Summer Flower of Silver Carp and cultivation of older size Fish

Pond selection

The area of silver carp fry culture pond is 3 to 5 mu, rectangular, east-west, length-width ratio 5, 4, 3, 2, average water depth 1.2, 1.5 meters, slope ratio 1, 1, 1.5, bottom flat, loam, silt thick 15~20cm, easy to enter and drain.

The area of silver carp fingerling culture pond is 1015mu, rectangular, east-west, the ratio of length to width is 5, 4, 3, 2, the average water depth is about 1.8, 2.5 meters, the slope ratio is 1, 1, 1.5, the bottom is flat, loam, silt thick 15~20cm, easy to enter and drain.

Clear the pond and remove the wild

Quicklime, tea meal, Croton, bleach and fish rattan clear can be used alone or mixed. In ponds with serious fish disease, bleach or quicklime is used to clean the ponds, or tea meal plus a small amount of quicklime to improve water quality, which plays a certain role in improving the survival rate of fish fry and fry.

1. Quicklime pond cleaning: drain the pond water to about 10~20cm and sprinkle it evenly with lime paste. The dosage is about 100kg / mu. Fish ponds with inconvenient water sources can be filled with water, with a water depth of 1 meter and about 250 kilograms of quicklime per mu.

2. Tea meal cleaning pond: the water depth is 1 meter and 80 jin per mu, and the fish fry is applied 10-15 days before lining. When the water temperature is low, the toxicity disappears slowly, and when the temperature is high, it disappears quickly. First beat the tea meal into blocks, put it into a wooden stick or water tank, soak it with water and soak it for one day and night when the water temperature is 25 ℃. Increase the amount of water during application and sprinkle evenly throughout the pool.

3. Bleach cleaning pond: when the water depth is 1 meter, the dosage of bleach is 250.30 jin / mu per mu. After the bleach is dissolved with water, it is sprinkled evenly in the whole pool immediately. The chlorine content of bleach should be about 30%. Bleach cleans the pond for 4 to 5 days and the fish can be released. The cleaning of bleaching powder is related to the fertility of pool water, and the effect of water and fertilizer is poor.

Fish fry cultivation

1. Fertilizing and improving water quality in the pond: the function of fertilization is to cultivate all kinds of plankton in the water and produce the open bait after the fry goes down the pond.

After 2 or 3 days of disinfection, 500 jin of fermented manure was applied per mu, or 2000 jin of green manure per mu or 20 jin of urea + 20 jin of phosphate fertilizer per mu were used to cultivate plankton. Rotifer and plankton multiplication reached the peak after 5 days of fertilization.

Fertilization effect: after fertilization in the pond, the first dominant population of plankton was related to the nature of fertilizer. With the application of organic fertilizer, phytoplankton-dinoflagellate and cryptoplankton, zooplankton-tail caterpillar and peripheral caterpillar first appeared in large quantities. Diatoms, Scenedesmus and bouncing worms became the main populations when applying inorganic fertilizer.

When the amount of fertilizer application is large, some species of green algae and cyanobacteria will develop greatly, and when the amount of fertilizer application is small, many species of diatoms, such as spindle diatom and disk diatom, will become the dominant species.

Zooplankton reached the peak 4-5 days after fertilization. The first large number of zooplankton are protozoa and rotifers, followed by Cladocera, followed by copepods.

After fertilization in the pond, if the water is light green brown, algae, protozoa and rotifers multiply in large numbers, and cladocera is just beginning to appear, which is most suitable for the growth of bighead carp fry.

2. the time of fish fry in the pond: silver carp fish fry in the pond should be 5 ~ 7 days after fertilization, when the occurrence of rotifer and cladocera is at its peak.

Feed one cooked egg yolk for every 100000 fry to feed them into the pond. From the second day, feed soybean milk, grind soybean milk with 2 jin of soybeans per mu of water every day and feed it 2 times for 3 times.

3. Fish fry restocking: the fertility should be moderate when entering the pond. The larvae in the lower pond should be put into the fry box and fed with cooked egg yolk. 100000 fish should be fed 1 cooked egg yolk. Feed the cooked egg yolk according to the following steps:

1) boil the egg yolk for a long time, wrap the egg yolk in 60-purpose nylon sieve silk, shake and filter in a basin filled with water, do not pinch it by hand, and make the yolk particles precipitate out of the water from the mesh.

2) pour the yolk water evenly into the fry box with your fingers. Half an hour later, you can see that there are yolk particles in the intestines of the larvae (commonly known as flower sausages).

3) put the larvae into the pond after keeping them in the fry box for 3 hours.

4. Stocking density: generally, the stocking density is 15 ~ 200000 fish / mu. If the fry grow to full-length 2~2.5cm, the stocking density can be increased, up to 25 ~ 300000 fish / mu.

