Breeding Techniques for High Yield Crucian Carp

High-yielding crucian carp, also known as crucian carp, is a new all-female crucian carp cultivated by fish cell engineering technology in the Fish Research Laboratory of South China normal University. Its body color is light and its shape is symmetrical and graceful, which is similar to that of northeast silver crucian carp, and its back is between Pengze crucian carp and high-backed crucian carp. It has the advantages of large individual, fast growth, miscellaneous diet, strong disease resistance and high population yield. it can survive the winter naturally in fish ponds, and it is all female and will not reproduce on its own in fish ponds. It has the advantages of fast production speed, beautiful figure, strong adaptability and fresh meat. Generally speaking, it is the one with the best comprehensive performance among the crucian carp breeds at present.

Culture technology

In order to obtain high yield benefit, culture technology is the key to the main culture of crucian carp in ponds, and attention should be paid to the following aspects:

Correctly distinguish the pros and cons of fish species.

When purchasing crucian carp fingerling, farmers should correctly distinguish the fake and inferior fish species according to the biological characteristics of the main crucian carp species, so as to avoid being deceived and suffer losses, and must choose high-quality fish fry.

Select the main breed

At present, the main cultivated crucian carp are high-yield crucian carp, Pengze crucian carp and Xiangyun crucian carp, among which Xiangyun crucian carp grows the fastest, followed by high-yield crucian carp, and finally Pengze crucian carp.

Design the stocking density of fish fingerling

In order to reduce the cost of breeding, it is best to cultivate large-size fish species by yourself.

1. Crucian carp fry are cultivated in ponds. 8000 ~ 12000 crucian carp summer flowers per mu can reach the cultivated specification of 50g ~ 60g. two。 When the average size of crucian carp adult fish is 50g ~ 60g, it is most ideal to breed 1500 ~ 1800 crucian carp fingerling per mu, and the commercial fish size can reach 350g ~ 400g.

Determine the matching variety

Cultivate large-size crucian carp species not with grass carp and crucian carp, but should choose silver carp and bighead carp, the number should account for about 20% of the main cultured crucian carp, bighead carp account for about 10% of silver carp. The stocking time of matching varieties should not be early, especially the early input of bighead carp has a greater effect on the domestication of crucian carp.

Domestication of fish species

1. It is relatively easy to domesticate in the breeding stage. After domestication, it takes a short time for the domesticated fish species to float and grab food during adult fish culture, so it is easy to manage.

two。 Adding appropriate amount of additives to the feed during domestication can shorten the domestication time and increase the feeding area and quantity of crucian carp.

3. The effect of density on domestication. High density, large number of populations, easy to domesticate. When the density can not be changed, the water level of the pond can be reduced and the density can be relatively increased, which is not only conducive to domestication but also increase the water temperature of the pond and promote the growth of fish.

4. The fingerling of silver carp and bighead carp should be released after the formation of the habit of floating and grazing crucian carp. 5. The water quality during the domestication period should be "thin" rather than "turbid fertilizer". 6. Managers need to be patient and careful when domesticating. Feed size and feeding rate

1. The selection standard of crucian carp feed particle size is "small is not big". Generally, when the size of crucian carp is less than 10 g / tail, the feed particle size is 0.5 mm; 10 g ~ 30 g / tail is 1.5 mm; 75 g ~ 100 g / tail is 2.0 mm; 150 g ~ 300 g / tail is 2.4 mm; above 300 g each tail is 3.2 mm. two。 The feeding ability of fish is directly affected by the size of the fish and the water temperature of the pond, so the feeding rate should be adjusted randomly according to the actual situation.

Prevention and control of fish disease

Although crucian carp has strong disease resistance, hemorrhagic anchor head disease of crucian carp has been found in recent years. Although the incidence of this disease is not high, once infected and allowed to develop, it will also lead to a large number of carp death. The main manifestations of seriously diseased crucian carp are as follows: slow swimming of floating water (fatigue) and pale color; needlelike parasitism can be seen on the abdomen and back of the fish surface (fine scales); there are hyperemia erythema the size of mung bean or pea, the scales of the focus are loose or shedding, the mucus increases, and a few form obvious ulcers. The pathogen is Cyprinus Carpio. The main causes are: first, the pond is not cleared thoroughly or not, and the cause is waiting for breeding; second, the fish species with body surface damage (or careless production operation resulting in fish surface injury) create opportunities for pathogen parasitism.

Prevention method: ① sprinkled 2.5% trichlorfon powder in the whole pond 1 ~ 2 days before crucian carp was planted in the pond. ② small area main culture pond, can sprinkle 90% crystal trichlorfon in the whole pond every half month in the onset season, large area crucian carp mixed culture pond, can carry on trichlorfon hanging basket (bag) around the food farm in the crucian carp growing season, once or twice a month, each time for 2 days. Treatment: in breeding, when there are signs of illness, timely observation and examination, after the diagnosis, the whole pool is sprinkled with crystal trichlorfon and ferrous sulfate mixture.