Green Peanut Factory Seedling Test
We are manufacturer for kinds of Edible Fungus, main product is morchella esculenta. Edible Fungus Edible Fungus,Mushroom Edible Fungus,Organic Edible Fungus,Shiitake Edible Fungus Chengdu Minghe Agriculture Co.,Ltd , http://www.cdmhny.com
Key words: shrimp; nursery; egg holding rate; hatching rate; cultivating rate CLC number: S966.12+2.2 Document code: B Article ID: 1003-1721 (2002)02-0005-02
Green shrimp (Macrohrachium nipponense) scientific name Japanese Macrobrachium, belonging to the arthropod, crustacean, decapoda, long arm shrimp, Macrobrachium, is one of China's expensive aquatic products. In recent years, due to overfishing, the natural resources of green shrimp have been declining. Market prices have been rising year by year, and supply exceeds demand. Artificial breeding is imperative. The development of shrimp culture must first solve the seed supply problem. For this reason, in 2000, we used the original crab breeding plant to conduct a trial of industrialized nursery cultivation of shrimp and successfully cultivated it. In 2001, on the basis of improving the seedling raising technology, repeated tests were conducted. The 2001 test results are reported below.
1 Materials and Methods
1.1 Breeding conditions The nursery is a artificial brackish water nursery facility for the original crab, including a storage tank, a monocytic algae cultivation pond, a rotifer breeding pond, an indoor nursery pond, and a broodstock holding pool. Among them, nursery ponds, single-cell algae and rotifer breeding ponds are located in a 1000m2 totally enclosed glass top greenhouse plant. There are also 2 kW large Roots blowers and 2 boiler heating facilities. Water for nursery was introduced from Lake Plano (660hm2).
1.2 Broiler rearing
1.2.1 Temporary pool broodstock holding pool 8 with an area of ​​l60m2 and a depth of 1.5m outdoor cement pool. The influent water is filtered with a 100-mesh sieve. The masonry, rubble, and bamboo branches are used for concealment. The water is placed in four corners. Peanut or water hyacinth.
1.2.2 Parents Select broodstock from the natural waters of Dongting Lake. The physique is robust and the limbs are complete. The specifications are: the length of the carcass is more than 3cm; the tail weight is 4.2g, the carcass length is more than 4cm, and the tail weight is 5g.
1.2.3 Management 1 8:oo every morning and 5:30 pm each time, feeding 8% of the weight of broodstock, 40% of the day in the morning, 60% in the afternoon, according to the shrimp eat The situation is adjusted. The bait is mainly soybean meal, corn flour, fresh small fish, snail meat and cooked egg yolk and other high-protein foods to meet the nutritional needs during the breeding period; 2 every morning before the feeding, the sewage is sucked once and the fish is killed. Shrimp, change the water once a week, every day with a stream of water rushed broodstock l ~ 2h, so that the pool of water to form a rotating flow, stimulate broodstock peeling, mating, holding eggs; 3 each pool equipped with 420 W small air pump l Taiwan, inflatable Oxygen, dissolved oxygen is maintained at 5mg/L or more; 4 lime water per week splash 10g/m3 to adjust water quality. Supplement Ca2+ concentration, prevent disease with lg/m3 oxytetracycline or furazolidone every 5 days; after 5 oviparous shrimp appear, check the egg development regularly every day, when the egg becomes transparent, the heart rate can reach 180 times/min. It indicates that imminent emergence will occur and the egg-holding shrimps will be immediately transferred to nursery ponds.
1.3 Biofeeding
1.3.1 Unicellular algae cultivation tanks are 5 indoor 4m2ml m cement tanks. The treated water is introduced into the storage tank. The depth of the water is first controlled at 0.5m. The nutrient salts sodium nitrate, potassium dihydrogen phosphate and iron citrate are applied. And sodium silicate, so that its concentration in the water were 40,4,0.4,lg/m3, the water temperature was controlled at 18-22 °C, and then introduced and cultivated, after 5-6d, these 4 kinds of nutrients were applied, and the concentration was halved. And gradually deepen the pool water. When the density of unicellular algae reaches 1800-2000 million/mL, it is picked up and fed. The algae species is Cyclotella sp.
1.3.2 Rotifer culture The rotifer breeding pond is 5 indoor cement ponds of 4m2ml m. First, the monophyletic algae should be cultured as the basic bait for rotifers. When unicellular algae reached a certain density, rotifer species were introduced. The rotifer density of 10-14 days could reach 40-50/mL. With the increase of rotifer population, the basic food was reduced, and soybean milk was fed twice a day (15g dry weight). /m3). The rotifer species are Brachionus rotifers and cysticercus rotifers.
