Culture techniques of Wuchang fish

Wuchang fish, commonly known as blunt snout bream, shrinking item, mainly lives in rivers and lakes. It usually lives in the middle and lower layers of the water. The main food is bitter grass, verticillium verticillata, molluscs and detritus of lake bottom plants, filamentous green algae, freshwater sponges and so on. The spawning period is from May to June, when pearls appear on both sexes. It is distributed in Heilongjiang, Yangtze River, Pearl River, Qiantang River, Minjiang River and other lakes such as Dongting Lake, Poyang Lake and Liangzi Lake.

The living habits of Wuchang fish

1. Summary: distributed in medium-sized lakes attached to the middle and lower reaches of the Yangtze River. More suitable for static water life. It usually lives in the middle and lower layers of the open water area where the sediment is silt and there are submerged plants. Juvenile fish mainly feed on Cladocera and crustaceans, while adults feed on aquatic plants, mainly bitter grass and verticillata, and a small amount of zooplankton.

2. Feeding habits: Wuchang fish is herbivorous, and its feeding ability and intensity are lower than that of grass carp. Fish species and adult fish mainly feed on aquatic vascular plants such as bitter grass, verticillium verticillata and Rabdosia angustifolia. They also like to eat terrestrial Gramineae and vegetable leaves, and can also eat some detritus of lake bottom plants and a small amount of zooplankton, so they have a wide range of feeding habits. Food intake usually begins in April and continues until November, with the highest food intake from June to October.

3. Growth: Wuchang fish is a medium-sized fish with a fast growth rate, with the fastest growth at the age of 1 to 2 years old. Under the condition of abundant aquatic plants, the average body weight of fish in the same year can reach 100,200g; the weight of second-year-old fish can reach 300kg; after that, the growth rate slows down gradually, and the largest individual can reach 3000kg.

Culture conditions of Wuchang fish

1. Pond conditions: the pond area is 3000 square meters to 10000 square meters, the water depth is more than 2 meters, it is rectangular, it is better not to leak. The bottom of the pond is flat and the silt is about 20 cm thick. It should be equipped with machinery such as drainage and irrigation, feed processing, transportation and oxygen enrichment. The power of the pond fishing machine should be more than 0.5 kilowatts per mu. The ponds are required to be relatively centralized and easy to manage.

2. Water quality conditions: sufficient water source, fresh water quality, no pollution. The transparency of the pond water is 30 cm ~ 35 cm, the dissolved oxygen content is about 5 mg / L, not less than 2 mg / L, and the pH value is between 7 and 8. Regular water injection is required during the culture period, and water injection is 20 cm ~ 30 cm every half month from July to September.

Fish fry propagation of Wuchang fish

Wuchang fish can reach sexual maturity at 2 and 3 years old, and the breeding season is a little later than that of common carp and crucian carp, and earlier than that of domestic fish. In the middle and lower reaches of the Yangtze River, the spawning period is mostly from the end of April to the beginning of June, that is, the water temperature is between 20 and 29 ℃. In lakes, eggs are laid in places where aquatic plants flourish, and fertilized eggs are sticky and develop on aquatic plants or other objects. The parent fish of Wuchang fish cultivated in the pond can cause non-concentrated natural spawning if there is micro-running water or other stimulation in the breeding season. Therefore, after the beginning of spring every year, the male and female parent fish should be cultivated separately. At that time, artificial estrus will be promoted, and the fish fry will be produced in batches.

Artificial reproduction of fish fry can be done by natural spawning or artificial spawning. Parent fish for breeding are best cultivated in a pond for a year, or they can be selected directly from natural water bodies. It is relatively easy to identify the male and female of Wuchang fish. From the fish species stage, the first fin of the female pectoral fin is thin and straight, while the thickness of the male fish is "wavy". After sexual maturity, there are dense "pearls" on the back of the front fin of the male pectoral fin, the dorsal and ventral edge of the caudal stalk, feel rough with the hands, the abdomen is small, and there is milky semen outflow from the abdomen after light pressure; the female fish only has a small amount of "pearl star" on the orbital bone and back, and the abdomen is dilated and soft. When breeding, the mature parent fish can be selected and incorporated into the spawning pool according to the plan, or artificial spawning can be induced with hormones to allow them to spawn and inseminate naturally. Because the Wuchang fish eggs are sticky, the eggs can be attached to the artificial nests and then hatched in still water. You can also use artificial egg collection for insemination, then debonding the fertilized eggs, and then artificial hatching with running water. The breeding process and operation method of carp are basically the same as those of carp.

Seedling breeding of Wuchang fish

Wuchang fish fry is small and delicate, so you should be careful when operating it. When fish fry go into the pond, the water quality should not be too fat, and the counting out of the pond should not be too dense and crowded. Spring fillet fry are often raised by graded methods.

After 2-3 days of hatching, the fry gradually moved away from the nest and began to feed on small zooplankton. Therefore, when the fish fry is in the pond, it is necessary to apply appropriate amount of fertilizer every day. It is suitable to put 12 ~ 150000 fish fry per mu for debonding and hatching. When the fry opens its mouth to feed, it is best to feed the cooked egg yolk twice first, and then feed soybean milk for a few days, and then decide the amount of fertilizer according to the fat and thin water quality and the growth of the fry. After 15-20 days of feeding, the fry can grow to 2-3 cm, and then reared in separate ponds.

In the second time, 40 to 50 thousand fire fillet fish were planted in separate ponds, and plankton were mainly cultivated by fertilization. at the same time, soybean cake milk was fed every other day, and some plant fodder such as ladyfish and duckweed were added. After a month or so, summer flowers of 4 centimeters and 5 centimeters can be developed, and the survival rate can reach about 80 percent.

Winter fillet fish species are cultivated from summer flowers, that is, the third level of breeding. The method is basically the same as that of cultivating grass carp. The transparency of the pool water is generally maintained at about 30 centimeters. The stocking density is generally 5000 to 7000 per mu, coupled with 10% of silver carp, bighead carp and herring summer flowers. Can also be in the main culture of silver carp, bighead carp fish pond with 10-20% of Wuchang fish. At the beginning of the pond, feed Laosha, duckweed and soybean cake milk, and then feed purple back duckweed, verticillium verticillata or chopped fresh dry grass. At the beginning of winter, it can generally grow to 1215cm, and the survival rate can reach more than 90%. Grow up fish in the second year.