5. Fish fry feeding: at first, the fish is too small to mainly devour rotifers, small cladocera and other plankton in the water. The fish fry should be fertilized into the pond, and organic fertilizer should be applied before the fry goes into the pond to cultivate bait organisms, and then soymilk feeding method is adopted. Soymilk is sprinkled into the pond, some of which are fed by fish fry, and most of them play the role of fertilizer and water. The amount of feed generally fed 4 kilograms of ground soybean pulp per mu every day, which increased to 8 kilograms after a week, and mastered the dosage according to the water color, the ratio of water to beans was 30:1.

Fish fry under the pond within 5-7 days, mainly to feed soybean milk, soybean milk should be swollen when grinding, and soybean dregs should be removed after grinding. When feeding, the paste should be sprinkled twice along the edge of the pool, and the spilled pulp should be like rain and evenly distributed. After 7 days, they were fed fine flour, rice bran, wheat bran and other powdered concentrate feed. Two daily throws, 9: 00 a. M. and 4: 00 p. M.

After 25 years and 30 days of cultivation, the fry size can reach more than 3.3cm, and the daily feeding amount is 1520% of the fish body weight.

6. water injection by stages: adding new water into the pond by stages to increase the water level of the pond, so as to increase the oxygen content in the water, improve the water quality, expand the activity space of fish fry, and accelerate the growth of fish. Promote the reproduction of plankton and increase live bait.

When the fry entered the pond, the depth of the pond was about 0.6-0.7 meters. After 7-15 days of culture, the depth of the pond increased to 1 meter. When incubated for 20-30 days, the depth of the pool increased to 1.2 meters. After 40 days of cultivation, the depth of the pool increased to 1.5 meters.

When injecting water, a dense net is used to filter wild miscellaneous fish and pests at the inlet, while avoiding the flow of water directly into the bottom of the pool to muddy the water.

7. Water quality regulation: when releasing seedlings, the transparency of pond water is below 30cm, and then appropriate topdressing is applied to control the fertility of pond water. The transparency of pond water is controlled around 25~30cm in summer and around 35cm in autumn.

8. pond patrol management: after the fry pond, patrol the pond three times a day to achieve "three checks" and "Sanle".

Check the floating head of fish fry in the morning, frequently catch frog eggs; check the activity of fish fry in the afternoon, remove weeds on the ridge of the pond; check the water quality in the evening, make records, and arrange bait, fertilization and water addition work the next day. Check the occurrence of the disease at any time and carry out prevention and control in time.

9. Daily management: the main work is to patrol the pond, once in the morning and afternoon, to observe the fish activities and the changes of water color and water quality, to take timely measures and determine the amount of bait when problems are found, and to remove weeds on the edge of the pond in time. In addition, attention should be paid to the cultivation and regulation of water quality, so that the pond water is rich in palatable natural bait and sufficient dissolved oxygen through reasonable water injection and fertilization.

Diligent observation, prevention of floating head, prevention of fish disease: fish breeding stage, sooner or later to patrol the pond. In order to prevent the pool water from anoxia caused by weather changes, new water should be injected frequently to regulate the water quality.

10. Feeding technology and feeding amount: after the body length 2~2.5cm, the powder compound feed is fed, and the daily feeding rate is 1015%.

11. disease control: the main diseases in the seedling cultivation stage of bighead carp are parasitic diseases, such as rotifer, fish lice, anchor flea and so on.

Control method: regularly sprinkle with crystal trichlorfon and copper sulfate in the whole pool to make the pool water concentration up to 0.3g/ cubic meters, and then sprinkle it again the next day to prevent and cure.

12. Exercise and separate ponds: after 20-25 days of feeding, bighead carp seedlings grow to about 3cm and should be reared separately. Before going out of the pond, the summer flower fry should be trained for 2 or 3 times. Make the fish species in the dense process, increase the adaptability of the fish body to hypoxia. Make the fish "sophisticated" strong, can withstand separate culture out of the pond, and avoid producing a large amount of mucus and feces to pollute the water quality in the process of transportation, and improve the survival rate of transportation.

1), pull the net for the first time: gather the summer flowers in the purse seine and check their physique. Then put it back in the pool. Because the fish is tender, the operation should be careful.

2), the second time to pull the net: every other day, carry on the second time to draw the net. After collecting the fish, let the top water enter the cage automatically. Put it back in the pool in two hours. If it is for self-feeding, then after 2 times of pulling the net into the box, separate cultivation can be carried out.

3), the third time to pull the net: after the second time, the net can be pulled for the third time every other day, and the fish can be "suspended" for one night in the cage in the pool with cleaner water quality, and the long-distance shipment can be carried out in the early morning of the second day.

Exercise fish fry must choose fine weather, in the morning when the fish do not float head. The operation of pulling the net to drive the fish should be slow, so as not to hurt the fry. Don't let fish stick to the net when you close the net. After the fish is in the box. The box should be washed immediately to wash away the excrement and dirt of the sticky net, so that the water body inside the box and outside the box can be unblocked, so as to prevent the death of fish fry due to lack of oxygen in the box.

