The purse seine from the Lake Yangcheng Lake in Bacheng, Kunshan, began in 1987. At that time, it was only nearly 1,000 acres. In 2000, it was developed to 25,000 acres. This article makes a summary of the technical points of raising crabs on lakes and purses of Yangcheng Lake in Bacheng. First, aquaculture water selection Second, the fence material preparation 1. Mesh uses 12 shares of 8 to 9 mesh. 2. The column pile uses 20-25 cm bamboo, the bar should be straight, even without damage. 3. The bottom gabion is made of 246 stones. 4. Other accessories Moso bamboo, plastic lines, ropes, lead wire and so on. Third, the fence area Generally 30 to 50 acres is good, the shape of a square or rectangular. Fourth, fence setting 1. Generally, at the end of the year or January of the following year, according to the requirements, choose a flat, deep trench-free water area to be piled, and the pile spacing is 1 meter. Build a fence fence and reinforce it to prevent the strong wind from falling. 2. The height of the fence is high at the water level 80 to 100 centimeters above the flood season. It must not be too low to prevent the flood season from flooding. 3. Set up a counter-netting net at the end of the fence to prevent it from fleeing. The width is 50 cm, and it is inclined inwards and downwards with an angle of 45 degrees. When setting, pay attention to the connection between the net clothing and the bamboo piles to be a bit looser and not too tight. Otherwise, it is easy to be damaged by the wind. 4. The gabion setting (1) The diameter of the main gabion is preferably 10 to 12 centimeters. The filling stones cannot be full and they are good at 70% to 80%, so that they can be easily laid and attached. (2) The diameter of the auxiliary gabion is 5 to 6 cm and it is laid on the inside of the main gabion at a distance of 50 cm to prevent the crabs from fleeing due to damage to the main gabion. 5. After all the fences are set up, a cage net should be set up on the four sides of the fence. Through routine inspections, it is timely to know if there is any crab escape. V. Breeding management 1. Crab species stocking (1) Stocking time: From March to March, stocking was conducted, and healthy and disease-free wounds were selected. The size of the Yangtze River water crab was 60 to 80/kg. At this stage, the water temperature is relatively low, and crab species are not strong enough to escape and damage. At the same time, early stocking, early adaptation, and early growth can be achieved. (2) Stocking Density: According to the natural food in the aquaculture waters, generally about 400 animals are stocked per acre. (3) Sterilization of crabs: Dissolve 2 to 3 times of potassium permanganate 10 to 15 mg/L before releasing seeds, each time for 1 to 2 minutes until the crabs spit water with red color. Through drug soaking, both insecticidal and bactericidal, while effectively improving the survival rate of culture. 2. Supplemental natural bait is generally added in the early April of the planting season. In the breeding fence, fresh snails are added, 300 to 500 kg per mu. One is to let snails reproduce naturally and increase the total amount of natural food. The second is to remove the food scraps left by the crabs in the seine nets and achieve the purpose of purifying the sediments. 3. Artificial bait feeding lakes to raise crabs to the main natural bait, supplemented by manual feed. (1) In general, after April, as the water temperature rises, the food intake of the crab increases. According to the natural food conditions in the fence, some fresh wild fish or chilled fish are properly fed and sprinkled in the shoal of the seine. Can be fed some cooked corn, wheat and so on. (2) In June-August, add some non-polluting drugs regularly to make baits to prevent and treat crab disease. (3) The amount of bait should be controlled within 2 hours. It is advisable to finish it within the 2 hours. Do not overdo it. Otherwise, it is easy to spoil the sediment and induce crab disease. 4. Daily management (1) Focus on seine management. Check every day, mainly to see if there is any escape of crab inside the cage net around the perimeter of the fence, and determine the escape position and take timely measures. 3 days a small investigation, mainly to check the fence solid and damaged. In the seven-day inspection, it is mainly checked whether the gabion is attached or lifted. (2) Inspect once every morning and evening. One is to remove debris from the seine nets; the other is to check the growth and abundance of aquatic plants and formulate corresponding measures; and the third is to check the feeding activities of crabs and determine the feed amount of bait. Six, fishing After several months of cultivation, the crabs basically enter the mature stage at the end of September and can be harvested and listed. Fishing methods: 1 The cage nets are used in the fences and nets, and the large-sized knotted nets are better, setting 2 to 3 per mu. Article. 2 It can also be arrested on the anti-escape and anti-cowl. The general recovery rate is about 70%, and the specification is about 150 grams. VII. Benefit Analysis Commodity crab 40 kg, 210 yuan per kilogram of unit price, total income 8400 yuan. The cost is 2530 yuan, of which the seine net investment is about 1,000 yuan per mu, divided into three years, 330 yuan per year; the cost of crab species is 400 yuan, the artificial bait is generally about 600 yuan, the rent is 200 yuan, the labor cost is 800 yuan, and others The cost is 200 yuan. Benefit 5870 yuan. Rushan Jinguo Food Co., Ltd , https://www.jinguofood.cn
Choose freshwater lakes with clear water, slow running water, and water depths of about 1.5 meters. The bottom material is preferably hard-bottomed, flat at the end, free from deep trenches, and the mud is good at about 10 cm. Lakes have rich natural aquatic resources and more benthos.