Taiwanese oysters, also known as "oysters", are mainly produced in Changhua, Yunlin and Chiayi in Taiwan.

The oyster meat is fat, tasty and rich in nutrients, and after the fall, the quality is even better, and it is the best aquatic fresh products such as snails and shellfish.

In front of the Longshan Temple in Wanhua City, Taipei, there are a variety of food stalls with various flavors, among which "oyster omelette" often has a unique flavor, beautiful shape and color, which makes people salivate and attracts a lot of diners to come here. Oysters are rich in vitamins and iodine, and their flesh is soft and easy to digest. Chinese medicine believes that oysters can be used to treat dizziness, night sweating, spermatorrhea, leakage, scrofula and other diseases.

(I) Cultivation Methods 1. Raft culture: Choose the sea area with smooth tide, rich bait, calm wind and waves, and water depth above 4 meters for oyster raft culture site. Oysters in the near river should be selected near the estuary with low salinity; oysters in Dalian Bay should be selected far away from the estuary with high salinity; Pacific oysters and pleated oysters are in between. (1) Rope culture: It is suitable for oysters with shells as the fixation base, and there are two ways of cultivation: firstly, the shells with oyster fry are connected into strings with ropes, separated by bamboo tubes of about 10 centimeters in the middle, and then hanged on rafts; secondly, the shells with oyster fry are clamped into the twisted seams of polyethylene ropes with a diameter of 3~3.5 centimeters, and then clamped with one shell every 10 centimeters, and then hung on the floating rafts. Floating raft. General length of each rope 2 ~ 3 meters. You can also use rubber tires to clip seedlings hanging. (2) Net cage culture: use scallop net cage culture. The oyster seedling without fixation base or fixation on the shell oyster seedling together with the shell into the scallop net cage, hanging on the floating rope. Raft culture is generally stocked oyster seedlings for each 667 square meters of 100,000 grains, shells as seedling picker, each 667 square meters can be lifted about 10,000 shells. Oyster seedlings from May and June to start stocking, to the end of the harvest, per 667 square meters of production can reach more than 5,000 kilograms. (1) site selection: beach seeding should be selected wave small, smooth tidal currents, no pollution in the Bay, the substrate to sandy mud beach or mud and sand beach is appropriate. The tide area should be selected in the lower part of the mid-tide area and near the low-tide area. (2) Season of sowing: generally in mid-March to mid-April sowing is more appropriate. Production can be sown in mid-May at the latest. (3) seedling sowing method 1 dry tide seedling sowing: that is, in the ebb tide after the beach surface dry dew seedling sowing. Seedlings should be sown before the beach surface leveling, or built into a bed-shaped base and then sown seedlings. Dry tide seeding should try to grasp the seedling after the start of the tide, in order to shorten the oyster seedling exposed time, to avoid midday sun exposure when sowing seedlings. 2 with water seeding: that is, after the tide by boat seeding. Seedling before the beach into a strip, inserted bamboo poles, wooden poles, etc. as a sign, to be on the boat with a spade after the tide will be oyster seedling sowing. Sowing with water can not directly observe the distribution of oyster seedlings, often resulting in uneven sowing. Seedling density should be sown according to the beach quality good or bad, water fat or thin. Superior mudflats per 667 square meters seedling 12 million or so, medium 100,000 or so, generally poor seedling can be sown 60,000 to 80,000 grains. 3. Oyster, shrimp mixed culture (1) shrimp pond selection: mixed oyster shrimp pond, the substrate to the mud or mud and sand is appropriate, the depth of water for more than 1.3 meters, the average daily rate of water change should be up to about 50%. The transparency should be controlled at 40-50 centimeters in the early stage and 50-60 centimeters in the middle and late stage. (2) Site organization: Before seedling stocking, it is necessary to clear the silt thoroughly and use bulldozers and other tools to level and compact the bottom of the pool where oyster seedlings are played, which is slightly convex and slightly higher than the surrounding bottom surface, so as to prevent oyster seedling from sinking and being buried by silt and dying. (3) seeding: in order to ensure that the normal shrimp stocking density under the premise of oyster seed sowing amount of about 30,000 grains per 667 square meters is appropriate. Sowing time should be selected in early April, seedling seed selector specifications to shell length of 2 cm or more is good. Sowing seedling should be even and avoid the low-lying place of ring ditch and baiting area, and the sowing seedling area accounts for 1/4~1/3 of the bottom area of the pool. 4. Stone casting culture: the stone used as oyster seedling picker becomes the oyster cultivation equipment at this time. Folded oysters with a short growing period can be raised in the seedling collection site in local decentralization; oysters with a longer growing period in the river should be moved to the cultivation site for cultivation. There are mainly three kinds of cultivation methods: (1) Starry sky: oyster stones are placed in an unorganized manner. (2) plum blossom type: generally 5 to 6 oyster stones as a group. (3) rows and columns: row width 0.5 ~ 1 meter, row spacing of 0.6 ~ 1.5 meters. Deep-water aquaculture can be in the stone picking seedlings without any management until the harvest. 5. Bamboo culture: the use of bamboo seedling picking method, the oyster seedling will be picked up on-site sparse culture. Raised, oyster bamboo arrangement of two ways: (1) straight: 150 ~ 179 oyster bamboo straight into a row, row length of 3 to 5 meters; or 100 ~ 120 oyster bamboo into a row, rows of the middle of the rows to leave 2 to 3 gaps, in order to open up the flow of water. (2) oblique insertion: 23 to 26 oyster bamboo inserted into a heap, the bottom of the heap width of 45 to 60 centimeters, the top of the width of 33 to 36 centimeters, the heap and the heap between the distance of 20 to 25 centimeters. From 5 to 6 piles to form a row, row to row about 2.5 meters apart. Each 667 square meters can be inserted 8000 ~ 10,000 oyster bamboo. 