The technique of culturing Sturgeon in cage

Recently, Sturgeon culture in South China has a gradual warming trend, especially in Hainan Province, a large number of shrimp farmers switch to Sturgeon culture. There are various modes of Sturgeon culture. A technique for rapid cultivation of Sturgeon in cage is introduced in this paper. There are many advantages of using cage to cultivate Sturgeon: first, it is convenient to raise and manage Sturgeon; second, it does not need special fishing gear during harvest, and it can start water at one time, and it can also be sold in stages according to needs, which is convenient for the transportation and storage of live fish and is conducive to the regulation of the market; third, it can adapt to the development of mechanized operation and modern breeding technology. The technology of rapid cultivation of Sturgeon cage is introduced as follows:

First, the cage setting Sturgeon rapid cultivation cage is generally made of polyethylene thread woven, the specification is 40 meters × 4 meters × 2.5 meters. The mesh size depends on the specification of the Sturgeon species, which is based on the principle of not escaping fish, conducive to water quality exchange and no leakage of food in the bottom net. if each Sturgeon species of more than 100 grams is released, the mesh is 2Muth3cm. Because it is necessary to feed frequently, it is appropriate for the cage to be open, and the setting mode is frame floating. Cages should be set up in places with good water quality and water depth of more than 3 meters, as well as micro-running water, shelter from the wind, sunny direction, wide water surface and so on. The large reservoir should choose the suitable place of the reservoir bay to set up the cage, and the small reservoir should choose the water area not far from the dam to set up the cage.

2. The most suitable water temperature for the growth of Sturgeon is 20Mel 25 ℃, and the suitable stocking time is the end of May and the beginning of June. The larger the size of the fish species, the better, generally for each fish 100ml 200g, stocking density 35mur40 per square meter. The stocking should be carried out at 6: 00 am, when the difference between the water temperature of fish species and that of the reservoir is small.

Feed feeding Sturgeon cage rapid cultivation is mainly fed with fresh animal bait and artificial compound feed. The protein content of formula feed is 40% Mel 45%. The main raw materials are fish meal, silkworm pupa, meat and bone meal, sausage powder, blood meal, yeast, withered cake, wheat, corn and so on. The reference formula (%): fish meal 37, silkworm pupa 15, blood meal 15, yeast 4.5, withered cake 5, wheat 17, corn 4, additive premix 2, binder 0.5. Weighed according to the formula, crushed and processed into 2Mel 3mm particles for drying and storage. Two points must be emphasized here: first, all kinds of raw materials should be crushed very fine, preferably to reach more than 40 mesh fineness; second, the stability of granular materials in water requires that they can be kept at 1.5 meters for 2 hours, that is to say, good performance adhesives must be used. Of course, if conditions permit, you can also choose commercial feed.

After the fish is put into the box, stop feeding for 2 days in order to adapt to the cage environment. After two days, a small amount or several times of compound feed can be put on the table around the cage (each cage can use 6 bamboo screens with a depth of 0.4 square meters, which are 0.3 cents per mouth, with a depth of 0.2 meters, suspended near the bottom of the box) to induce fish to feed 6 times a day, so that the fish can be fed with artificial pellet feed after 7 days. Then enter the normal feeding stage, feeding twice a day in the morning and afternoon, and the daily feeding amount is generally 4% of the body weight of the fish in the box. Sturgeon have the habit of foraging at night, so the amount of feeding in the afternoon should be more appropriate. How to determine the appropriate amount of feed? The first is to calculate the daily feed consumption according to the daily feeding rate; the second is to check whether there is leftover food and how much it is; the third is to carefully observe the changes of the shadow of the school of fish in the "second layer of water" under the feeding site. Usually at the beginning of feeding, the school of fish grabs food intensively, the shadow is big, the box rolls over, and after the best part of the feeding, the shadow of the school becomes smaller or disappears, and the water tends to calm down, and feeding should end at this time.

Fourth, management measures cages should be guarded by special personnel, and should be inspected many times in the morning, middle, and evening to observe fish and water conditions, especially to prevent floods from washing away cages, to prevent cages from running aground during receding water, to prevent enemy damage, and to prevent silt and slag from sinking cages. In addition, the cage should be cleaned every 10 days or so, especially immediately after the flood, to remove sundries and excessive algae, and to keep the exchange of water inside and outside the cage smooth.

Fifth, the bone plate of Sturgeon body for the prevention and control of fish disease has few natural enemies and a short history of artificial culture, and its epidemic and fulminant diseases are still rare. most of the existing reports are caused by the deterioration of water quality. however, disease prevention work based on water quality regulation and prevention should still be done. Specific methods: soak the cage with raw lime water or bleach powder before launching, and let the algae grow 10 days ahead of time, so as to avoid damage to the skin of the body surface after the fish species enter the box; disinfect the fish first when entering the box, soak them in 3% Kuk 4% salt water for 15 minutes, and fish that are killed or injured should be fished along with them to prevent pollution and cross-infection. Sprinkle the box and its adjacent waters with 3kg of quicklime every 15 min 20 days, once a day for 3 consecutive days; the residual bait must be removed every day, the table must be washed and dried, and the table should be sprinkled with quicklime water regularly to enhance the feeding of Sturgeon and reduce the incidence of fish disease. If rotifer, oral filariasis and oblique tube disease occur during the feeding period, potassium permanganate 2 mg / L or copper sulfate 75 mg / 1 can be used for prevention and treatment.