How Do Crabs Overwinter? Key Points of Overwintering Management Techniques for Farming

The vast majority of crab species live in the sea or coastal waters, while some inhabit freshwater or land, and the number currently farmed artificially is also relatively large. So, how do farmed crabs overwinter?

1. How do farmed crabs overwinter?

Clean up the silt in the pond in time and do a good job of disinfection management. Check the pond for leaks and take blocking measures to prevent the invasion of natural enemies and, even more, to avoid escapes. Feed mainly animal-based feed, with plant-based feed as a supplement, of which animal-based feed accounts for 60-70% of the total feed. Patrol 1-2 times a day and pay attention to their foraging situation. When the water temperature is below 10 degrees C, reduce the feeding amount by 3-5% until feeding stops during hibernation.

2. Crab farming techniques

1. Build the farm

A suitable crab farming site should have good water quality, sufficient water sources and convenient drainage. To ensure good air permeability, sandy land or sandy loam should be the main type. The water depth in the pond should be controlled at about 1 m, and the shallowest place must not be lower than 10 cm. In the completed pond, leave several earth mounds and plant aquatic plants such as reeds, wild rice stem and cattail. On the one hand, these aquatic plants are a good source of nutrients for crabs to eat. On the other hand, they help consolidate the embankment and avoid water leakage caused by burrowing.

2. Variety selection

Variety is the key to achieving high yield. At present, most are mainly Yangtze River mitten crab seedlings. At the same time, ensure they are robust, uniform in size and have good adaptability. After selecting good crab seedlings, first soak them in the pond for a few minutes, repeat this several times, and observe the crabs' adaptability to water quality; when there are no adverse reactions, they can be put in. At present, mixed farming of crab seedlings with other fish species is the main approach; on the one hand it provides a food source for the crabs, and on the other hand it can improve the economic benefits of farming.

3. Feed

Ensure the food is fresh, mainly provide meat-based feed, and appropriately pair it with some nutritious vegetarian food, especially using more plant-based feed, so as to ensure good water quality in the pond. The number of feedings should be determined according to changes in climate and temperature. In hot summer, feeding 1-2 times is enough. The specific amount depends on the body weight of the river crabs. If there is leftover residue, it should be salvaged and cleaned up immediately to avoid spoilage affecting water quality.

4. Prevent escapes and natural enemies

Carry out daily patrol work well. Patrol at least 1-2 times a day, once in the morning and once in the evening, and pay attention to the foraging situation of the river crabs. When abnormal situations occur, immediately check whether disease is present, so as to actively use the right medicine and avoid the spread of infectious diseases affecting farming benefits. As the farming quantity increases, water hypoxia occurs from time to time, so water replacement and oxygenation should be done in time to reduce the high mortality caused by hypoxia. In addition, check the pond for leaks and take blocking measures to prevent the invasion of natural enemies and, even more, to avoid escapes.

5. Disinfection management

Remove pathogens and bacteria in the pond to create a good farming environment for healthy river crab farming. Before and after farming, disinfection management of the pond should be done well. Before juvenile crabs enter the pond, disinfection should be done in advance and the silt in the pond should be cleaned up in time.

Crabs also hibernate in winter, so doing a good job of daily patrol work is very important.