Techniques of hoarding and raising river crabs in winter

River crabs are generally concentrated on the market from the beginning of October to the end of November every year, so the quantity is large and the price is low, and the breeding benefit is not high. Hoarding and raising river crabs in winter is beneficial to stagger the season of centralized listing and increase the listing price of river crabs, so as to obtain the best economic benefits.

1. The pond requires an area of 510 mu, the water level of the pond is maintained above 1.5 meters, the water source is good, it is convenient to enter and discharge, the pond ridge is not leaking, the width of the pond is 2 to 3 meters, and the silt at the bottom is less than 15 centimeters. Ten days before entering the pond, the river crabs were cleared with quicklime and released after 7 days of water injection. Adult crabs are stored in separate ponds before entering the pond.

two。 The quality and quantity require that the river crabs should be disease-free and injury-free, with complete appendages and strong vitality, with an individual size of about 120 grams and 500 to 600 kilograms per mu. Aquatic plants such as water peanuts, verticillium verticillata and an appropriate amount of snails should be put into the pond to keep the river crabs fat less during hoarding.

3. Feed selection according to local conditions, such as melons and fruits, vegetables, bean cakes, aquatic plants, cooked potato strips, wheat grains and chopped small fish and shrimp, silkworm pupa, leftovers from livestock processing plants, etc., animal and plant feed, mainly animal feed, plant feed as a supplement, in which animal feed accounts for 60%-70% of the total feed. When the water temperature is higher than 10 ℃, the daily feeding amount is about 10% of the weight of river crabs. 30%-40% of the full-day dose in the morning, 60%-70% in the afternoon, and when the water temperature is lower than 10 ℃, the feeding amount will be reduced by 3%-5% until hibernation stops feeding.

4. Water quality management river crab likes a fresh water environment with a transparency of about 40 cm, a ph of 7.5 to 8.5 and a dissolved oxygen of 5 mg / L. During the period of hoarding, a certain water level should be maintained, and the depth of the pool should increase gradually with the decrease of air temperature. In order to ensure that the bottom of the pool maintains a high water temperature in cold weather, the water depth should not be less than 1.5 meters. Water should be changed frequently, and 1/3 water should be changed every 7-10 days (large pool) or 3-5 days (small pool) when the water temperature exceeds 10 ℃. When a large area of the water surface freezes, the ice should be broken to increase oxygen. Small ponds should be oxygenated regularly.

5. Patrol the pond to check the water color and water level. Maintain good water quality and sufficient dissolved oxygen; second check the activity, appropriate amount of bait should be given to ensure that they have enough to eat, and the spoiled residual bait should be removed in time to keep the water fresh.