Stingray high yielding method

Before stocking, drain the pond for seven days and disinfect it using 100 kg of fresh lime per 667 square meters (1 mu). On the third day, refill the pond with clean water and use 901 mesh fish nets to eliminate predators like leeches and cockroaches, which improves the survival rate of stingrays.

2. Fish Fry Stocking: Yellow sturgeon fry are typically bred in the Poyang Lake region and can be stocked when they reach 1.5 cm in early June. They are usually raised in concrete pools or small earthen ponds for about 10 days until they grow to 3 cm. After that, they are moved into larger ponds. During this holding period, they are mainly fed red worms and fish larvae, later transitioning to powdered compound feed. The stocking density depends on pond conditions and feed availability. Usually, 5,000–8,000 fry per 667 square meters is common. After 120–150 days of feeding, the fish can reach 100–150 grams, yielding 500–800 kg per 667 square meters.

Stingrays are generally calm and not aggressive, so they shouldn’t be mixed with other fish species. It’s recommended to introduce larger fish like silver carp or bighead carp (over 100 g) at a density of about 200 per 667 square meters, which can produce up to 150 kg.

Before stocking, fry should be disinfected using a 3.5% salt solution or 60 mg/L formaldehyde bath for 5 minutes to kill surface pathogens and parasites. Due to high temperatures, it's best to use color cloth cages to prevent stress.

3. Feeding Practices: Stingrays are omnivorous, consuming both plant and animal matter. To achieve high yields in intensive farming, it's important to provide large amounts of high-quality feed and implement scientific feeding practices. Set up 2–4 feeding stations and train the fish to eat at fixed times and locations. Before reaching 20 grams, feed them crushed fish and powdered compound feed mixed with water to form lumps. When the fish weigh 20–50 grams, switch to 1.5 mm-sized feed with 35–40% crude protein. Once they exceed 50 grams, use 2.5 mm-sized feed with around 30% crude protein.

During the growing phase, follow the "four determinants" feeding principle: fixed location, fixed time, fixed quantity, and fixed quality. Feed 1/3 of the daily amount between 9–10 am and 2/3 between 4–5 pm, each session lasting 30 minutes. Use a slow-fast-slow feeding rhythm to prevent nutrient loss. Adjust the daily feeding rate (3–8%) based on water temperature and fish growth. Ensure the feed is fresh, nutritious, and of high quality. Under normal conditions, the feed conversion ratio is around 2.5. Wild fish in the lake area can also be used as feed to reduce costs.

4. Water Quality Management: Stingrays prefer clean, well-oxygenated water with at least 5 mg/L dissolved oxygen throughout most of the day, and no less than 3 mg/L. High-density farming and heavy feeding can lead to poor water quality, causing oxygen depletion and fish mortality. Regularly flush and replace pond water to keep it fresh and clear. Use aerators effectively to enhance oxygenation and prevent eutrophication, which can cause low dissolved oxygen levels.

5. Disease Prevention: While stingrays rarely suffer from diseases in natural waters, intensive farming increases the risk of bacterial and parasitic infections. Clean feeding tables regularly, remove leftover food, and disinfect them. Periodically treat the water with 0.3 mg/L chlorinated lime or 20 mg/L formaldehyde, combined with 0.7 mg/L copper sulfate and ferrous sulfate. Administer furazolidone orally at 0.5 g/kg of feed for 7 days. If necessary, treat severely affected fish with a 50–60 mg/L formaldehyde bath for 5 minutes. Applying 15 kg of lime per 667 square meters every two weeks helps maintain water quality and prevents disease spread.

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