Pelteobagrus fulvidraco, as one of the traditional famous and excellent aquaculture species, is favored by consumers for its delicate meat, less spiny meat and high nutritional value. In recent years, with the success of artificial propagation of seedlings, large-scale aquaculture development is faster. This article introduces the net box culture technology in the lake.
First, aquaculture water
The net box set up a water area of more than l00 acres, the requirements of the water body dissolved oxygen in the long term more than 4 mg / liter, water transparency in 40-50 centimeters, the water body is not polluted. The net box specifications 4 meters long, 3 meters wide, l.2 meters deep. Mesh 5?8 mm, polyethylene knotless mesh, net box on the shade net shade, leaving 0.5 square meters in the middle of the bait mouth, net box upper mouth made of moso bamboo frame, moso bamboo every o.5 meters drilled holes, inserted 60 centimeters long diameter 8 mm round steel, used to fix the upper mouth of the net box. The bottom of the net box with stones as a sinker to fix the lower mouth. Before the net box in the water to check the net clothes have no damage, in the put seedlings before 7 days underwater immersion, such as the net box on the adhesion can only be released when the seedlings. The net box is set up in the diameter of l meters of food table, food table requirements can be moved up and down freely, easy to observe the fish eating situation and check the physical condition of the fish.
Second, the stocking situation
The specification of the casting of the fry should be neat, disease-free and injury-free. The selection of wild-caught fry should be careful, because most of such fry are caught with cages and other netting, the fry are trapped in the net for a long time, serious injuries, and a high mortality rate after placement. Fry are soaked in l% table salt and l% sodium bicarbonate for 30 minutes before release. The stocking specification was 280 fishes/kg. Stocking density according to the growth of three times sparse, the first stage March l0 put, the density of l000 tails per cubic meter. In the second stage, on June 20, the density was adjusted to 500 tails per cubic meter when the fish size grew to l40 tails per kg. In the third stage, on July 25, when the fish size reaches 80 tails per kilogram, the density is adjusted to l50 tails per cubic meter until it is raised into commercial fish. Fry in the water after continuous medication 3?5 days, with povidone iodine 0.5ppm due to the large body of water, each box of wine medicine time control in more than 20 minutes.
Third, feeding management
1, feeding: feed for self-mixing, crude protein content of more than 45%. 67% of the fish and 33% of the powdered material mixed into soft particles, feed size according to the specifications of the fish constantly adjusted, particle size 3 a 6 mm. Fresh fish or chilled fish should be used for minced fish, which should be sterilized before processing. The fineness of the powdered material is required to be above 20 mesh. The formula is: 60% soybean meal, 9% vegetable meal, 20% corn, 5% bran, 5% powder, special premix l%. Feeding 3 times a day, morning, afternoon, evening 1 time, evening feeding accounted for 60% of the total amount of feed throughout the day, the daily feeding rate of 5% -7%. Fry put in 3 days after the start of the bait, each bait before the knocking sound, a period of domestication will form a conditioned reflex. Start feeding the feed
On the food table, check after one hour, according to the remaining feed and the number of fish on the feed table to decide the amount of feeding. If the number of fish on the table is high, the amount of feed can be increased. After l0 days of baiting, the fish form the habit of eating at regular intervals, and the feeding method is changed to slowly splashing wine feeding, gradually leading the fish to the upper layer of the water, and eating 20 centimeters below the surface of the water, and the feeding time is about 30 minutes each time.
2, anti-escape, ventilation management: check the net box once a week, because the yellow catfish dorsal and ventral fins have hard spines, in the stress reaction when the fins are open, jagged hard spines are easy to hook the net, struggling hard to lead to netting breakage, escape accidents. If the mesh is thick, it is easy to be attached by moss and other algae, the mesh is blocked, and the water inside and outside the box can not be exchanged normally, resulting in the floating head of the fish lack of oxygen. Algae attachment should be cleaned in time, especially in July and August, we should pay attention to cleaning the net box. Due to the thick mesh, wind resistance, in the windy and rainy season to reinforce the net box, to prevent the wind from blowing over.
3, disease prevention: Pelteobagrus fulvidraco dorsal fin spines and pectoral fin spines open when stimulated, due to the absence of scales to protect, and has the habit of clustering, the body surface is very easy to be injured. Use povidone iodine to bathe the fish before putting them into the tank. The drug was used 3 times continuously after the fish species were placed in the box, and then every l5 days for 2 days each time. Add anti-stress drugs to the feed. The incidence of hemorrhagic disease is higher in the high temperature season, the main symptoms: yellowing of the fish body surface, increased mucus, pharyngeal skin breakage and congestion, abdominal expansion, anal redness and swelling, the fin base is congested, fin ulceration, and abdominal fluid accumulation. The disease is fierce and spreads rapidly. The mortality rate is up to 30% if the disease is not handled in time. Found that the decline in fish intake, immediately check, diagnosed as hemorrhagic disease, splash wine anti-storm spirit lppm, used for 5 days, internal florfenicol, add 0.2 grams per kilogram of feed, while taking vitamin K, etc., 5?7 days for a course of treatment.
Fourth, breeding results
March l0 l3 to l0 month 30, after 230 days of feeding, l0 end of the catch and sell. 8 nets 96 square meters, put 65 kg of fish species, l8200 tail, the sale of the average specifications up to l05 grams, the total harvest of l7836 tails, the production of l873 kg, per square meter of fish production l9.5 kg, survival rate of 98%. The average price of Pelteobagrus fulvidraco was 30 RMB/kg, and the total output value was 56l90 RMB. Production costs: feed costs l2500 yuan, fish seed costs 3900 yuan, net depreciation, medicine costs 3000 yuan, personnel wages 4000 yuan, profit 23400 yuan, an average of 243 yuan per square meter profit, input-output ratio of l: l.7l.