What preparatory work is needed in the early stages of crayfish farming

If you want a good harvest, the early-stage work of crayfish farming is very important.

1. Pond renovation: For farming crayfish, the first is soil quality, the second is water quality, and the third is size.

(1) Soil quality: It cannot be pure sandy soil; sandy soil is not suitable for maintaining stock; relatively hard soil is also not very suitable for the reproduction of seedlings

(2) Water source: In places with a poor water source, directly drill a well to pump water.

(3) Size: The size of the pond opening should be easy to manage (too large a pond opening is inconvenient to manage, and too small a pond opening makes management costs high). Generally, a pond of 10~20 mu is suitable, and 30~50 mu of rice fields is more suitable.

2. Pond renovation standards: deep ditches, shallow platforms, gentle slopes. A standard pond opening must ensure that the farming water level can reach 70 cm, for ease of production management. 70 cm is both the nutrient layer and the dissolved oxygen layer. In addition, the moss in the pond, fertilizing the water, aeration, or crayfish molting are all related to water depth; if the water is not deep, it is also not conducive to catching crayfish.

(1) Ridge height: The pond ridge should be made 1.5 m high.

(2) Ditch width: The ditch should be dug to 6 m wide.

(3) Pond width: It cannot exceed 60 m wide.

3. Plant water grass well: Only after the grass is well planted can seedlings be released.

(1) Plant water peanut around the outer edge of the ditch; plant Vallisneria (eelgrass) at the bottom of the ditch (Vallisneria planting should be adapted to local conditions, and the planting time should be determined according to water depth); plant Hydrilla verticillata on the side of the ditch near the rice fields; plant “chibubai” or shrimp grass on the platform (Potamogeton crispus, which begins to die in May when the wheat turns yellow, so it is also called wheat-yellow grass; because it is perfectly synchronized with the “autumn, winter, and spring” farming cycle of crayfish, it is also called shrimp grass); for dedicated ponds, Hydrilla verticillata should be interplanted. (2) Make rows, leave paths, and return fallen leaves to place. (3) First revive the roots, then the leaves; roots have root fertilizer, and leaves have leaf fertilizer.

4. Stocking and seedling release: First look at the shrimp, then the standards for stocking and releasing seedlings.

First, look at size: “Fish fry are uniform in size, while crayfish are uneven.” The more uneven the crayfish seedlings are, the more batches there are. The more batches, the greater the quantity; the greater the quantity, the higher the yield. In addition, the greater the proportion of large ones, the more high-priced shrimp there will be in March. Second, look at body color: If the crayfish body color is bluish, it indicates sufficient nutrition; if the body color is red, it indicates poorer nutrition. Third, look at body shape: A plump body and a wider tail indicate stronger vitality.

(1) For new ponds, stock 15 kg per mu; for old ponds, stock no more than 10 kg per mu.

(2) For new ponds, stock 5 kg per mu the first time, then stock 10 kg two days later. After the seedlings are fully stocked, splash “Silver Rose” over the whole pond. After 20 days, stock about another 10 kg (in this way, 4~5 batches of seedlings can be stocked each year, for a total of 40~60 kg of seedlings)

(3) For supplementing seedlings in old ponds, estimate the stocking amount based on the number of adult shrimp caught, using the “three in the morning, four in the evening” method.

(4) Wild crayfish seedlings are few in number and have poor physique after repeated hoarding, so wild crayfish seedlings should be purchased with caution. When selecting wild crayfish seedlings, it is advisable to choose blue-shelled shrimp, and remove red-shelled and empty-shelled ones; red-shelled and empty-shelled crayfish have greater difficulty molting and a high mortality rate.

(5) From July to August, stock large blue-shelled shrimp as parents, breed and reproduce them in your own pond, stocking 15~25 kg per mu, and in November the parent crayfish must be caught.

(6) After October, ponds where parent crayfish are stocked or where parent crayfish are not caught need artificial burrows.

5. Calcium supplementation during molting: Crayfish grow by molting. In crayfish farming, the molting period is generally only 3~4 times. If you want to increase yield, as long as you add one more molt, the yield can double. For example: for a pond opening with a farming level of 50 kg yield, if you find a way to molt one more time, the yield can reach 100 kg, and the time needed is only about half a month. Molting requires calcium supplementation, once a week. Crayfish molt every day, so moss cannot be killed (moss-clearing agents are prohibited during the molting period).