6. Bridge type culture: the use of bridge type seedling picking method of seedling picking, will be rearranged, evacuation of the density of the stone bar, to raise. General 6 ~ 7 stone for a group, group and group with stone connected to a column. The distance between groups is 50-60 cm, and the distance between columns is 1-2 meters. During the period of cultivation, the negative side and the positive side of the stone bars should be exchanged so that the oysters on both sides can grow evenly. 7. Standing stone cultivation: After picking seedlings in the mid-tide area using standing stone seedling picking method, as long as the quantity of seedlings is suitable, the oysters can be left to grow naturally without any management until harvesting. This method is mainly used in the cultivation of pleated oysters. 8. Grid culture: This culture method is to set up a fixed grid in the inner bay after the water depth is 2-4 meters, wind and waves are calm, and the bait is here, and the setup of the shelf is the same as that of the grid type of seedling harvesting. Oyster seedling mostly in series of shells, cement tiles and other solid base, hanging in bunches on the fence frame raising. Each string length 1 ~ 1.5 meters, string spacing 0.5 ~ 1 meter. Breeding density should not be too high, strictly prevent the bottom, so as to avoid the invasion of some benthic hostile organisms. (ii) Management during the period of cultivation 1. Turning over the stone (shifting stone): it is to move the position of oyster stone. Turning over the stone can prevent oysters from being suffocated by silt, and can stir up the floating mud, increase the nutrient salts of the bait, and promote the growth of oysters. Generally, the oyster rocks are turned over 2 to 3 times during the period of cultivation. 2. Flood prevention: In the rainy season, it is necessary to pay attention to preventing the inflow of flood water, or digging a ditch around the dike to fight against flooding, or moving the oysters to the high salt deep-water sea area for temporary cultivation. 3. Overwintering: Dalian Bay oysters and oysters cultivated in the northern part of the country generally have to go through 2 to 3 winter freezing periods. It is necessary to check the oysters once before freezing and transplant the oysters which may be threatened to the deep water so that they will be safe for wintering. 4. Fertilization: 1~2 months before harvesting, oysters should be moved to good fertilization farms for the purpose of increasing production. 5. Preventing man-made trampling: beach oysters can only filter water on the beach surface for feeding, and once they fall into the mud, they can't live normally and suffocate to death. It should be forbidden to trample on the beach at will, and the managers should march along the ditch when they go down to the beach. 6. Dredging ditches: check whether the drainage ditches are smooth or not, and try not to accumulate water on the beach surface after the tide goes out, so as to prevent oyster death caused by high water temperature, enemy submergence and deep mud floating. 7. Pest removal: there are many enemy pests of oyster, which should be removed when combining with turning over stones. During the breeding season of red snail and lychee snail from July to September, they should be caught by diving to catch their parental shells and egg sacks. In the season of frequent crab activities, strengthen the management and capture the enemy. 8. Windproof: typhoon is very destructive to aquaculture facilities, and it also rolls up mud and sand to bury the fixer and oyster. Therefore, after the typhoon, it is necessary to salvage, repair the rafts and plant the fallen or buried fixers. (III) Prevention and control of common diseases 1. Bacterial ulcer disease of larvae: The pathogens are Vibrio anguilla-rum and Vibrio alginolyticus, etc. In the nursery process of various oysters, it is necessary to repair the rafts and support the fallen or buried fixers. The disease may occur in the nursery of various oysters. When the floating larvae are infected, they will sink and solidify, or their activity ability will be reduced, and they will die suddenly in large numbers. Prevention and control methods: 1) keep the water quality clean: 2) find the diseased larvae immediately discarded; 3) feed the single-celled algae without vibrio contamination; 4) individually or jointly with the use of filtration, ozone and ultraviolet disinfection of broodstock water; 5) per cubic meter of water body with the composite streptomycin 50-100 grams or chloramphenicol 10 grams of the whole pool splashing, for 3 to 5 days. 2. Perkins disease of oyster: the pathogen is seawater Perkinsus ma-rinus. Perkins disease is one of the most serious diseases of oyster. It has a wide geographical distribution. It mainly affects oysters older than one year. Oyster mortality occurs in the summer and early fall (August-September) and decreases thereafter as the weather gets colder and water temperatures drop. Epidemics are associated with higher water temperatures (30°C) and higher salinity (30×10?3). Oysters do not die when salinity is below 15 x 10?3 or when water temperatures are below 20°C or above 33°C, even if they are parasitized by Paecilomyces. In chronically infected oysters, the body gradually wastes away, growth stops, and the development of the reproductive glands is impeded. Seriously infected oysters die with their shells and mouths open, especially when the environmental conditions are unfavorable. Prevention and control methods: 1) avoid using infected oysters as fry; 2) before the oyster larvae fixation and metamorphosis, clean the fixation thoroughly, remove the old oysters completely, remove any objects between the oyster beds to which live oysters are attached, and don't let the oyster beds be too crowded; 3) harvest oysters as early as possible when they reach the proper size to avoid the occurrence of the disease; 4) oysters can be raised in the sea with low salinity (?15×10?3) to suppress the development of the disease. disease development.

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