1． Fry cultivation

(1) Water splashing: It is better to cultivate largemouth catfish fry intensively in small water bodies in the South. In April every year, when the natural water temperature stabilizes above 18°C, pure southern largemouth catfish flowers can be purchased from the nursery. The stocking density is 1000-1500/ (the specific number is determined by the breeding conditions), and the water temperature difference when stocking the seedlings should not exceed 3°C.

(2) Feeding:

The fry will mainly feed on water fleas before their body length is 8cm. Daphnia can be fished from natural water bodies. As the fry grow, the amount of water fleas required gradually increases. However, in actual production, the amount harvested is often insufficient. To this end, water fleas should be cultivated artificially. The specific method is: half a month before purchasing water flowers, select an earthen pond with a depth of 10 to 30 degrees and a water depth of 0.5 to 1 meter, inject fresh water, and keep the water temperature at 18 to 25 degrees Celsius. Apply 2.0 kilograms of manure per square meter of water surface, and then apply fertilizer once every two days, with 0.8 to 1 kilogram of fertilizer per square meter of water surface each time. When the pool water reaches a certain fertilizer level, introduce 20 to 30 grams of flea species per cubic meter of water, and 5 In ~10 days, water fleas will multiply in large numbers and cover the entire pond. At this time, water fleas can be harvested and fed to the fry.

If the water temperature is relatively stable and the bait is sufficient, the fry can reach more than 3 cm after about 10 days of cultivation.

2. Cultivation of fish species

When southern largemouth catfish fry grow to more than 8cm, their food intake increases. Simply relying on the amount of water fleas cannot meet their needs, so they can be cultivated with fish paste and water earthworms.

(1) Fish slurry cultivation method: When the fry grow to more than 3cm, the fish meat and earthworms can be beaten into a slurry, and 0.2% to 0.3% of the fish attractant (glycine trimethylester) can be mixed ), put it into the water body, let it slowly eat surimi, and then gradually increase the amount of surimi until it eats surimi completely.

(2) Water earthworm cultivation method: When the fry grow to 3cm, gradually reduce the amount of water fleas fed and increase the amount of water earthworms until they are completely fed with water earthworms.

Water earthworms can be fished from shallow ditches with rich soil humus and micro-flowing water in the wild. It can also be obtained by artificial cultivation methods. The cultivation method is: regardless of the size of the pond, lay a layer of silt on the bottom of the pond with a thickness of 8 to 10 cm and a water depth of 30 to 40 cm, then introduce a few earthworm seeds, use fermented wheat bran and rice bran as feed, and feed 1 pellet every 3 to 4 days. times, 250 g/m2 each time. When a certain amount is reached, it can be harvested and fed. Using this method, 8 to 26 grams of water earthworms can be produced per square meter of water surface per day.

3. Daily management

(1) Dissolved oxygen: The dissolved oxygen requirement in southern largemouth catfish breeding ponds is above 3 mg/L, and floating heads will appear when it is as low as 2 mg/L. During production, water is generally injected every 3 to 5 days. Pay attention to the water temperature difference not exceeding 3°C to keep the water quality tender and green. Micro-flow water culture can be used if conditions permit.

(2) Water temperature: The suitable survival temperature for southern largemouth catfish is below 38°C, and the optimal water temperature for growth is 18°C ??to 32°C. During the fry and fingerling cultivation stage, if the water temperature in nature is low, changes frequently, and the water temperature is unstable, timely attention should be paid to water body insulation. In production practice, film covering can be used to increase the water temperature.

(3) Feed: Feeding method: Feeding of feed should adhere to "timing, fixed point, fixed quality and quantitative". Feed twice a day, 9:00 to 10:00 in the morning, the feeding amount accounts for 40% of the daily feeding amount, and 18:00 to 20:00 in the afternoon, accounting for 60% of the daily feeding amount, the total daily feeding amount It is 6% to 8% of the fish body weight.

(4) Graded cultivation: Southern largemouth catfish grows unevenly during the fry cultivation stage. When it reaches more than 3 cm of water, individual growth rates vary greatly, and they have the habit of cannibalism. The big mouth catfish often eats the small ones, so it is necessary to Breed in separate pools in timely manner and strictly control density.