1.3.3 Freshwater, freshwater cockroaches are mainly small branches and copepods. They are collected from freshwater ponds, disinfected and rinsed for use.
1.4 Cultivation of larvae
1.4.1 Nursery pond preparation The nursery pond is 10 indoor cement pools of 15m2m1.5m. Air stones are arranged in the pool and the density is 4/m2. The amount of aeration can be arbitrarily adjusted. Above the nursery pond is covered with a shade cloth to adjust the light. The nursery water is introduced from the storage tank and an appropriate amount of water containing the monocytic algae is added.
1.4.2 The seedlings will be transferred into the nursery ponds for the development of good egg-holding shrimps. In order to achieve the concentration of seedlings, the juveniles are neat and tidy, and generally more concentrated egg-holding shrimps are discharged in a pool. When the larvae in the pool reach the predetermined density (500,000 pigs per m3), the larvae were incubated with another nursery pond by siphoning. The lined females were transferred to a holding tank and continued to be raised until the second time.
1.4.3 Baits of stage I-III baits were mainly composed of single-celled algae, supplemented with soybean milk, and soybean milk was filtered with a 100-mesh sieve and fed 4 times a day. Stage IV to VI were mainly rotifers, supplemented with cooked egg yolks, and the yolks were filtered through 80 mesh sieves and fed 8 times a day. Stage VII juvenile to juvenile shrimp were fed with freshwater and snail meat. The snail meat was filtered through a 40-mesh sieve and fed 10 times a day. The amount of larvae to be fed is slightly surplus.
1.4.4 Water Quality Management Every day at 2:00, 8:00, 14:00, and 20:00, test the water quality with Ante 200 and measure the dissolved oxygen, pH, hydrogen sulfide, ammonia nitrogen, and nitrite in the water. content. During the entire cultivation period, the water quality was adjusted by changing water, air and lime water. The range of water quality indicators was: dissolved oxygen 6-10 mg/L, pH 7.5-8.2, H2S <0.001 mg/L, ammonia nitrogen <0.015 mg/L. Nitrite <0.1mg/L.
1.4.5 Disease prevention When holding the shrimp in the human nursery pool, soak it in 10g/m3 malachite green for 5 min to kill the polypoems and slugworms parasitic on the spawning shrimp. During the nursery period, 1 g/m3 oxytetracycline was sprayed every 2 days to prevent disease.
1.4.6 Inhabitants When 95% of the juveniles reach the stage of IX, some rinsed and disinfected water peanuts and Malay eyelets are placed into the pool to provide a suitable ecological environment for juvenile shrimps.
2 The results used to test the broodstock l500kg, including female 1200kg, about 288,000 tails, the average holding rate was 93%, the average number of eggs is about 3,000/tail.
In 2001, a total of 670 million tailed juveniles were hatched in 450 m3 of nursery water, with a hatching rate of 84%. About 200 million tailed seedlings were grown at lcm, and the average breeding rate was 33%. The highest breeding rate was 41. %. See Table 2 for nursery conditions.
3 Discussion There are many reports on artificial breeding of green shrimp “13,†but mainly indoor small-scale trials and nursery pond ponds. The former stays in the experimental stage and cannot be applied to production. The latter is affected by natural conditions, resulting in low survival rate and yield. Unstable. In this experiment, artificial shrimp brackish artificial nursery facilities of idle crabs are used to breed young shrimp, which can produce large-scale batches of green shrimp prawns with high cultivating rate, tidy larvae, lots of cultivating batches, and high yields. The advantages are of great significance to the development of shrimp culture. At the same time, it has also found a new way for the utilization of idle crab breeding plants in inland provinces.
In the experiment, the larval open bait was combined with biological bait and artificial bait, which not only solved the palatability and nutritional requirements of the larvae, but also reduced the bait cost. After the spawning shrimps are hatched, the spawning shrimps are separated from the larvae by the inverted pool method. Compared with the previous cage row rowing methods, the mortality of the spawning shrimps can be greatly reduced. During the whole nursery period, the death rate of spawning shrimps was only 4.8%, while the death rate from cages was between 16% and 35% “2â€, and the effect of siphoning the pool on the zoea was very small.
It has been observed that although young shrimps are phototaxis, they are afraid of bright light. In the test, the shade cloth was used to cover the stimulation of the larvae by the strong light, and the larvae were fully active in the middle and upper layers of water with rich dissolved oxygen and abundant feed, and the survival rate of the larvae could be improved.