How to raise crabs in rice fields

Rice field crabs are common river crabs. Raising river crabs in rice fields is beneficial to the common growth of rice seedlings and crabs. So how to raise rice field crabs?

1. Growth habits of crabs in rice fields

Rice crabs are crustaceans of the phylum Arthropoda, also known as crabs or hairy crabs. They often live in caves on the muddy banks of rivers, rivers and lakes, feeding on fish, shrimp, animal carcasses and grains.

Rice crabs like to live in caves on muddy banks or tidal flats of rivers and lakes. Under natural conditions, they feed on aquatic plants, humus, animal carcasses, snails, mussels, etc., and occasionally cannibalize each other when there is a lack of food for small fish and shrimps, and even devour their own eggs.

Second, how to raise rice field crabs?

First of all, it is necessary to cultivate buckle crabs, then release buckle crab seedlings, disinfect them before release, and set up anti-escape measures at the same time. When feeding, press 4% of the weight of the crab and feed it 2-3 times a day. In the process of crab culture in rice field, we should also pay attention to dredging and changing water.

Among them, the anti-escape facilities of rice field crabs mostly use plastic film, and some use cement board to prevent escape, depending on their respective conditions.

III. Pest control of crab in rice field

1. Black Gill disease

The gills of diseased crabs are discolored by infection, the left and right Gill filaments appear dark gray or black when light, and all become black when heavy. Diseased crabs move slowly and have difficulty in breathing, commonly known as sighing disease. The disease often occurs in the later stage of adult crab culture. The deterioration of water environment is the main cause of the disease.

2. Rotten shell disease

The tip of the foot of the diseased crab was damaged, turned into a black ulcer and rotted, and then white spots appeared on each segment of the foot and the back armour and chest plate and gradually turned into a black ulcer. In severe cases, the carapace was eroded into a hole, visible muscle or skin membrane, resulting in the death of the river crab. The disease is caused by bacteria caused by damage to the tip of the step of the crab.

Preventive measures:

(1) clear the pond thoroughly with quicklime to keep the water quality clean. Fresh water is often injected in summer to keep the bottom of the pond with 5ml and 10cm of silt.

(2) in the pond with signs of disease, sprinkle the whole pond with quicklime to show 15-20PPM.

Treatment: bleached 2PPM was sprinkled all over the pond, and the swallow was added to the feed with sulfonamides, 0.1 ml 0.2 g per kg feed for 5 days.

3. Water mildew

The flocculent filaments growing on the body surface of the diseased crab, especially in the wound, the movement of the diseased crab is slow, the food intake is reduced, and the wound does not heal, resulting in tissue fester and spread in the wound, resulting in death. the disease is caused by the injury of river crab and mold invading the wound.

Preventive measures:

(1) do not cause crab body injury in the process of cuttage, transportation, stocking and so on.

(2) adding animal feed before molting in large quantities.

Treatment:

The main results are as follows: (1) the malachite green was sprinkled in the whole pool and applied once after 5 days.

(2) wash the diseased crab with 3% salt water for 5 minutes, and smear the affected area with 5% phosphorus.