Cultivation of Freshwater Whitefish in Ponds in Mountain Areas
During the years from 2004 to 2008, our station conducted a high-yield aquaculture demonstration project for freshwater ponds at the Sanxi Eco-Aquaculture Demonstration Center. This initiative lasted for five consecutive years and achieved an average yield of about 450 kg per acre without using any aeration equipment. The economic returns were impressive, and the following are the detailed methods we implemented:
**I. Pond Conditions**
The aquaculture center is located in Sanxi Town, approximately 18 kilometers from Chengguan. It is conveniently situated near the Huishuihe Irrigation Ditch, ensuring a steady and clean water supply. The drainage system is well separated, and there are no pollution sources nearby. The breeding pond is rectangular, oriented east-west, covering an area of 5 acres with a water depth of 1.4 meters. The bottom is flat, surrounded by a concrete slope with a ratio of 1:1.5.
**II. Pond Preparation**
Each year, after the winter season, the pond was dried and exposed to sunlight. By mid-April of the following year, we used quicklime to disinfect the pond. The application rate was 75 kg per mu. After stocking the fish, the water level was adjusted to around 1.1 meters after 10–15 days.
**III. Stocking of Fish Seedlings**
1. **Stocking Time**: Freshwater whitefish is a tropical species that cannot tolerate low temperatures. Therefore, stocking should only occur when the water temperature remains above 20–22°C. The optimal time is mid-May, not later than the end of May. It is best to stock on a sunny day during noon.
2. **Source and Selection**: The fish seedlings came from local fishing areas near Hefei. Those raised using waste heat from thermal power plants were particularly strong and well-proportioned.
3. **Quantity and Size**: We stocked 800 fish per acre, with each fish weighing between 14–16 kg. Before stocking, the fish were soaked in a 3–5% salt solution for 5–8 minutes and then placed in the pond for 1–2 hours. To improve water quality and utilize space, we also introduced squid species at a ratio of 6:1 (10–15 tails per acre).
**IV. Feeding Management**
1. **Fixed Feeding Points**: Feeding sites were fixed to help monitor the fish’s eating habits.
2. **Feeding Schedule**: Four feedings were done daily at 9:00, 11:30, 14:30, and 16:30. Pellet feed was used at 9:00 and 14:30, while a mix of soybeans and corn was given at 11:30 and 16:30.
3. **Feed Quality**: Only fresh, non-moldy feed was used. Main feeds included soybeans, corn, wheat, rice bran, vegetable cake, watermelon rind, animal offal, and slaughterhouse by-products.
4. **Feeding Quantity**: The amount of feed was adjusted based on fish growth, season, and weather. Fish weight was measured every 10–15 days. During the growing season, the feeding rate started at 3–4%, increased to 4–6%, and reached 7–8% in the later stages.
**V. Daily Management**
1. **Water Quality Control**: Water was changed by 15–20 cm every 15 days. During the hot summer months (July–August), water was added more frequently—10 cm every 5–10 days.
2. **Pond Patrol**: Daily inspections were carried out in the morning to observe fish behavior and water conditions. During high-temperature periods or thunderstorms, patrols were intensified to detect any abnormalities quickly.
3. **Disease Prevention**: Although freshwater whitefish has strong disease resistance, preventive measures were essential.
- **Bacterial Disease Prevention**: Quicklime was applied at 5–7.5 kg per mu to improve water quality and prevent bacterial infections.
- **Floating Heads**: Fresh water was added daily in summer to increase oxygen levels and prevent floating heads.
**VI. Key Technical Points for High Yield**
First, fish seedlings should be of suitable size and as uniform as possible. Second, since freshwater whitefish is an omnivorous bottom feeder, it should not be mixed with other bottom-dwelling fish, as this could reduce yield. Third, the best stocking time is mid-May when the water temperature stabilizes at 20–22°C. Early stocking may lead to unstable temperatures and lower survival rates, while late stocking can slow growth and affect market readiness. Finally, because these fish have a large appetite, feeding should follow the "four set" principle—small portions, multiple times, and not excessive.
Dental Portable X-Ray,Handheld Dental X-Ray,Portable Dental Xray Unit,Portable Dental X-Ray Unit
Rolence Enterprise Inc. , https://www.rolencedent.com