Preliminary work of crayfish culture

If you want to have a good harvest, the preliminary work of crayfish culture is very important.

1. Pond transformation: crayfish culture is soil, water quality and size.

(1) soil quality: it can not be pure sandy soil, sandy soil is not suitable for seed conservation, and harder soil is not suitable for the proliferation of seedlings.

(2) Water source: where the water source is not good, directly drill wells to draw water.

(3) size: the size of Tangkou should be easy to manage (Tangkou is too large to be managed, Tangkou is too small and the management cost is high). In general, 10 mu of ponds and 30 mu of paddy fields are suitable.

2. Pond reconstruction standards: deep ditch, shallow platform, gentle slope. Standard Tangkou should ensure that the aquaculture water level can reach 70 cm, which is convenient for production management. 70 cm is both a nutrient layer and a dissolved oxygen layer. In addition, moss, fertile water, oxygen enrichment or crayfish molting in the pond are all related to the depth of the water; the water is not deep and is not conducive to crayfish fishing.

(1) the ridge of the pond is high: the ridge of the pond should be 1.5 meters high.

(2) ditch width: the trench should be dug to 6 meters wide.

(3) Pond width: not more than 60 meters wide.

3. Plant good aquatic plants: only when the grass is well planted can the seedlings be released.

(1) the periphery of the ditch is planted with water peanuts; the bottom of the ditch is planted with bitter grass (the planting of bitter grass should be adjusted to local conditions and the planting time is determined according to the water depth); verticillium verticillata is planted on one side of the ditch; "eat invincible" or shrimp grass is planted on the platform (Potamogeton crispus, which begins to die when the wheat is yellow in May, so it is also called wheatgrass, because it is synchronized with the crayfish "autumn, winter and spring" season, so it is also called shrimp grass); interplanting verticillium verticillata in ponds. (2) spin, leave the way, and return to the position of the fallen leaves. (3) Live the root first, then the leaf; the root has fertilizer, and the leaf has leaf fertilizer.

4. planting and releasing seedlings: the first is to look at shrimp, and the second is the standard of putting in seeds and releasing seedlings.

Look at the size: "Fish species are neat, crayfish are uneven." The more uneven the crayfish seedlings are, the more batches they are. The more batches, the more the quantity; the more the quantity, the higher the output. In addition, the larger the proportion, the more high-priced shrimp will be available in March. Second, look at the body color: the crayfish is green, which means adequate nutrition; the body color is red, which means poor nutrition. Third, look at the body: the body is plump, the wider the tail, the stronger the vitality.

(1) 15 kg per mu of new pond and no more than 10 kg of mu of old pond.

(2) the first 5 kg per mu of Xintang, and then 10 kg in two days. After the release of seedlings, the whole pond was sprinkled with "silver roses". After 20 days, about 10 kg can be released (in this way, 4-5 batches of seedlings can be released each year, for a total of 40-60 kg).

(3) to replenish seedlings in the old pond, calculate and put them according to the number of adult shrimps caught, using the "day and night" method.

(4) the number of wild crayfish seedlings is small, after many times of hoarding and poor physique, so wild crayfish seedlings need to be purchased carefully. In the selection and purchase of wild crayfish seedlings, it is appropriate to choose green shell shrimp, to remove the red shell, empty shell crayfish molting is more difficult, the mortality rate is high.

(5) from July to August, the green-shell prawns were used as parents and bred and propagated in their own pond mouth, with 15,25kg per mu, and the parent crayfish was caught in November.

(6) the cave should be artificially assisted at the mouth of the pond where the parent crayfish is released or not caught after October.

5. Molting and calcium supplement: crayfish grow by molting. Crayfish culture molting period is generally only 3-4 times, in order to increase the yield, as long as an increase in molting, the yield can be doubled. For example, Tangkou, which has an output of 50 kg at the breeding level, finds a way to exuviate its shell one more time, and the output can reach 100 kg, but it only takes about half a month. Molting needs calcium supplement, once a week. Crayfish molt every day, so you can't kill moss (moss net is prohibited during molting).