How to raise river crabs? What are the key points of daily management?

River crab is also called "crab" and "hairy crab". The head breastplate formed by the combination of head and chest is square and round and hard. River crab is a variable temperature crustacean, and its suitable water temperature for growth is 15-25 ℃. Doing a good job in the culture and management of river crab during the growing period can improve the quality and yield of river crab and increase the income of farmers. How to raise river crabs? What are the key points of daily management?

First, how to raise river crabs?

There are many ways to raise river crabs. Take the lake net as an example:

⒈ girth construction

The double-layer net is adopted, and the distance between the two layers is 5m. Phyllostachys pubescens (trees) are used as fixed piles around the net, each pile spacing is 2mur3m. After the cut polyethylene mesh is sewn, it is tied to the pile with a rope, which is pulled up and down into a plane, and the bottom of the net is fixed with a stone cage and ground anchor, so that the foot of the net is fastened to the bottom mud. The stone cage is pressed into the sediment 20cm, the upper part of the net is 1.5m higher than the water, and the top is equipped with a "T" type net. The upper side of the net is provided with a net eaves made of plastic film vertically downward from 30-50cm, and affixed to the net.

⒉ recommended snail throwing

After the net enclosure facility was built, electric traps were used to catch the large ferocious fish in the culture area. From February to March, Elorella was planted. 2-3kg per m2 of grass stem was used to evenly step into the mud at the bottom of the lake. It could take root and grow in about one month, and several water plants such as Artemisia grass and Reed were transplanted at the same time, and the water peanut community with a total area of 1 million was transplanted on the water surface. Put fresh snails into the net before the Qingming Festival, 500kg per mu. Create a good ecological environment and provide high quality natural bait for crab fish.

⒊ seedling stocking

The breeding of crabs should be carried out one month after the recommended snail, or you can put the crabs around a small piece in advance. Captive fish species are released from May to June. Disinfect the crab species with potassium permanganate or salt, fish seed with bleach or trichlorfon for 10 minutes and 30 minutes. Select the authentic high-quality "buckle crab" of the Yangtze River system, which requires the same specification, about 160fish / kg, and the stocking quantity per mu is less than 600. at the same time, it can store 6-9cm mandarin fish and 2-3cm Pelteobagrus fulvidraco larvae, which are about 20 and 50 per mu respectively.

⒋ feed feeding

Regularly supplement aquatic plants and snails to make crabs feed mainly on natural bait. In the early stage, in order to make snails reproduce and grow, some fresh snail clam meat and small mixed fish can be properly fed. In the later stage, the bait made of pumpkin, shredded potatoes, fresh fish, fish meal, bean cake and soybeans were fed once a day to supplement the nutritional deficiency of natural bait and ensure the fat and fat of crabs. The feed should be fresh, palatable, non-mildew, rotten and deteriorate, and the leftover bait should be fished out in time so as not to spoil the water quality.

II. Key points of daily management of river crab culture

The quality of daily management directly affects the economic benefits of river crab culture. The following points should be done in management:

1. Regular inspection and reinforcement of escape prevention facilities, especially in rainy seasons and windy and rainy seasons, should be strengthened to prevent escape facilities from being blown down by strong winds, pool ridges damaged by heavy rain and flooding the pool, so as to prevent river crabs from escaping.

2. Insist on inspecting Tangkou sooner or later. In the morning, the main thing is to check whether there is residual bait in the pond, in order to arrange the amount of bait for that day, clean the food field, remove the residual bait, create a clean feeding environment, and observe the water quality of the pond at the same time. Decide whether the water needs to be changed or improved. The main purpose of the evening inspection is to observe the activities, eating and growth of river crabs, and to adjust the feeding and management measures in time when problems are found.

3. Regularly check whether there is leakage in the ridge of the pond, whether the anti-escape net of the inlet and outlet is intact, ensure that the water level of the pond is stable, and prevent the river crab from escaping from the leakage place and the outlet, especially the newly dug crab pond, pay more attention to prevent the escape crab.

4. Maintain the quiet environment of the pond. River crab requires a quiet environment, man-made shock, enemy attacks will often cause the river crab to die in the process of molting. Therefore, in the process of raising crabs in the pond, the environment of the crab pond must be kept quiet and do not interfere with the feeding and molting process of river crabs too much. Especially during the period of a large number of molting of river crabs, the action of feeding and cleaning the food field should be lighter in order to improve the survival rate of molting.

5. Strengthen the prevention and control of enemy damage, find rats and snakes, catch them with forks in time, and kill rats with bait in time.

6. it is necessary to do a good job in preventing theft. In autumn, sexually mature adult crabs come ashore in large numbers. Especially at night, crabs come ashore and crawl along the anti-escape board, which is very easy to catch. Therefore, special personnel should be arranged to be on duty all night in order to avoid man-made losses.