Detailed Explanation of Key Technical Points for Stone Flounder Culture in Shrimp Ponds

In recent years, industrial marine fish farming has sprung up rapidly across the country. Marine fish culture in shrimp ponds has gradually gained recognition for its low input of equipment and materials and high output efficiency. The high-grade marine fish, stone flounder (Platichthys bicoloratus), is favored by a wide range of farmers for its tender flesh, good taste, rich nutrition, fast growth, few diseases, and strong market demand. Through experiments on stone flounder culture in shrimp ponds, the author achieved good economic benefits. The key technical points are as follows:
I. Conditions and Treatment Methods of Shrimp Ponds
1. The pond used for stone flounder culture should be close to the sea area. In summer, the maximum water temperature of the shrimp pond should not exceed 29°C, and the size should preferably be 15 mu to 30 mu. The water depth should exceed 2.0 m, with smooth water intake and drainage.
2. The pond bottom should be flat, mainly composed of fine sand with a diameter of 0.5 mm to 1.5 mm.
3. Treat the culture pond at the end of December by harrowing, sun-drying, and applying 60 kg to 80 kg of quicklime per mu to kill harmful bacteria, parasites, trash fish, and so on.

II. Stocking of Fry
1. First fertilize the pond. Begin taking in water in mid-March, preferably at night, mainly to cultivate the basic organisms on the pond bottom. By mid-April, fill the pond to a water level of 1.2 m. From the start of water intake, apply urea to fertilize the pond once every 5 to 7 days.
2. The fry are caught from nearshore shallow-water areas, overwintered indoors, and then stocked into the shrimp pond at the end of April when they reach a size of about 150 g. Before entering the pond, soak them in a 250×10-6 formalin solution for 3 to 5 minutes.
3. The stocking density is 800 to 1,000 fish per mu. After careful culture until September to October, each fish can exceed 500 g in body weight, and the culture survival rate can exceed 90%.
III. Culture Management
1. Feed Feeding
Mainly feed frozen fresh trash fish and shrimp and sand lance, with an appropriate amount of mysid shrimp. Feed twice daily, with the morning feeding accounting for 40% and the evening feeding 60%. The daily feeding amount is 8% to 9% of fish body weight. Feed at fixed times and fixed locations, and do not feed spoiled, deteriorated, or contaminated feed.
2. Domestication
Feed at a fixed location every day from 5:00 to 6:00 in the morning. First use a small amount of feed to attract feeding, and after most of the pond fish have gathered, increase the amount until they are full. After 1 month of such domestication, stone flounder will take food at fixed locations and fixed times.
3. Water Quality Management
Before early June, basically do not exchange water, only add water, with a daily addition of 5 cm to 10 cm, until the water level reaches 2.0 m. Begin exchanging water in mid-June, exchanging 10 cm to 15 cm daily. The water color of the pond should not fluctuate too much. During the high-temperature season from mid-July to mid-August, water temperature should be measured regularly every day. When the water temperature reaches or exceeds about 28°C, the water exchange volume should be increased to ensure suitable temperature conditions for stone flounder, promote its rapid growth, and help it reach market size as soon as possible.
4. Drug Prevention and Treatment
Strengthen daily disease prevention work. Every 15 to 20 days, feed feed mixed with antibacterial drugs for 3 to 5 days. At the same time, drive stakes at the feeding area and hang drug bags for external disease prevention.