(1) Artificial Breeding. High-quality broodstock is essential for successful artificial reproduction. The parents should weigh over 10 kilograms and be fed with high-quality feed such as fresh small fish, livestock, or poultry. Alternatively, they can be given artificial compound feeds with a crude protein content of more than 40%. Regular water flushing is important, especially in the first month before spawning, to increase water stimulation. When the water temperature is suitable, select females with swollen, soft bellies and visible ovarian outlines, with red gonads. Gently press the belly of the female to check if the male releases sperm, which is used for oxytocin production. For artificial insemination, the male-to-female ratio should be 2:1, while for natural spawning it's typically 2:3. Common oxytocic drugs used in fish farming are effective, usually requiring one or two injections. At a water temperature of 22–23°C, the effect lasts about 12–14 hours. It's crucial to accurately determine the breeding time of the broodstock, catch them on time for egg collection, extract sperm, mix thoroughly, and ensure full fertilization. Hatching methods include natural hatching, hatching without adhesion, and using hatching baskets. Incubation tanks or small cages are commonly used, with water temperatures ranging from 17–28°C, ideally 23–25°C.
(2) Fry Cultivation. Fry ponds should be between 25–100 square meters with a water depth of 0.8–1 meter. Stocking density is around 1000–1500 fry per square meter. Once the yolk sac disappears and the fry start swimming normally, feeding can begin. Fry can be fed cooked egg yolks, microorganisms like rotifers or copepods. As they grow, they can be introduced to leeches, midge larvae, earthworms, or other small organisms. They can also be fed silkworm powder, pig blood, or commercial feeds. It’s important not to mix fry of different ages in the same pond. Since bigmouth bass are light-sensitive, it’s recommended to cover the fry pond. After 10–15 days of rearing, when the fish reach about 3 cm in length, they should be transferred to separate ponds.
(3) Fish Rearing. Young fish that are approximately 3 cm long are raised to 10–12 cm over a period of 30–40 days. This stage is critical for fingerling development. During this time, the fish must transition from live food to artificial feed, and it's also a period of intense competition among individuals. Water clarity should be moderate, as excessive clarity can lead to self-mutilation. Provide preferred feed and perform regular pond cleaning and grading. When the fish reach 5 cm, start introducing transfer feed—artificial feed mixed with attractants such as fish gills, shrimp shells, or animal livers. The transfer process takes 7–12 days. Feed 2–3 times daily, with a feeding rate of 15–20% of their body weight. Once 70% of the fish can consume artificial feed, switch completely to commercial feed. The feed should contain 42–48% crude protein, 8–10% crude fat, 25–30% carbohydrates, 6–8% fiber, along with vitamins and minerals. Proper management and disease prevention are essential during this phase.
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