Detailed Explanation of Key Points for Freshwater Prawn Seedling Breeding Technology

Among prawns, the freshwater prawn is relatively well-liked by everyone, because the flesh of the freshwater prawn is more delicious, and the living environment of the freshwater prawn is relatively clean, so the freshwater prawn is also easier to clean when eaten, therefore the market demand for freshwater prawn is greater.

Pond culture conditions for freshwater prawn seedlings  

Self-propagated freshwater prawn seedlings generally can produce 3 million to 4 million seedlings of about 2 cm per mu. Farmers can determine the area according to demand and select several ponds of 1-3 mu. The pond sludge is required to be below 15 cm, the pond depth 1.5 m, the pond water supply and drainage system complete, the water source conditions relatively good, and the water quality free of pollution.

Preparatory work for freshwater prawn seedling culture  

1. Thorough pond clearing. The breeding work is generally carried out at the end of May, so the pond should be disinfected at the end of April and the beginning of May. Drain the pond water to 10-20 cm, and use quicklime to clear the pond with water, with a dosage of 150-200 kg per mu, requiring even sprinkling.  

2. Planting aquatic plants. Begin transplanting aquatic plants 7-10 days after pond clearing, with Hydrilla verticillata being the best. This grass is easy to survive, grows relatively fast, and forms creeping stems that facilitate resting for the hatched juvenile prawns. To enable the aquatic plants to form a community relatively quickly, a small amount of organic fertilizer can be applied. After the aquatic plants have formed a community, egg-bearing prawns can be stocked.  

3. Disinfection and pest elimination before stocking. Before stocking egg-bearing prawns, pest elimination treatment should be carried out according to the conditions in the pond. Apply insecticidal drugs such as Yuchong Shaxing, which are less irritating to prawns, 4-5 days before stocking to kill large cladocerans, water spiders and other aquatic insects in the water, and at the same time raise the pond water to 50-60 cm.  

Stocking egg-bearing prawns for freshwater prawn seedlings

After the drug effect in the pond water has disappeared, stock egg-bearing prawns at 8-10 kg per mu, requiring the selection of egg-bearing prawns with relatively good germplasm from open waters or lakes. To facilitate observation of the development of fertilized eggs, 3-4 cages of 1-2 sq m can be set up in one corner of the pond, with about 50 egg-bearing prawns stocked in each cage, and the color changes of the fertilized eggs observed every day. When the fertilized eggs turn purple and eye spots appear, decomposed organic fertilizer should be piled and applied at the four corners of the pond, preferably chicken, duck or cow manure, to cultivate suitable palatable feed in the pond so that the newly hatched nauplius larvae can obtain first feed.  

During the period when egg-bearing prawns are in the pond, 1-2 kg of chopped small trash fish should be fed every day.  

Daily management of freshwater prawn seedlings

1. Feeding. After the fertilized eggs of the egg-bearing prawns hatch, feed soybean milk into the pond. Initially, feed 1 kg of soybean-ground soybean milk per mu per day, and adjust as appropriate according to the pond water color and weather.  

2. Management. During the juvenile prawn cultivation period, apply probiotics such as EM original liquid and photosynthetic bacteria once a week to improve water quality and supplement suitable palatable feed. Apply quicklime once every 10 days to regulate water quality and supplement calcium sources, with a dosage of 15 kg per mu at 1 m water depth, so that the pond water pH value is between 7-8.  

3. Monitor water quality every day. Measure dissolved oxygen, pH value, ammonia nitrogen, nitrite, etc. daily, and handle according to the measurement results.  

4. Add new water in a timely manner. When carrying out freshwater prawn breeding, the water inlet and drainage must be strictly controlled. The water inlet and drainage outlets must be filtered with 60-mesh silk gauze to prevent wild trash fish or fish eggs and other aquatic animals from flowing into the pond. During the seedling cultivation period, add new water once every 4-5 days, with a water addition amount of 10-15 cm.  

5. When the seedlings grow to about 1 cm, artificially compounded powder feed can be used instead, with main ingredients such as wheat bran, fish meal, wheat middlings, etc. During the cultivation period, pay attention to the growth of aquatic plants in the pond. If too dense, they should be removed to avoid competing for nutrients.  

Capture and transportation of freshwater prawn seedlings

Generally, after 30-40 days of cultivation from the stocking of egg-bearing prawns, the juvenile prawns can grow to about 2 cm, and at this time they can be considered as seedlings for commercial prawn culture. A summer fry net can be used for seine netting. Before capture, the aquatic plants in the pond should be removed to facilitate seining operations. For short-distance transportation, live fish buckets with oxygen can be used. Depending on the transportation distance, each bucket can hold 300,000-400,000 tails within 2 hours. During transportation, some aquatic plants can be appropriately laid in the container, which can improve the survival rate of transportation.

In the process of culturing prawns, daily management of them is very important. Prawns also like to live in watery environments, so farmers must also pay considerable attention to their water quality and living environment. Only by improving their living environment can the prawns survive better and improve their quality of life.