How much does crayfish seed stock cost per jin, and how should you farm them?

Crayfish live in shallow wetlands, lakes and ditches rich in aquatic plants. They are widely popular for their delicious meat, and because they are omnivorous, grow quickly and adapt strongly, they have never lacked entrepreneurial investors. In recent years they have become an important economic farming species in China, so how much does crayfish seed stock cost per jin? How do you farm them?

1. How much does crayfish seed stock cost per jin

The market price of crayfish seed stock is about 15 to 30 yuan per jin. It is worth noting that the crayfish currently referred to are all one species; there is no such thing as a “hybrid variety”, because the cost is too high and natural seed stock is currently abundant and cheap, while artificially bred seed stock is still at the laboratory stage. Also, do not be misled into buying breeding crayfish at high prices from other places on the belief that they are a new variety that has been domesticated and shows less cannibalism. At the same time, many people think that after stocking breeding crayfish in the first year, they can rely on the crayfish's own continuous reproduction to obtain good returns year after year. In fact, crayfish farming yields the highest output in the first year after stocking, and then declines year by year, because the crayfish life cycle is 16 to 18 months; add in inbreeding, functional degeneration and reduced disease resistance, and after 3 years the output will drop sharply or even result in total crop failure.

2. Is farming crayfish profitable

Now taking a stocking rate of 40 jin of breeding crayfish per mu as the base for a rough estimate: the number of female crayfish producing offspring per mu per year is stocking amount 40 jin/mu × 10 per jin = 400 per mu. Calculating on the basis that 50% survive and spawn, 400 per mu × 100 per spawning × 2 times/year × 80% = 64,000 per mu/year. The survival rate from spawning to growing into juvenile crayfish is 8% to 30%; calculating at the lowest 8%, the total annual output of adult crayfish is 64,000 per year × 8% = 5,120 per mu/year. Each adult crayfish grows to 50 grams (about 10 per jin). The total annual output per mu is 5,120 per mu/year ÷ 10 per jin = 512 jin/mu/year. At 6 yuan/jin, the annual gross profit per mu is 512 jin × 8 yuan/jin = 4,096 yuan/mu. Net profit = gross profit 4,096 yuan - seed purchase cost (40 jin × 50 yuan) 2,000 yuan = 2,096 yuan/mu.

3. How do you farm crayfish?

1. Choosing a pond

Crayfish farming requires a water source with fresh water quality, sufficient dissolved oxygen and no pollution. The pond bank should be more than 3 m wide, and the pond area should not be too large; generally 3 to 8 mu is suitable. It is worth noting that crayfish have a strong ability to escape, so escape-prevention facilities must be properly built.

2. Pond clearing and disinfection

Pond clearing and disinfection can effectively kill harmful organisms in the pond (catfish, loach, snakehead, snakes, rats, etc.), wild miscellaneous fish that compete for food (carp, crucian carp, etc.) and pathogens. Quicklime and bleaching powder can be used; they are economical, affordable and safe.

3. Planting aquatic plants

Aquatic plants occupy a pivotal position in crayfish farming. Generally they should cover half of the pond area. Options include short-stemmed reeds, wild rice stem, Elodea and Hydrilla verticillata. If conditions permit, some empty cans, bamboo tubes, tree roots, etc. can also be placed at the bottom.

4. Fertilizing the crayfish pond

Before stocking crayfish, apply an appropriate amount of organic fertilizer to the crayfish pond to cultivate food organisms, which can directly provide natural feed after the crayfish enter the pond. However, the amount and timing of fertilization should depend on whether the water is rich or lean, and the pond water transparency should be kept at about 35 cm.

5. Stocking crayfish

Crayfish seed stock is stocked either in spring or autumn. The crayfish are required to be uniform in size, with complete appendages, free of disease and injury, and stocked all at once in sufficient quantity. Before stocking, bathe them in 5% salt water for 5 to 10 minutes to kill parasites and pathogenic bacteria.

6. Choosing feed

Crayfish are omnivorous. Animal-based feed mainly includes small fish pieces, dried fish meal, snail and mussel meat, and various animal organ scraps. Plant-based feed mainly includes rapeseed cake, soybean meal, wheat bran, wheat, corn, pumpkin, and various vegetables and aquatic and terrestrial grasses.

7. Feeding feed

Crayfish mostly move about and forage at night. Feed once each at 10 a.m. and 4 p.m. every day. The afternoon feeding amount accounts for about 70% of the whole day's feeding amount. The daily feeding amount can be appropriately increased or decreased according to the weather, water quality conditions and the crayfish's activity and foraging situation.

8. Daily management

In crayfish farming, you should patrol the pond every day and pay attention to changes in water color and crayfish activity. If crayfish are found on the bank or climbing on aquatic plants and refuse to enter the water when driven, check whether the water lacks oxygen or the water quality has deteriorated, and take corresponding measures such as increasing oxygen and changing the water.