Practical Experience and Methods for Seabass Farming

Seabass belongs to the order Perciformes and the subfamily Lateolabracinae, and is a euryhaline fish. It is distributed along the entire coast of China, with abundant resources. Seabass has the characteristics of fast growth, wide adaptability, strong disease resistance and delicious flesh. It is deeply welcomed by people. Its farming techniques are as follows:

1. Pond construction: Choose a place with abundant water sources and fresh, pollution-free water quality to build the pond. Each pond should be 5—8 mu, rectangular, with a north-south orientation being better. The pond bottom is required to be flat, with a sandy-mud substrate, firm pond banks, and a pond depth of 2 m. Inlet and drainage pipes should be buried at the pond bottom. At the same time, equip 1-2 aerators of 1.5 kW each, and the farm should have a backup generator set. Before stocking, the pond must be cleared of silt and disinfected. One week before releasing the fry, apply 50 kg of quicklime per mu or 5-10 kg of bleaching powder for dry pond spraying and disinfection. Before releasing the fry, fertilize to cultivate the basic feed organisms in the pond water, so that the pond water is preferably oily green or tea-brown.

2. Fry rearing: Seabass fry caught from sea areas (body length 1.5-2 cm) must be desalinated to a salinity of 4—7‰ and then put into a temporary holding pond (salinity 1‰). For the stocked variety, natural seabass fry from northern sea areas are the best. Due to different physical and chemical factors, the fry grow quickly and are large in size, which can shorten the farming cycle and increase economic benefits. The stocking density in the temporary holding pond should be controlled at 10,000-20,000 fry per mu, and the pond should frequently be flushed with water to increase oxygen. Starting on the 2nd day after entering the pond, feed live bait such as zooplankton and bloodworms. Gradually mix fish paste and floating pellet compound feed with live bait for feeding, and gradually acclimate them to feeding on minced fish paste and floating pellet feed. The daily feeding amount is 15% of the fish body weight, fed in 3 portions. During the temporary holding period, spray and disinfect once a week with 0.3 ppm strong chlorine or 15 ppm formalin. Three days before starting feeding, each 50 kg of fish should be given 0.5 g of furazolidone, 3 g of oxytetracycline and 1 g of vitamin C orally, mixed into the feed once a day, for 3 consecutive days. After more than 20 days of rearing, when the fish grow to 4-6 cm, they can be transferred to large ponds for separate stocking.

3. Feeding management: After sieving the seabass fry, stock them separately in ponds according to size. The stocking density is generally 2500-3500 fish per mu. The water depth should be more than 1.5 m, and the pond water should maintain suitable fertility, with a transparency of 30 cm and water color preferably oily green. Feed twice a day, mainly with minced fish paste and floating pellet feed. Vitamin B and C should be added to the feed, and the daily feeding amount is 6% of the fish body weight. Every month, also mix oxytetracycline, erythromycin and vitamin drugs into the bait and feed twice, each time for 3 consecutive days. At the same time, regularly spray and disinfect the whole pond with 0.4 ppm strong chlorine or 20 ppm formalin. For drug prevention and treatment, use drugs such as trichlorfon and mercurous nitrate with caution. Carry out pond patrol management every day, turn on the aerator at night or when the weather is muggy and the air pressure is low, and if the pond water is found to have deteriorated, drain and replace the water in time to keep the pond water fresh.

4. Disease prevention and treatment: Seabass has relatively strong disease resistance and is not prone to illness under natural conditions. However, because artificial high-density farming greatly changes its living environment and space, a slight carelessness can easily cause disease. Disease prevention must be strengthened, and farming ponds and feeding platforms must be regularly disinfected with drugs, and diseases should be treated early once found.