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Wan Songliang, from the Hubei Fisheries Research Institute in Wuhan (430071), has made significant contributions to the development of aquaculture for Silurus meridionalis, commonly known as the southern bigmouth catfish. This large, economically valuable fish is native to the main stem of the Yangtze River and is prized for its fast growth, adaptability to various temperatures, excellent meat quality, and high market demand. The successful domestication and large-scale breeding of this species have played a vital role in boosting China's aquaculture industry and meeting consumer needs.
Since 1987, a comprehensive nine-year research project was conducted, focusing on the biological characteristics of bigmouth larvae, gonadal development, embryonic and post-embryonic development, oxygen consumption rates, anatomical structures, nutritional analysis, blood indices, and isozyme studies. The research also involved systematic investigations into broodstock collection, early maturation, artificial propagation, seedling cultivation, and adult fish farming. As a result, advanced techniques for artificial breeding and farming were developed and widely promoted across more than a dozen provinces in China, yielding substantial social and economic benefits.
The key features of the technology include:
1. A thorough understanding of the biological traits and growth patterns of bigmouth catfish under artificial conditions.
2. Selection of high-performing larvae from the middle reaches of the Yangtze River through comparative breeding experiments.
3. Successful artificial propagation with 100% broodstock yield, 98% fertilization rate, and 95% hatching rate, producing over five million fry annually.
4. Development of advanced breeding methods such as small water bodies, high-density stocking, full artificial feeding, and intensive seedling rearing, achieving an 85% survival rate for 3–4 cm fingerlings and over two million 3–10 cm seedlings per year.
5. Maturity in artificial farming techniques, with pond production reaching 7,500–11,250 kg/ha per season, and single-crop yields of 5,250 kg/ha. Net profits range from 51,000 to 22,000 yuan per hectare, while polyculture increases production by 20–25 kg and income by 400–500 yuan. Cage culture produces over 500 kg per 28 m² box, with nearly 10,000 yuan in net profit.
This technology has been implemented in 12 provinces, including Hubei, Hunan, Guangdong, and others, distributing nearly 8 million fry and generating direct economic benefits of 1.5 million yuan, along with over 50 million yuan in social value.
Key technical points include:
1. Detailed study of morphology, biology, and distinguishing features like fin shape and gonad development.
2. Cultivation of high-quality broodstock with temperature and artificial ripening techniques to advance spawning by two months.
3. Construction of specialized facilities for incubation and nursery ponds.
4. Hormone injection for broodstock at late gonadal stages, followed by artificial insemination and controlled water temperature for optimal hatching.
5. Intensive rearing using small water bodies, high density, and live feed, achieving high survival rates for fingerlings.
6. Efficient pond and cage farming methods with specific stocking densities and feeding strategies to maximize yield and profitability.
These advancements have not only enhanced the commercial viability of bigmouth catfish but also contributed significantly to sustainable aquaculture practices in China.