Acipenser schrencki, commonly known as the Amur sturgeon, is originally native to the Heilongjiang River basin and is a freshwater fish with significant economic value and high potential for aquaculture. In 1998, it was introduced into southern aquaculture systems, specifically in Castanopsis kawakamii seedling farms, to take advantage of the favorable climate, clean water, and abundant natural feed sources that promote rapid growth. The goal was to develop a new, high-quality aquaculture species. After six months of feeding, the maximum weight recorded was 0.78 kg. Below are the key technical measures implemented during this process.
1. **Breeding Conditions**
The aquaculture ponds were cement pools constructed based on existing European oak breeding facilities, measuring 15 meters by 15 meters with a depth of 1 meter. Each pond was equipped with a waterwheel aerator to maintain oxygen levels. The water source came from surface sand-filtered fresh water, which was free from pollution, ensuring a healthy environment for the fish.
2. **Pond Preparation and Stocking**
Before stocking, the ponds were thoroughly cleaned and disinfected using a potassium permanganate solution at a concentration of 300 ppm. A total of 3,400 Amur sturgeon were stocked into two ponds, resulting in a density of approximately 9 fish per square meter. On the day of stocking, both the fish and the water were disinfected to prevent disease outbreaks.
3. **Feeding and Management**
- **Feeding Strategy**: Juveniles were initially fed silkworms until they reached 10–12 cm in length. Then, they were gradually transitioned to commercial bait to adapt their feeding habits. Feeding followed strict principles: qualitative (using sterilized silkworms and balanced bait formulations), quantitative (adjusting feed amounts based on fish weight), and timing (feeding live baits 6–8 times daily and artificial baits 3–4 times daily).
- **Water Quality Control**: Water was changed daily, with the volume adjusted based on fish size and season, typically between 50% and 100%. Dissolved oxygen levels were maintained above 5 mg/L. Ponds were cleaned every other day, and water temperature, pH, and other parameters were monitored regularly. Any abnormalities were addressed promptly.
- **Temperature Management**: Water temperature played a critical role in growth. The optimal range was 18°C–22°C. Shading structures were installed in summer to avoid overheating. Despite some challenges during feed transitions, the fish grew steadily, achieving an average weight of 0.507 kg after six months, with a daily gain of about 2.8 g.
4. **Disease Prevention**
Although A. schrencki has strong disease resistance, preventive measures were crucial, especially before fish reached 150 g. Hemorrhagic disease caused by *Aeromonas* was a major concern due to its rapid spread and high mortality. To mitigate this, disinfectants like chlorine dioxide and furazolidone were used every 5–10 days. Antibiotics and immune boosters such as vitamin C and E were added to the feed. As fish grew past 150 g, disease incidence significantly decreased.
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