13. Physical and chemical indexes of water body during fry culture period:

1) oxygen consumption of organic matter: under the condition that there is no lack of dissolved oxygen in pond water, the oxygen consumption of organic matter is high, and the survival rate of bighead carp fry is also high. Before the fry goes into the pond, the oxygen consumption of organic matter is more than 30 mg / L in order to ensure the fertility needed for the growth of plankton.

Fish fry after entering the pond, a large amount of plankton intake, continuous consumption of organic matter, we should continue to apply fertilizer. The amount of fertilization should be small, the times should be more, and it should be applied every 2-3 days. Part of the spilled soymilk is cultivated for zooplankton, part is used as organic fertilizer, and only a small part is directly used by the larvae.

2) dissolved oxygen: the amount of dissolved oxygen in water is closely related to the survival of fish fry. When the dissolved oxygen in water drops below 2mg/L, the fish fry will have floating head. The amount of dissolved oxygen in water needed for the normal growth and development of bighead carp fry is 4.5mg/L, and when it is reduced to 1.7mg/L, the respiration of bighead carp fry is inhibited. In the process of production, the fry of bighead carp floated slightly from pre-dawn to 1-2 hours after sunrise, indicating that the water quality was too fat and should not be fertilized with bait.

3) pH value: when the pond is cleaned with quicklime, the pH value and hardness of the pond water are high, and all rotifers die, but it is harmless to rotifer winter eggs. When the pH value is below 10, a large number of rotifer winter eggs can germinate. After 8-10 days of pond cleaning, the efficacy of lime disappeared, pH decreased below 9, phytoplankton began to multiply in large numbers, and the amount of dissolved oxygen in pond water increased, often reaching saturation. At this time, a large number of rotifers appeared, and the fish fry should go into the pond in time.

Cultivation of one-year-old large size fish species of silver carp

The process of cultivating adult length 20~25cm of summer flowers with body length 2.5~3.3cm is called one-year-old large size fish breeding. The method of interculture is adopted, generally, the summer flower fry of 2.5~3cm is 600-1200 per mu per mu.

1. Preparation before stocking: the area of the fish pond is larger, generally 10-15 mu, the water should be deeper, generally 1.8-2.5 meters. Organic fertilizer should be applied to culture before stocking, and proper amount of base fertilizer should be applied to silver carp, and rotifer should go down to the pond during the peak period.

2. Summer flower stocking: the stocking time is generally from May to June, and there are monoculture and mixed culture, generally using mixed culture, because at this stage, the habits of fish are gradually different, and the requirements for the external environment are also different. mixed culture is carried out according to the habits and adaptability of all kinds of fish, not only to give all kinds of fish a suitable growth environment. At the same time, it also gives full play to the utilization rate of water body and the more economical utilization of food. There are generally 2-3 kinds of mixed culture in fish ponds, with a little silver carp and carp.

3. Feeding and management: at this time, silver carp mainly takes plankton as the main food, the pond water is required to be fertile, and the plankton biomass is more. In addition to applying basic fertilizer before stocking, summer flowers should also be applied green manure and cooked manure after stocking, combined with regular injection of new water to keep the water brownish green. During artificial feeding, we should pay attention to the "four fixed" principles of timing, positioning, quality and quantity, so as to improve the utilization rate of bait and reduce the feed coefficient.

Fish fry and fish fry transportation

In the process of transporting mackerel fry and fry, no matter what method is used, the operation must be meticulous. Pay attention to the following aspects:

1, the fry is physically strong, the fry room is inflated (long waist point), the mouthparts are open, swimming is lively, and it can be shipped. The amount of oxygenated transport in nylon bags is about 80% of that of the transport box.

2. The water quality is fresh and non-toxic and the dissolved oxygen content is high. The water of rivers, lakes, reservoirs and ponds can be used, and the water with colorless transparency and low mud content should be selected. Tap water should be dechlorinated and stored for 24 hours before use. Use cold water in summer.

3. Before the fingerling is transported, the fish should be trained by pulling the net to remove feces. The body is strong, reduce mucus secretion, in order to improve the survival rate.

4, pay attention to the temperature balance, the temperature difference should not be ±2 ℃, after arriving at the destination, you should first wake up the fish in the box, and feed the fish fry with cooked egg yolk an hour later. 100000 fish fry are fed with one egg yolk. After seeing the fish fry sausage (swallowing the egg yolk into the intestine), wait another hour before putting the fish into the pond. For the fish fry in nylon bags and transport boxes, put them into the water before leaving the box to make the internal and external water temperature consistent. Then open the nylon bag or transport box, pour water into the pond, put the bag into the box, and let the fry (fry) swim out on their own.