A Detailed Guide to Crayfish Farming Techniques and Management Key Points

In the process of farming crayfish, mastering certain farming techniques is very important. We all know that for many beginners, they are actually only attracted by the development prospects of crayfish, but they have not studied in depth the efforts required in this farming.

Crayfish Farming Techniques

I. Farming Facilities

The pond area should preferably be 4 to 10 mu, with a depth of 1 to 1.5 m and a slope ratio of 1:2.5. The pond bottom should be flat, and the substrate is best if it is loam; the pond slope soil should be relatively hard, the pond should have good water retention, and the water level should be easy to regulate. The water source should be sufficient and the water quality pollution-free. Following the layout of high irrigation and low drainage, build the inlet and drainage channels well so that water can be let in and drained out. Procambarus clarkii has a strong ability to escape, so escape-prevention facilities must be properly built. Usually plastic film or calcium-plastic boards are used, supported around the pond ridge with bamboo stakes or wooden stakes to enclose and prevent escape.

II. Preparation Before Stocking

1. Thoroughly clear and disinfect the pond. 20 to 30 days before stocking shrimp fry and shrimp seed, drain the pond water, remove excess silt, repair the pond ridge, and use 75 kg of quicklime per mu or drugs such as bleaching powder or bleaching powder concentrate to thoroughly clear and disinfect the pond.

2. Apply sufficient base fertilizer. Apply 500 to 600 kg of decomposed livestock and poultry manure per mu to cultivate rotifers and cladoceran and copepod plankton, providing suitable food for the shrimp fry and shrimp seed.

3. Plant aquatic plants well. Plant aquatic plants such as Hydrilla verticillata, Potamogeton malaianus, and Elodea in the pond, covering 2/3 of the shrimp pond area. At the same time, set up netting, or place bamboo tubes, plastic tubes, etc., to provide Procambarus clarkii with habitat, molting, and hiding places.

Stocking Models for Shrimp Fry and Shrimp Seed

I. Farming models. Multiple farming models can be adopted.

1. Summer stocking model. Mainly stock the first batch of juvenile shrimp hatched that year, with stocking time in mid-to-late July, and juvenile shrimp size above 0.8 cm. Stock 30,000 to 40,000 tails per mu.

2. Autumn stocking model. Mainly stock large-size shrimp fry or shrimp seed cultivated that year, with stocking time from mid-August to September. For shrimp fry about 1.2 cm in size, stock 25,000 to 30,000 tails per mu; for shrimp seed 2.5 to 3 cm in size, stock 15,000 to 20,000 tails per mu. A small portion can reach market size by the end of the year, while most must be harvested and marketed from June to July of the following year; commercial shrimp weigh 25 g each, with a yield of 300 to 500 kg per mu.

3. Winter-spring stocking model. Generally stock in December or from March to April of the following year. Mainly stock shrimp that did not meet market size that year, with a size of 100 to 200 shrimp per kg, and stock 15,000 to 20,000 tails per mu. After winter-spring farming, harvest and market from June to July, when commercial shrimp can weigh up to 30 g each, with a yield of 400 to 500 kg per mu.

II. Seedling quality. The quality requirements for shrimp fry and shrimp seed are:

1. Uniform size. Juvenile shrimp size above 0.8 cm, shrimp seed size about 3 cm. The shrimp fry and shrimp seed stocked in the same pond must be uniform in size and stocked in sufficient quantity at one time.

2. Strong physique, complete appendages, no disease or injury, and strong vitality.

3. Shrimp fry and shrimp seed are all artificially cultivated. If they are wild shrimp seed, they should be domesticated for a period before stocking to avoid fighting and killing each other.

III. Notes:

1. For winter stocking, choose a sunny morning; for summer and autumn stocking, choose a sunny early morning or an overcast and rainy day, avoiding direct sunlight.

2. Before stocking shrimp seed, bathe them in 3% to 5% salt water for 10 minutes to kill parasites and pathogenic bacteria.

