Seedling cultivation techniques of red-eyed trout

1. The cultivation pond: the area is 3 to 5 mu, the water depth is 1.8 to 2.2 meters, and the pond is disinfected and filtered with bleach.

2. Water quality cultivation: 150 kg of fully fermented chicken manure was released 3-5 days before the fry went into the pond, the water was oil-green, the water quality was refreshing, and the transparency was about 30 cm. After the fish fry is put into the pond, it is used with soybean milk to maintain good water quality. Because the mouth of red-eyed trout is small, it can only feed on small plankton, so the base fertilizer should not be applied too early.

3. Spray stocking: "test the water" one day before seedling release to detect whether the toxicity of pond-clearing drugs disappears. At the same time, pull frog eggs, tadpoles or other enemy organisms out of the whole pond with a dense eye net for 1 or 2 times. The seedling release time is chosen in the sunny morning; if you buy spray, you should first soak the nylon bag in the pool water for 0.5 h to adjust the temperature difference. Red-eyed trout spray is very delicate, the operation should be very careful, the temperature difference of seedlings should not exceed 2 ℃. The stocking density is determined according to the pond conditions and the level of culture technology, and generally 10 ~ 150000 flocks can be stocked per mu.

4. Stocking density: under normal circumstances, fish fry (spray) can be reared from full-length 0.7~0.72cm to full-length 1.7~3.0cm summer flowers, and 15 ~ 200000 fry can be released on the effective water surface per mu.

5. Feeding management: soymilk was sprinkled in the whole pond on the same day when Shuihua went to the pond. 4 jin of dried soybeans are used on each mu of water surface every day, and then sprinkled in the whole pool after twice grinding. In the middle and later stages of summer flower cultivation, appropriate amount of fertilizer is applied according to the water quality, and the amount of soybean milk is gradually reduced, while the feeding amount of powdered concentrate (such as secondary powder, fine bran, etc.) is increased, generally 4 jin per mu of water surface every day to ensure that fish fry get sufficient feed. After 10 days, the addition of soybean meal and secondary powder was mixed with water, and then fed intermittently along the waterside, and gradually reduced the amount of soybean milk. Then the micro-particle floating mixture was fed step by step, and all the micro-particles were used after five or six days, once in the morning and once in the afternoon, and the feeding amount was basically finished in 20 minutes. Note: from the time the fry (spray) is put into the breeding pond, soy milk can be sprinkled carefully and evenly for the first time in 2 hours. The pond where the fry is released in the morning should be fed 2 times or 3 times on the same day, and the pond where the fry is released in the afternoon should be fed with soy milk once or twice on the same day. From the morning of the second day, three times a day, that is, 8: 9 a.m., 12: 00 p.m. to 1: 00 p.m., 4: 5 p.m., sprinkle evenly on the whole pond. After spilling soybean milk continuously for 3 days, depending on the water fertility and biomass (especially the number of rotifers), the daily amount of soybean milk can be reduced appropriately. If the aquaculture pond water has become fat, you can change the daily soymilk spilling times to 2 times, that is, 9: 10 a.m. and 3: 4 p.m. Fish fry (water spray) after 10 to 12 days of soy milk water cultivation, its fish body has grown to the full length of 0.8~1.2cm, at this time should promptly feed artificial preparation of powdered materials (such as mature oil flour, oil fine wheat bran, oil fine rice bran, etc.), when the weather is good, breezy or no wind, sprinkle appropriate amount of powder around the pond with your hand. If there are fish floating to eat after sprinkling, the feeding times and feeding amount should be increased appropriately. It is appropriate to eat all the powder in 20-30 minutes each time. When fish fry are cultivated for about 20 days, the amount of soybean milk should be reduced timely and appropriately according to the water quality in the pond. At the same time, the powder feed fed every day was changed into artificial particle feed which was broken and with powder particles. The daily feeding amount is 412 jin per mu of effective water surface.

6. Water quality control: attention should be paid to the management and control of water quality during the whole nursery period. generally, with the growth of fish fry, new water is often injected to raise the water level slowly. When the water quality is fatter in the later stage of seedling cultivation, the water level should be increased to the highest level to ensure that the water quality is "fat, lively and cool". Daily management should persist in patrolling the pond twice a day in the morning and evening, carefully observe the activities of fish fry, food intake and changes in water quality, and solve the problems in time. With the individual growth of fish fry, the feed feeding is increasing day by day, and the oxygen consumption factors in the culture pond are also gradually increasing. In this stage of breeding and cultivation, it is necessary to strengthen the management of water source and water quality. In order to expand the culture space, increase the water capacity of the breeding pond and regulate the water quality, it is necessary to timely increase the water level of the pond, which can be used to improve the water quality environment of the culture pond, increase the dissolved oxygen of the pond water, and keep the pond water fat and fresh. Add water once every 5-7 days, 5-10 cm each time. Use biological bacteria once every 15 days to keep the water quality fresh, with a transparency of 25cm, dissolved oxygen of 4mg / L and a pH of 7.0mg / L.

