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The long oyster, also known as Pacific oyster, is called true oyster in Japan and is a broad-salt, wide temperature oyster variety. Because it has the characteristics of delicious taste, large individual, fast growth, strong adaptability, and high yield, it is one of the fine varieties of oyster culture in the world. Lianjiang County introduced oyster seedlings from Japan in 1982. Since the 1990s, with the continuous improvement of aquaculture technology, good economic benefits have been achieved. At present, the long oyster breeding has grown to nearly 20,000 mu, forming shallow sea development. A large industry, while the level of artificial breeding technology continues to improve, the technology gradually improved, in addition to the production of seedlings in addition to the county breeding also sold to Guangdong, Zhejiang and other places. The author of this article through a few years of practice of artificial breeding of long oysters, the initial control of the seedling technology, now summarizes the technical points in the nursery process are as follows: 1, the fertilized egg obtained 1.1 dry, water production: select the natural sea or sea water The mature ponds of the gonads were raised in the pond and dried in the nursery pool after being dried and disinfected. The method of flowing water is direct water flow through the water inlet valve or impact with a water pump, etc. The mature progenitors of the gonads can emit sperm and eggs after being stimulated by flowing water for 1 hour. Observe carefully during spawning process and remove male body in time to avoid affecting water quality by extra semen. At the end of spawning, the pro-Bégé fresh seawater was picked up to incubate him under micro-aeration conditions. The hatching density of fertilized eggs was controlled at about 10/ml. The above-mentioned dry and flowing water production methods can achieve good oxytocin production as long as the parental gonads are mature enough. 1.2 Gonadal anatomy: The pro-beads were cut open, and the sperm and eggs were artificially inseminated in the container. The sex ratio was 10-15:1 for the number of pro- and baits. After fertilization, it is necessary to use clean seawater after several times of egg washing before hatching. The hatching method and points are as above. Since the operation is relatively inconvenient, this method is used when the maturation of pro-folliculitis is not good or irregular in production. 2. Development of Planktonic Larvae Fertilized Eggs After development into D-type larvae in hatchery ponds, the superior larvae of D-type larvae in the hatching pool are incubated in the cultivation ponds. The density of larvae is 4-5 pieces/ml. The larvae are larvae throughout the planktonic larvae. Growth and survival conditions often use methods that continue to be diluted in the pool 2-3 times. First use the water method, after the pool began to change the water, 1/4-3/5. During the breeding period, the bait is best used as a mixture of various species. Commonly used algae include micro-algae, P. hornata, C. renifolia, and Platymonas palustris. The amount of feeding varies depending on the cultivation water temperature, water exchange volume, and larval density. , feeding conditions, pool water turbidity, seedling pool light intensity and other circumstances. The planktonic larvae should be cast less in the early period and more in the later period; the young larvae should be less in density when the larvae are small, and the big ones can be cast in more; the pool water should be less turbid, and the clear can be cast more; the light should be less when the flukes are below 500 Lux. In the 1000-2000Lux can be multi-cast; castanopsis micro algae, flat algae should be less vote (digestion slightly worse), Phoenix algae, chaetoceros as the bait can be more vote; small amount of water should be less investment, large Can cast more. The use of different algae is better supplemented by gold algae and chaetoceros, with the aid of micro algae and Platyclad bait for raising seedlings. For example, at the Guanwu nursery in Lianjiang County in early July 1999, there was a group of Pacific oyster nursery at the water temperature. At 27-28°C, seawater specific gravity 1.020, larval density 3-1/ml, light 1000-2000Lux, the daily rate is 2-30000/ml, the larvae grow fast and develop from the D-type larvae. Individual eye spots only need 11d, on the thirteenth day can be attached to the seedlings, seedlings with good results. Sometimes in the breeding process, due to unexpected accidents in the cultivation of biological feed, it is not possible to mix and use different types of micro-algae alone. Although they can continue to grow and develop, they often show slow growth and prolong the appearance of eye spots. The effect is also affected. 3, juvenile breeding When the larvae appear more than 505 when the eye point can be injected into the bleaching powder disinfection clean long oyster clam shell with a seedling device, in order to make the larvae even after shelling to increase the amount of inflatable, daily water change twice , The amount of water changed from 2/3 increased by 3/4. After the larvae were abnormally attached, the food intake increased significantly, and the feeding amount should be increased. The daily feeding was increased from two times to three times. The micro-algae of Yunnan, Yunnan Dalyphai were used as bait series, and the daily amount of microalgae was 80,100,000-1000ml/ml. , Qingdao large screen algae 0.4-0.6 million / ml. After the larvae are attached, the secondary shells are metamorphosis to juveniles after 3-5 days, and then they can be raised in the sea for a short period of time after 2-3 days cultivation. Before the juveniles go out of the pool and dismiss the sea, they are forced to abandon the seedlings in the nursery pool for 2 days. This will allow the juveniles to attach more firmly and improve the survival rate of the juveniles. 4, the treatment with a seedling device is currently used for the long oyster shell with a seedling device, due to oyster shell attached with more barnacle and other attachments, be sure to clean, wash thoroughly, conditional shells on the beach Let the waves scouring for a few days, the effect is better, and then use bleaching powder disinfection, rinse can be used before, or after the release of seedlings attached to the plant due to attachments corruption and decomposition of ammonia in the pool water increased, the water quality is corrupted, affecting the larvae attachment rate. 5. Disease and Pest Control As the area of ​​shallow sea aquaculture continues to expand, the pollution of aquaculture itself is becoming more and more serious, the pests and diseases of breeding organisms continue to occur, and the pests and diseases in the artificial breeding of long oysters are also quite prominent. In places with poor water quality, the use of bleaching powder and reduction with sodium sulphate will not solve the problem of the larvae's sinking. If the water quality is slightly better, the larvae face discs caused by Vibrio, etc The cilia have stuck in the watershed, and there are symptoms such as parasitism in the body causing the larvae to sink, resulting in low survival rate of the artificial seedlings, especially the post-larvae metamorphosis attachment rate is very low, and the attached larvae easily fall off and die. The author believes that from the point of view of microbiological changes, when a certain species of aquaculture develops to a certain scale, the natural sea area often produces and corresponding pathogenic bacteria, so the Pacific oyster nursery is best built in a place far away from the breeding area of ​​the species. The nursery, which has been established near the Pacific oyster culture area, not only treats the water quality, but also satisfies the ecological conditions required for larvae and juveniles, and appropriately uses a broad-spectrum, high-efficiency, and low-toxicity antibiotic to treat water before the occurrence of the disease. Prevention, and sometimes have a certain effect, but the amount of drugs, the number of times shall not exceed two times, otherwise it will cause damage to the larvae's organs, causing the larvae to sink and die. For parasites attached to the surface of larvae, copper sulfate and trichlorfon have certain control effects, but there is no good medicine for parasites in the body.