Management techniques of mixed culture in crayfish ponds

Crayfish, also known as lobster, has strong adaptability, rapid growth, delicious meat, rich nutrition and strong market demand, so it is favored by farmers and consumers. In production practice, crayfish are mainly mixed culture, such as adult fish ponds, fish ponds, river crab, green shrimp culture ponds and so on. Pond mixed culture of crayfish should pay attention to the following problems.

The pond is convenient for entry and drainage, can maintain a water depth of 1 to 1.5 meters, the slope of the pond is better than 1:3, and there are anti-escape facilities around the pond.

It is appropriate to use non-harmful pond cleaning drugs to clear the pond, to completely kill black fish, catfish, water snakes, frogs and other enemy organisms, as well as pathogenic bacteria and parasites.

Keep a certain amount of water plants, branches and other hidden things in the pond for lobster habitat, climbing, shelling and feeding. Some aquatic plants can be planted, such as verticillium verticillata, water peanut, bitter grass, water hyacinth and so on.

Carnivorous fish shall not be cultured in mixed culture ponds, and grass carp and mackerel that feed on aquatic plants should not be too much. The species that can be mixed-cultured are silver carp, bighead carp, allogenic silver crucian carp, river crab, green shrimp and so on.

Can choose to capture wild young shrimp as shrimp species, specifications should be more than 3 cm, sound limbs, strong mobility. It is suitable to put 0.6 ~ 10,000 shrimp species per mu. Shrimp holding eggs can also be selected for breeding in the pond.

The amount of bait should be sufficient, lobsters can kill each other when they are hungry, and they may also eat river crabs, green shrimps and young fish in shelled fish, so bait must be sufficient to meet the feeding needs of lobsters.

The bait should be palatable, and the powdered bait should not be distributed directly into the pond, making it difficult for fish and shrimp to eat, which not only causes a waste of bait, but also pollutes the water quality.

The water quality of the pool should be kept fat, tender and fresh, with a transparency of about 30 cm, a PH value of 7 to 8.5 and a dissolved oxygen of more than 4 mg / L.

Quicklime is used to regulate the water quality and increase the calcium in the water, which is beneficial to the shelling and growth of lobster. In the prosperous growing season, it is applied every 15 to 20 days, and 10 to 15 kilograms of quicklime per mu is used to turn it into mortar and spread all over the pond.

In the prevention and control of diseases and insect pests of fish and shrimp, fish drugs harmful to lobsters shall not be used, especially in the selection of pesticides.

After the shrimp species have been put into operation for 30 to 40 days, adult shrimps with specifications of more than 8 cm can be caught. Net-cage fishing gear such as ground cages are used to do no harm to fish and shrimps. When conditions permit, shrimp species can be restocked according to the conditions of the pond, and rotation catch and release shall be carried out.