How do hotels keep crabs?

The experimental greenhouse is a steel frame double-layer solar panel insulation greenhouse with an area of1.200m2 (20×60) and a water area of1.000m2.. Equipped with aeration facilities and pipeline heating equipment, the light transmittance of the greenhouse is about 50%, and five 200-watt incandescent lamps are installed for night lighting. In order to put the feed conveniently and evenly, three pedestrian walkways are set up.

Preparation before sowing

Before seeding 10 days, put 30 cm of water, and disinfect it strictly with quicklime emulsion 100ppm. After disinfection for 24 hours, start the aeration facility for aeration. Next, put aquatic plants, mainly water peanuts, soak the recovered aquatic plants in high-concentration lime water or potassium permanganate solution for 24 hours, then rinse them with clear water and put them in the greenhouse evenly. The planting area of aquatic plants accounts for about 80% of the water area. Then gradually raise the water temperature to 20 ~ 22℃.

C, stocking crab seedlings

First, put the crab seedling transport box into the water, soak it for about 30 seconds, then take it out of the water, put it into the water for about 5 minutes, then put it into the water for 30 seconds, and repeat this for 4 ~ 5 times before releasing the seedlings. Choose a place where there are no aquatic plants, gently grab a handful of seedlings and shake them slowly, so that the crab seedlings can be evenly dispersed in the water. Although after three hours of transportation, the big-eyed larvae hardly died.

D, daily feeding and management

At the early stage of crab seedlings entering the pond, they were mainly fed with bait such as tofu, fish paste and adults. Filter the tofu into tiny particles with a 40-mesh net, and then spread it evenly in the whole pool with water. After cleaning the small miscellaneous fish, beat them into fish slurry with a beater, add 1% salt to the water and spread them evenly in the whole pond. The daily feeding rate is 100% ~ 150%, and it is fed four times a day, that is, before dawn, at noon, in the evening and at midnight 1 time, in which the lights are turned on at midnight for 2 ~ 3 hours. When the crab seedlings basically grow to the second stage, the bait is mainly bean cake and fish paste, and tofu is occasionally fed 1 ~ 2 times. Bean cakes are still made into small particles after being cooked. At this time, the feeding rate is controlled at about 100%, and the bait is still fed four times a day. During this period, gradually add water to 0.5m.. After stage V, the feeding rate is 60% ~ 80%, and the bait is still mainly bean cake and small fish, three times a day, not at midnight. Observe the activities and food intake of crab seedlings during the whole seedling raising period, estimate the number and weight of crab seedlings in the pond, and determine the reasonable feeding amount. During the period of concentrated molting of crab seedlings, the feeding amount can be appropriately reduced and the light-on time at night can be increased.

The daily management work is mainly to control water quality and disinfect regularly. Sprinkle water with 5ppm lime emulsion evenly in the whole pool every week, supplement some calcium and keep the pH value at 7.5 ~ 8.5; Disinfect with 0.5ppm of 50% stable chlorine dioxide every 10 day/time, and change the water every 1 5 day. The water change amount is about 30%, and some new water should be properly supplemented. The water level should be controlled at about 0.5m. When changing the water, the inlet and outlet should be wrapped with 80-mesh screen wires to avoid discharging seedlings or other harmful organisms. Pay attention to the temperature difference within 5℃, and the water temperature should be basically the same. Pay attention to the growth of aquatic plants in the pond at ordinary times and replenish some fresh aquatic plants in time.