Experience sharing on mixed culture of river crab and bass in ponds

1 Pond clearing and preparation

After the pond is exposed to the sun, use 80kg of quicklime per 1/15 hectare to clear the pond and disinfect it, killing harmful organisms and pathogenic bacteria. 7d before stocking crab seedlings, fill with water to about 0.5m, apply 60kg of chicken manure per 1/15 hectare, cultivate plankton feed, and make the water color yellow-green, with transparency 30cm. Also plant some aquatic plants to provide habitat for river crabs.

2 Seedling stocking

2.1 In mid-May, stock 1000 juvenile crabs per 1/15 hectare, with a size of 160-200 per unit. Crab seedlings are required to be robust, with complete limbs, no parasites, and no diseases.

2.2 In late June, stock 30 desalinated bass fry per 1/15 hectare, with a size of 2.5-3cm. Bass fry are required to be uniform in size, agile in movement, normal in body color, and free of parasites and other diseases.

2.3 Stocking precautions Bass are relatively fierce by nature. In fish-crab mixed culture, attention should be paid to controlling the time difference in seedling release. Wait until the crab seedlings grow to about 60-80 per unit before putting the bass fry into the pond, which can avoid juvenile crabs being harmed. At the same time, large-size crab seedlings should be stocked as much as possible.

3 Feeding management

3.1 Feed feeding River crab feeding adheres to the principle of “mixing meat and vegetables, combining green feed and concentrated feed.” Before the bass fry are put into the pond, feed juvenile crabs mainly with animal-based bait to make the juvenile crabs grow to 60-80 per unit as quickly as possible. Throughout the entire breeding process, the feeding proportion of complete formula feed for river crabs accounts for about 30% of the feeding amount. The feeding amount should be flexibly controlled according to the growth, feeding, and weather conditions of the river crabs. Regularly add molting hormone to the bait to prevent incomplete molting. Bass are fed complete fish pellet feed, adhering to the four-fixed principle.

3.2 Water quality regulation River crabs like a fresh water quality environment, and the transparency should be controlled at 35cm. In the high-temperature season, add 10cm of water every day until the highest water level is reached, and splash EM biological preparation over the whole pond 1-2 times to improve the water environment.

3.3 Disease control Each month, appropriately splash quicklime and monocalcium phosphate to improve water quality. The dosage per 1/15 hectare is 10kg. Bass are carnivorous fish. Fish-crab polyculture can eat excess small miscellaneous fish and shrimp. This keeps the water quality fresh and greatly reduces the occurrence of diseases.

3.4 Pond patrol Observe the water color, escape prevention, feeding, and molting conditions every day. So that countermeasures can be taken at any time.