Culture technique of big-mouth catfish

Big-mouth catfish is naturally distributed in the waters of major rivers south of the Yangtze River in China, with a common individual weight of about 2 to 5 kilograms. Artificial domestication and breeding began in the mid-1980s. The big-mouth catfish belongs to the catfish of the catlike order, with a wide and flat head, short and fat chest and abdomen, long and side flat tail, large eyes and mouth, fine and sharp teeth, 2 long whiskers, 2 short whiskers, scaleless body surface, rich mucus and short intestines, belonging to ferocious fish.

Environmental conditions of culture

Southern catfish is a warm water fish, the suitable water temperature for survival is 0: 38 ℃, the suitable water temperature for growth is 12: 30 ℃, and the most suitable water temperature for growth is 25-28 ℃. When the dissolved oxygen in the water is more than 3 mg / L, the southern catfish grows normally; when the dissolved oxygen in the water is less than 2 mg / L, the floating head begins to appear; when the dissolved oxygen in the water is less than 1 mg / L, it will lead to death. Southern catfish belongs to bottom fishes, which mostly lurk in groups at the bottom of the pond during the day and disperse at night. Southern catfish is gentle, not good at jumping, does not drill mud, and is easy to catch.

1. There are sufficient water sources and water quality in line with fishery standards, and it is convenient to enter and drain water.

2. The survival temperature is 0-38 ℃. The optimum growth water temperature is 24-28 ℃, the most suitable range of PH value is 7.0-8.4, and the requirement of dissolved oxygen in water is slightly higher than that of domestic fish. The growth above 3mg/L is normal. Above 5mg/L, the growth rate was the highest and the feed conversion rate was the highest.

Seedling Culture of Silurus meridionalis

The newly hatched fry are nourished entirely by their own yolk. In about 2 days, the yolk begins to disappear slowly, and when the larvae can swim horizontally, they can go down to the pond and open the mouth to eat. The open feed of fish fry can be cooked egg yolk or small Cladocera and copepod. Boil the egg, shell the egg yolk and wrap it with gauze. Squeeze the egg yolk in a plate filled with water to form a yolk granule water slurry and sprinkle it all over the pool. As the fish grows, it can be fed with water fleas, chironomid larvae, water earthworms, fly maggots and all kinds of small fish fry, or some silkworm pupa powder, pig blood, artificial seedling formula feed and so on. It is advisable to have a little leftover bait in the pond before the following feeding, so as to avoid cannibalism among fish fry due to insufficient feeding.

First improve the water quality, when there are a large number of rotifers in the pond water, put catfish seedlings, generally rearing 6000-10000 larvae of 3cm larvae per mu. Add fresh water once every 3 days, and then apply a small amount of chemical fertilizer. When the catfish seedlings have grown to 5-7cm, we should pay close attention to domestication and feed artificial compound bait. The protein content in the feed is more than 45%, and the fish species of different specifications are separated by trawling ponds to avoid eating each other.

3. The main purpose of feeding and management is to ensure adequate palatable bait, fresh water quality and rich dissolved oxygen, and strengthen the prevention of fish diseases.