7. Separate pond stocking: after 25-30 days of cultivation, the water spray can generally reach 3~3.5cm in body length. At this time, it should be sold or divided into ponds in time and transferred to the stage of fish breeding. If summer flowers want long-distance transportation, they still need to go through 2 or 3 net-pulling exercises before going out of the pond, but be careful to avoid trauma as far as possible, so as to improve the survival rate of getting out of the pond and transportation. After pulling the net and dividing the pond, continue to feed the floating material, and match it with a small amount of Wuping. In the whole process of cultivating summer flowers from fish fry, it is necessary to strengthen management. It is necessary to persist in patrolling the pond in the morning and evening, and carefully observe whether there are any abnormal phenomena in the activities and feeding behavior of the fish in the pond, and whether there are changes in water quality and water level. once abnormal problems are found, effective measures should be taken in time to solve them. Note: as the temperature and water temperature are both high at this time, the red-eyed trout in the summer flower stage is very delicate, sensitive, good at jumping and swimming fast, so it should be careful and meticulous in the whole operation of fish training, moving net and selling out of the pond. try your best to avoid fish injuries so as to improve the survival rate of out-of-pool, turn-to-pond, sales and transportation.

8. Autumn fillet breeding: from summer flower culture to autumn fillet species, the effective water surface per mu can match not only 1.2 ~ 15000 summer flowers of 2.0~3.0cm, but also 200 silver carp in the same year, but not with other species. Its breeding is mainly fed with powder → broken bait and → bait.

1) feeding: at the initial stage of summer flower stocking, the bait must be palatable, preferably in the form of powder and floating powdery small broken bait. Every 10,000 summer flowers were fed 300 million 350 g per day, and the feeding amount was increased once every 5 to 7 days, and the feed was gradually increased according to 57% of the total feed in the previous 5 or 7 days, so that the daily feed of pond fish accounted for 140.7% of the total weight of pond fish, and the daily feeding was 3 times per day, that is, 7: 8 a.m., 10: 11 p.m., 1: 00 p.m. and 4: 5 p.m.; or 7: 8 a.m., 11: 12 p.m. and 3: 4 p.m. When the summer flower is above 5cm, the daily feeding should be changed from 3 times to 3 times, that is, every day at 8: 9 a.m., 12: 1 p.m. and 4: 5 p.m., it can also be changed to feeding pellet baits once in the morning and afternoon, that is, 8: 9 a.m., 2: 3 p.m. and 5: 6 p.m. The daily feed intake of concentrate is 70.4% of the total weight of pond fish. According to the weather, water temperature, water quality, the level of dissolved oxygen, the activity of pond fish, feeding behavior and so on, the daily feeding amount should be mastered flexibly. It is appropriate to start feeding the fish each time until all the bait (except duckweed) is eaten within 50 minutes. The daily intake of green fodder depends on the feed source, but for fresh duckweed, the maximum daily feed should not exceed 12% of the total weight of pond fish, and it is better to feed it every evening.

2), water quality regulation: in the whole process from summer flower breeding to fish fingerling, the water quality of the culture pond should always be kept in good condition. in general, fresh water should be injected every 10-15 days, and the amount of water each time should not be less than 10cm. In case of sudden change, it is necessary to increase water injection or water exchange, especially in the midsummer season when gas and water temperatures are both high, the water level of the pond should be injected to the highest point in order to expand the culture space and increase the dissolved oxygen content in the pond.

3) Daily management: the period from summer flower breeding to autumn fillet fish species coincides with the midsummer season of changeable weather and unstable climate. During this period, we should attach great importance to the daily management of aquaculture ponds:

A. it is necessary to control the water level and quality of the pool, and timely add new water or replace part of the old water.

B. It is necessary to keep the dissolved oxygen in the water body of the culture pond above 4mg/L.

C, to see the day to feed the fish, in the number of bait, we should not only grasp the "four fixed" principles, but also pay attention to observe the weather changes, look at the sky, look at the water, feed the fish appropriately. Red-eyed trout is sensitive and active, has a strong ability to grab food, and is gluttonous, and its oxygen consumption rate is higher than that of other conventional fish. therefore, it should not be allowed to spend the night full in muggy and rainy weather.

D, it is necessary to start the machine to increase oxygen at the right time, strictly prevent the floating head of the pond fish, adhere to the work of patrolling the pond, patrol the pond in the morning, middle and evening every day in the whole process of raising, and carefully observe the changes of the pond water and whether there are any abnormal phenomena in the activity of the fish.

By using the above-mentioned method, the survival rate can reach more than 90% from the summer flowers to the autumn and winter of the current year, the average total length of the fish species can reach more than 12cm, the average tail weight can reach more than 40kg 60g, and the fish seed yield per mu can reach more than 1500 jin.

9. Winter fillet fingerling cultivation: it is basically similar to summer flower cultivation, but the stocking density is controlled at about 10, 000 tails / mu. In addition, with the continuous growth of seedlings, it is necessary to feed compound feed and appropriate amount of green feed (such as duckweed, verticillium verticillata, etc.). As long as the feed is sufficient and the water quality is good, the specification of summer flower cultivation of red-eyed trout can reach more than 12cm by the end of the year. it can be used as a species for fish cultivation in the following year.

Red-eyed trout seedling stage has a faster growth rate, after 70-80 days of breeding period, the fish size can reach more than 10 cm, the survival rate is more than 90%.