Summer flowers of spoon-nosed Sturgeon and cultivation of large size fish species

The main results are as follows: 1. Cultivation pond conditions: Sandy bottom soil pond, with an area of 2 to 3 mu, water depth of 1.2 to 1.5 m, silt 15~20cm, qualified source quality, rectangular, east-west direction, length-to-width ratio of 5 to 4, 3 to 3 and 2, flat bottom, convenient entry and drainage.

Equipped with a 1.5~2.2kw single-phase water jet aerator, a 2.2kw single-phase electric submersible pump (4 inch outlet diameter) filling pool water level.

2. Clear the pond and remove the field: quicklime, tea meal, Croton, bleach and Yutenqing 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) clear the pond with quicklime: 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: water depth of 1 meter per mu of 80 jin, fish fry 10 days before lining 15 days. 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) bleaching powder cleaning pond: when the water depth is 1 meter, the dosage of bleaching powder is 25030 jin / mu per mu. After the bleaching powder is dissolved with water, it is sprinkled evenly throughout the 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.

3. Fry cultivation (the fry with 3~4cm/ tail is cultivated into large size fry with 15~25cm/ tail):

1. Fertilizing and improving water quality in ponds: the function of fertilization is to cultivate all kinds of plankton in the water and to produce natural palatable bait after the fry of Sturgeon Sturgeon 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.

2) Fish fry restocking: the lower pond of spoon-nosed Sturgeon fry with 3~4cm/ tail should be on the 5th to 7th day after fertilization, when the occurrence of rotifers and cladocera is at its peak.

From the second day, soybean milk was fed, and soybean milk was ground with 2 jin of soybeans per mu of water surface every day, and fed 2 times a day.

4. Stocking density: generally, the stocking density is 10 ~ 20 thousand fry / mu of spoon-nosed Sturgeon with 3~4cm/ tail.

5. Fish fry feeding: at first, fish fry mainly devoured 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 went down the pond to cultivate bait organisms. Then soymilk feeding method was adopted and soymilk was sprinkled into the pond. Most of them play the role of fertilizer and water to reproduce rotifers.

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 whole pool is sprinkled, and the spilled pulp is like rain and evenly distributed.

After 7 days, they were fed with powdered eel feed or juvenile soft-shelled turtle feed or floating formula feed for fish fry. If the number of rotifers and red worms in the pond is small, fertilizers should be properly applied and clear water should be injected to increase dissolved oxygen to promote the growth of rotifers and red worms. Two daily throws, 8: 00 a. M. and 7: 00 p. M.

6. Fish fry bait cultivation: 3 days after clearing the pond, 500 kg of mature chicken manure or 400 jin of cooked cow manure and 200 jin of green manure were applied per mu, then water was injected into 40~50cm (breeding red worms and rotifers), and strictly filtered with 80-mesh silk mesh cloth to prevent wild miscellaneous fish from entering.

7. Fish fry restocking: spoon-snout Sturgeon summer flower fry are transported from the fry incubation base to the breeding pond, and the fry should be released slowly-put the packing bag directly into the water. After 15-20 minutes, check the water temperature inside and outside the bag with a thermometer. When the temperature difference is within 1: 2 ℃, pour the fry into the pond slowly at the top of the pond.

8. Water level management of the cultivation pond: after 5-7 days of seedling release, the water level of the pond was properly increased every 2-3 days, and 8~10cm was added every time, and the water was gradually increased to 1-1.5 m. 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.

9. 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.

10. 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.

11. Daily management: the main work is to patrol the pond, once in the morning and afternoon, to observe the activities of fish 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: spoon-nosed Sturgeon fry can not tolerate hypoxia, absolutely can not appear the phenomenon of anoxic floating head of fish fry, 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 and aerator should be turned on to regulate the water quality.

12. Domesticate large size seedlings:

A, running water to attract fish: flush with a water pump before feeding, 1-1.5 hours at a time. When flushing, the outlet should keep level with the surface of the pond as far as possible, and the amount of water output depends on the area of the pond. Fish fry have the habit of top water, and the main function of flushing is to gather the fry together for easy domestication. The pump mouth should be as close to the edge of the pool as possible to achieve the best effect of gathering schools of fish.

B, food farm and bait machine installation: set up a round or square food farm in the place where the fish shoal is concentrated at the pump mouth. Four bamboo poles with a diameter of 3~4cm (each with a length of 3mm and 4m) were connected into a square fence. The fence was placed in the pool, and the position coincided with the feeding area of the feeding machine, and then fixed with anchors or piles, and installed the feeding machine.

C, feeding: turn off the pump after 1 hour of flushing and begin to sprinkle an appropriate amount of artificial feed to the food farm by hand or machine. the particle size of the feed should not be too large, usually below 1mm.

D, feeding time: feed 5 times 6 times a day in sunny days, each time for about 30 minutes. The amount of feed depends on the size of the fish, and the feed must be put into the food farm. Generally after 2-3 days of domestication, fish fry can be seen feeding in the semi-aquifer, 5-6 days later can appear the phenomenon of fish fry grazing on the water surface, at this time the domestication is completed.

E. enter the normal feeding stage after domestication: 2 or 3 times a day, after 8:00 in the morning and before 5:00 in the afternoon. According to the feeding condition of fish fry and the weather, the daily feeding amount is 5-6% of the total weight of fish.

13. Daily management of fish fry culture pond: patrol the pond once every morning and evening to fish out the dirt in the pond. Observe the water color, fish activities, pay attention to the weather, water temperature, water color, eating and other conditions, and make detailed records.

14. Water quality regulation of fish fry culture pond: the water depth of fish fry should be controlled at about 50~60cm before entering the pond, and the water quality should be fat and cool. After entering the pond, according to the water color and weather, flush once every 2-3 days, each time 8~10cm, and the water depth should be controlled at 1-1.5m in the later stage.

Start the aerator from 12:00 to 14:00 on a sunny day and stir the pool water to increase dissolved oxygen for 1 to 1.5 hours. Sprinkle 20kg with quicklime per mu every 15 to 20 days to keep the pH value between 7 and 8. In the whole cultivation process, water was injected for 5 times and 7 times, and 8~10cm was injected each time.

15. Fishing of spoon-snout Sturgeon fry: because the spoon-snout Sturgeon is an upper fish and has a mild temperament, the catch rate of pulling the net is higher.

16. Matters needing attention in the process of cultivating summer flower fry:

Spoon-snout Sturgeon fry like to live in fresh, alkaline and sufficient dissolved oxygen water, so quicklime should be often used to regulate water quality, fresh water should be injected, and aerator should be turned on frequently to increase oxygen, so that the pH value of the water body is between 7 and 8, and the dissolved oxygen content is above 6mg/L.