Technique of Shrimp Culture in Net Cage

Aquaculture waters: the waters with low sludge and PH between 7-8.5 need to be selected. Cage production: generally use polyethylene mesh, bamboo floats and other production of appropriate specifications of rectangular cages, and set up anti-escape net. Put in shrimp species: two batches of shrimp can be cultured in cages, the first batch can be put into overwintering shrimp in March-April, and the second batch can be put into breeding shrimp species in the same year from July to August. Feeding management: feed twice a day, do a good job of four diligence, four prevention, field removal work.

First, select suitable aquaculture waters

Shrimp culture in cages will generally choose waters with sufficient sunshine, clean water quality, PH value between 7 and 8.5, water depth of more than 2m, less sludge and flat sediment. It is usually an unpolluted lake branch, river course, reservoir bay, etc. The better the environment, the more suitable for the growth of green shrimp, but also to achieve a better culture effect.

Second, the material structure of the cage

1. The net clothes are generally made of polyethylene mesh and bamboo floats, and ropes and bamboo slices are put on the bottom of the cage. The lower ends of the bamboo tips are tightened and fixed to replace the sunken son. The cage is suitable for building a rectangle with a specification of 10: 6.67: 1.3m, which can reduce the production cost of the cage, increase the exchange of water and improve the ability of wind resistance, which is convenient for selection and capture. The main factor affecting the water quality in the box is the number of mesh in the cage.

2. A thick piece of bamboo with a length of 1.3m is needed on the bamboo frame of the cage every 2-3m, the lower end of the bamboo piece is tightly tied to the bar rope at the bottom of the box, and the upper end of the bamboo piece is tightened and fastened with the bar rope of the escape net. The four corners of the anti-escape net mouth should also be tied with a rope, then tightened with the bamboo tip and fixed on the upper part of the bamboo tip. Close to the four corners of the cage, each hit a bamboo pile, the lower part is in the soil, the upper part leaks out of the water, and then fasten the top five bamboo piles fixed on the cage. Let the cage sink 0.9 m underwater and leave 0.4 m out of the water as an anti-escape net. Every 5 cages are arranged in a row with a box spacing of 4-5m and a row spacing of 5-6m.

3. The four corners of the escape net mouth are also fastened and fastened to the upper end of the bamboo tip. Every 2-3 meters, a thick piece of bamboo 1.3 meters long is tied on the box bamboo rack. The lower end of the bamboo piece is tied with the bar rope at the bottom of the box, and the upper end is fastened with the anti-escape net bar rope. There is a bamboo pile in each of the four corners of the box, the bottom is in the mud, and the upper end is out of the water. Then the top five bamboo piles fixed on the cage are tied with a rope. Make the cage sink 0.9 meters underwater and 0.4 meters above the surface as an anti-escape net. Cage layout, every 5 cages in a row, box spacing 4-5 meters, row spacing 5-6 meters.

Third, put in shrimp species

Shrimp can be cultured in cages for 2 batches a year, and the first batch of shrimp can be reared with overwintering shrimp species, usually from March to April. The quantity is 50-60 000 per mu and the specification is 1000-2000 shrimp fry per kilogram. Autumn culture will be carried out after fishing in the middle of July, that is, the second batch, usually from late July to August. The amount of shrimp species is 8-100000 per mu and the specification is 2000-5000 per kilogram of shrimp fry.

Shrimp species should be weighed and counted with water before entering the box. In the course of operation, shrimp species can not be piled up, do not leave the water for more than 5 minutes, can not be exposed to the hot sun. The shrimp species raised in the same box should be fully released at one time, and the specifications should be uniform. Stocking should be carried out in the evening or morning on a sunny or cloudy day, and if the shrimp has been transported, it should be temporarily reared for 1 day before putting it into the box. When stocking the captured natural shrimp species, the dead seedlings should be removed first.

Fourth, the feeding mode of feed

The main results are as follows: 1. The feed of cage culture is similar to that of pond culture. However, it is necessary to increase the daily feeding times for shrimp culture in cages, generally twice a day, once at 8: 00 a. M., the feeding amount is 1 × 3 of the daily feed quantity, and once after 5: 00 p. M., the feeding amount is 2 times of the daily feed quantity.

2. The powdered bait is generally thrown on the aquatic plants, while other baits are scattered in the whole box. The daily feed intake is 5% of the weight of shrimp in the box. 8%. After putting in the bait, carefully observe the feeding situation of the shrimp. If the bait is eaten quickly, you can increase the amount of bait on the same day and the next day. In addition, when the temperature and climate are suitable and the weather is good, the amount of feed can also be increased appropriately.

3. In general, green shrimp are fed with a compound diet with a feed coefficient between 4.34 and 5.47, and the protein content of the compound feed is required to be more than 35%. The loss of powdered feed is serious and the feed coefficient is high. The use of pellet bait to cultivate green shrimp should be promoted, which can not only maximize the utilization rate of feed, but also increase the yield of green shrimp.

V. Management of shrimp culture in cages

1. Fourth diligence: diligent inspection, diligent patrol, diligent brushing box, diligent maintenance.

2. Four defenses: prevent man-made sabotage and theft, prevent caissons from escaping shrimp, prevent gale from turning over boxes, and prevent pesticide pollution.

3. Get rid of dangerous wild fish and other enemies.

Shrimp species in cage culture for one month, must prevent the invasion of dangerous animals such as river crab, carp, eel, mandarin fish, wheat ear fish, striped fish, etc., once found should be removed immediately. The general way to remove wild fish is to pull up the cage, gather the fish and shrimp in a corner of the cage, and then catch the wild fish or harmful fish by hand and remove them once every half a month or so. Also pay attention to kill water rats, avoid water rats to eat shrimp, water birds will also bring damage, can be driven away with shotguns.