Commercial square head tilapia farming process

(Baonghean) - Square-head perch is an easy-to-raise fish, with a fast growth rate, delicious meat, bringing high economic efficiency, and developing strongly in the provinces of the Mekong Delta and the Southwest. In Nghe An, recently, the Nghe An Aquaculture Department has successfully tested this species through the implementation of the Project "Application of scientific and technological advances to build a model for commercial farming of square-head perch in Nghe An". The project has completed the process of commercial farming of square-head perch in Nghe An:



Squarehead perch at harvest time.

1. Prepare the pond

- Pond conditions: The pond has an area of ​​1,000 - 5,000m2, depth of 1.4 - 2m, bottom mud 15 - 20cm, soil pH = 6.5 - 8, the pond bank is solidly built, with active water supply and drainage.

- Pond renovation: Pump out the pond, clean around the pond bank, fill in water leakage holes, level the bottom, add lime to disinfect, kill weeds with a quantity of 7 - 12 kg/100m2, dry the pond bottom for 2 - 3 days.

- Creating water color: After taking water into the pond to create color: use 2 - 3 kg NPK/100m2 and sprinkle evenly into the pond to create an initial food source of algae and zooplankton for fish.

- Water intake: Clean water source, free of disease, free of pollution, water intake is filtered through a net to prevent pests and miscellaneous fish from entering the pond. Take 1.2 - 1.5m of water into the pond 2 - 3 days before releasing fish.

- Stretch nets around the pond bank to prevent fish from escaping.

2. Release the seed

Breed quality: Choose healthy individuals, without scratches, deformities, or defects, swimming quickly, with bright, uniform colors, no loss of mucus, and swimming in schools. Choose the right breed of square-head perch. Stocking size: 300 - 350 fish/kg. Density: 20 - 40 fish/m2.
Before releasing the fish, bathe the fish with 15 - 30‰ salt for 15 - 30 minutes.

3. Care and management

- Food: Use industrial pellet food with protein content of 25 - 30%. The conversion factor of industrial food is 1.6 - 1.8. Periodically add vitamin C and minerals with a content of 5g/1kg of food mixed into the food and feed the fish to increase resistance. The feeding rate for fish is 2 - 4% of body weight, depending on the weight and development stage of the fish. Feed the fish twice a day at 8 - 9am and 4 - 5pm.

- Water quality management: During the farming process, it is necessary to regularly monitor the water quality to be stable and clean. When the water color is light, it is necessary to fertilize with inorganic fertilizer with the amount of 1.5-3.0 kg of nitrogen and 0.8 - 1.5 kg of phosphorus/1,000 m2, depending on the water color to fertilize the appropriate dose, fertilize when the weather is cool. After fertilizing, it is necessary to observe the water color to avoid fertilizing too much, causing water pollution. Change the water to create a regular flow for the pond to avoid dirty water, fish are susceptible to disease. Always maintain the clarity of about 35cm. Regularly check the pH at about 7 - 8. If the pH decreases, use Zeolite to stabilize with the amount of 7 - 10 kg/1,000 m2. Periodically every 15 days, use lime to treat the pond water environment with the amount of 2 - 2.5 kg/100 m2 of pond.

4. Preventing and treating fish diseases

Squarehead perch are rarely sick. However, some common diseases in squarehead perch are bloating, black body, acute hemorrhage, water fungus, and ulcers. The causes of disease are due to improper feeding regimen, polluted pond environment or poor quality of food being used.

To prevent these diseases, it is necessary to adjust the diet and number of feedings per day appropriately, maintain the quality of the pond environment, periodically disinfect the pond environment and especially supplement vitamin C.

When fish are sick, it is necessary to correctly diagnose the disease (fungus, parasites, worms, flukes, bacteria...) to use the right and appropriate medicine, timely treatment combined with water environment treatment, limit the spread of pathogens, and avoid mass fish deaths.

5. Harvesting and preserving fish

a. Harvest

To harvest effectively and not affect the quality of commercial fish, the following methods are commonly applied:

- Selective harvesting: For commercial square-head perch, the larger the price, the higher the price, so the larger fish can be harvested first and sold, and the smaller fish can be kept for further farming. The selective harvesting method can use a net to collect fish.

- Overall harvest: For fish ponds that have reached a uniform large size, carry out a total harvest. Stop feeding the fish 1-2 days before harvesting. Use a net to collect some fish 1-2 days before pumping out the water. Pump out the pond water completely and continue harvesting.

b. Product preservation

After harvesting, square-head perch must be kept alive to increase the value of the product, so before harvesting, it is necessary to do a good job of specific preparation. It is necessary to contact and schedule a delivery date with the purchasing facility. Prepare tools and a place to store fish during the harvesting process to ensure clean water, with aeration to increase the survival rate after harvesting and overall sale. When harvesting, be gentle to avoid scratches that can easily kill the fish and quickly bring them to the fish storage point. For dead fish, quickly wash and refrigerate.

Ta Quang Sang (Nghe An Aquaculture Sub-Department)