Rearing of Adult Snakehead Fish

The snakehead fish is a valuable freshwater fish of high economic value, known as the "treasure among fish." It is highly nutritious, containing large amounts of protein, more than that found in chicken and beef. From a nutritional standpoint, the snakehead fish is a comprehensive-nutrition, delicious-tasting premium health food.

Rearing of adult snakehead fish refers to the production process of raising fingerlings to food-fish size in small water bodies such as ponds, pools and cages. Artificial cultivation of snakehead fish includes two methods: extensive polyculture and intensive monoculture. Extensive polyculture means culturing them together with the four major Chinese carps in fish ponds. Intensive monoculture, on the other hand, uses conditions of abundant water sources and sufficient bait for high-density monoculture, and is divided into cage monoculture and pond monoculture. In recent years, pond high-density monoculture has been mainly adopted. It is briefly described below for reference only.

Preparation Before Farming

1. Farming facilities: earthen ponds, cement ponds, etc. The water depth should be 1 m to 2 m. Water supply and drainage equipment must be complete.

2. Water quality: pollution-free is required, and the water should preferably be neutral or weakly alkaline.

3. Area: the area of the fish pond should be somewhat small, preferably about 1 mu, and should not exceed 2 mu at most.

4. A 40 cm to 60 cm net barrier or other anti-escape facility must be installed around the pond.

5. Plant aquatic plants on the water surface around the pond, generally not exceeding about 20%, to provide shade from sunlight, help the fish escape the heat and catch food, and also purify the water quality and regulate water temperature.

Farming Techniques

1. Fingerling stocking: (1) Select fingerlings of the current year with a size of more than 10 cm; the fingerlings must be uniform in size, uninjured and disease-free. (2) For the source of fingerlings, it is best to choose locally produced fingerlings. (3) The stocking time is preferably from early September to early October, when the fish can feed and recover their condition, improving the overwintering survival rate. Stocking after the New Year is in March to April. (4) Disinfection: strict disinfection must be carried out before release into the pond. (5) Stocking density: at a water depth of 1.2 m to 1.5 m, stock 8000 to 9000 fingerlings of 50 g to 60 g per mu, or 5000 to 6000 fingerlings of 80 g to 100 g per mu.

2. Feeding management: feeding should adhere to the "four fixeds," namely fixed quality, fixed quantity, fixed time and fixed location. Before feeding, use tapping sounds as a "signal" to form a "sensory" response, gathering the snakehead fish around the feeding site, which makes it easy to form a feeding frenzy, increases food intake and reduces bait waste.

The types of bait are mainly fresh aquatic animals, primarily small marine and freshwater trash fish, shrimp, etc. When feeding is vigorous, the amount of bait is about 8% of the fish weight, and can reach more than 10% at most. During the off-season for feeding, it is 3% to 4%. When feeding, adopt a "slow, fast, slow" method; the feeding effect is good and feed waste is low. Once most of the fish are full and swim away, feeding can be stopped. When the weather, air pressure and water quality differ, the food intake of the fish varies greatly.

3. Daily management: mainly do well in the following aspects: (1) Pond inspection. Observe the fish's feeding, activity, changes in water quality, whether there are signs of floating head, whether there are diseased fish, etc., and deal with problems promptly when found. (2) Water changing. Snakehead fish take in high-protein bait every day, so the ammonia concentration in the pond water is relatively high, especially in summer when the water temperature is high, and the water body is very likely to deteriorate. For this reason, the water body needs to be replaced in time, generally replacing 1/3 every week and 4/5 every half month. Where conditions permit, it is best to maintain micro-flowing water for farming, and during the farming period the water temperature should preferably not exceed 30°C. (3) Preventing escape. As the snakehead fish gradually grows, its jumping ability increases, especially when changing water on rainy days or in the early morning, when jumping is very active. Therefore, the height of the pond ridge above the water surface should generally be greater than 50 cm, sturdy anti-escape nets should be installed at the water inlet and outlet, and anti-escape nets or anti-escape walls should be installed around the pond.

Diseases and Prevention

1. Saprolegniasis. Prevention and treatment method: be careful during net-pulling, transport and stocking operations to prevent injury to the fish body. When the fingerlings become diseased, they can be soaked in a 3% to 5% saltwater solution.

2. Myxosporidiosis. Prevention and treatment method: treat with 90% crystalline trichlorfon at a concentration of 0.2 ppm to 0.5 ppm.