3. For shrimp seed purchased from other places, because they have been out of water for a relatively long time, they should be slightly treated before stocking. Soak the shrimp seed in pond water for 1 minute, lift them out and set them aside for 2 to 3 minutes, then soak again for 1 minute, repeating this 2 to 3 times, so that the body surface and gill cavity of the shrimp seed absorb enough water before stocking, to increase the survival rate.

4. In ponds raising Procambarus clarkii, appropriately polyculture some silver carp and bighead carp to improve water quality and make full use of feed resources.

 Scientific Feeding Techniques

Procambarus clarkii has omnivorous feeding habits and is relatively greedy. In feed feeding, grasp the following three points.

1. According to the nutritional needs of Procambarus clarkii at the same growth and development stages, properly combine and feed the feed. During the juvenile and young shrimp stages, Procambarus clarkii feeds on rotifers, cladocerans, copepods, and aquatic insect larvae; during the adult shrimp stage, it also feeds on animal feed and plant feed. After shrimp fry and shrimp seed are stocked, apply fertilizer in a timely manner to fertilize the water quality. During the rapid growth stage of Procambarus clarkii from August to October, feed more wheat bran, soybean cake, and green feed, and appropriately feed animal feed. From November to December, before Procambarus clarkii overwinters, mainly feed animal feed.

2. Feed according to the living habits and feeding characteristics of Procambarus clarkii. Procambarus clarkii is mostly active and forages at night, and has the habits of competing for food and being greedy. In feeding, persist in feeding once each morning and afternoon every day, with the afternoon feeding being the main one, accounting for 70% of the whole day's feeding amount; adopt the method of feeding with fixed quality, fixed quantity, and fixed time, feed enough and evenly, ensure every shrimp eats its fill, and avoid competing with each other for food.

3. Feed reasonably according to weather, water quality changes, and shrimp activity and feeding conditions. The suitable water temperature for the growth of Procambarus clarkii is 20 to 32 degrees C. From August to October, Procambarus clarkii has a large food intake, and the daily feeding amount can be arranged at 6% to 10% of the body weight of the shrimp in the pond, with dry feed or compound feed calculated at 2% to 4%, and appropriately increased or decreased according to weather, water quality conditions, and shrimp activity and foraging conditions. During continuous rainy weather or when water quality is too dense, feed less; when the weather is clear and fine, feed appropriately more; when a large number of shrimp are molting, feed less, and after molting feed more; during the season when shrimp are diseased, feed less, and when growth is normal, feed more. It is necessary both to let the shrimp eat their fill and eat well, and to reduce waste and improve feed utilization.

Daily Management of Crayfish

1. Establish a pond patrol inspection system. Patrol the pond every day and take timely countermeasures when abnormalities are found.

2. Regulate water quality. Keep the dissolved oxygen in the shrimp pond above 5 g/L, pH 7 to 8.5, and transparency around 40 cm. Change water once every 15 to 20 days, changing 1/3 each time. Splash quicklime water once every 20 days, using 10 kg of quicklime per mu each time. Keep the water level stable and do not let it rise and fall abruptly.

3. Strengthen the management of habitat and molting sites. Always maintain a large amount of aquatic plants in the shrimp pond. When a large number of shrimp are molting, disturbance is strictly prohibited; after molting, immediately increase feeding of high-quality palatable feed to prevent mutual killing and promote growth.

4. Prevent escape and disease. Strengthen inspections during the flood season and strictly prevent shrimp from escaping. Do a good job in disease prevention and control and in removing enemies.

 Commercial Shrimp Harvesting and Transport

1. Harvesting. Concentrated harvesting can be done from June to July and from November to December. First use tools such as ground cage nets and hand nets to catch them, and finally drain the pond to catch them. You can also harvest the large ones and leave the small ones, harvesting year-round.

2. Transport. Commercial shrimp are usually transported dry in foam plastic boxes, or transported in plastic bags, or transported in refrigerated trucks. During transport, keep the shrimp body moist and do not press them, to increase the survival rate during transport.

Through the above introduction by the editor, everyone must have gained a general understanding of crayfish farming. I hope this can help new farming friends, but the editor suggests that the best way to learn is still to communicate and learn more with successful people.