after feeding, when the snails emerge to feed. Once harvested, the snails are washed with seawater, drained in a sieve, and placed in foam boxes for dry transport. In hot seasons, ice is added to keep them fresh. The transportation time is kept under 24 hours, and direct sunlight is avoided to maintain quality.
X Ray Lead Rubber Jacket
X Ray Front Lead Rubber Jacket,Xray Double Sides Lead Clothing,Half Sleeve Lead Clothing,Long Sleeve Lead Clothes
Longkou Kangxie Medical Instrument Co., Ltd , https://www.kangxiemedical.com