A couple of days ago in the Daily Lecture I published an article titled "Farming Techniques | What do rural crayfish farmers need to pay attention to in early spring? How to farmcrayfishwithout losing money" (click to read that content), and the response was very good. Some friends left messages in the back end asking me to share more, so today I will share 7 methods for successfully farming crayfish.

The most suitable growth temperature for freshwater crayfish is above 18℃ and below 30℃, but when the water temperature is below 5℃, they will suffer frostbite and freeze to death, causing losses. At the very bottom of the article we will talk abouthow to let crayfish overwinter safely when the weather turns cold.

The complete collection on how to scientifically farm crayfish

First, pond aquatic plants.

Grass is crucial for shrimp and crabs. As the saying goes: "To judge a crab's size, look at the aquatic plants"; "To judge how many shrimp there are, look at the aquatic plants." "To know whether the crayfish are good, see whether there is grass in the pond. To know whether the crayfish are big, the grass in the pond is the key." Aquatic plants hold a pivotal position in crayfish farming. First, aquatic plants can make up for insufficient food intake by crayfish and supply a large amount of vitamins; second, they can block wind and waves, absorb some harmful substances in the water, purify water quality, and balance the water environment; third, they can provide hiding and resting places for young shrimp and molting shrimp, reducing bullying of the weak by the strong. Generally, the area planted with aquatic plants should preferably account for half of the total pond area. Varieties can include: low-stem reed, wild rice stem, Elodea, Hydrilla verticillata, etc. If conditions permit, some empty cans, bamboo tubes, tree roots and other discarded items can also be placed at the bottom of the water; these are all favorite habitats for crayfish.

Second, stocking density.

Some people who have never farmed crayfish think that the more they stock, the better, and that some will die anyway. Actually, this is not the case. If the crayfish stocking density is too high, water quality is prone to rapid deterioration,oxygen deficiency causing them to climb onto the grass, large amounts of grass being clipped off, and cannibalism when food is lacking.

Calculated at 100 tails/jin, that is 10,000 tails/mu, 100 jin/mu. A little more or a little less does not matter, as long as the difference is not large.

Third, feeding time.

Generally feed 2 times, once in the morning and once in the evening. Generallymore is fed in the evening, accounting for 80% of the whole day. The feeding amount should be determined according to water temperature, the shrimp's feeding situation, weather, shrimp size (size, growth stage), stocking density, water quality, season, etc.

It is recommended to set up feeding trays at the edge of the shrimp pond so as to observe feeding conditions, avoid cannibalism caused by insufficient food and waste caused by too much food, which also pollutes the water quality. Generally, it is best if the food is finished in about 2 hours.

Fourth, pond 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. The specific operation methods are: 1. Quicklime disinfection. Dry disinfection: use 70 kg of quicklime per mu, dissolve it in water and splash it over the whole pond; if conditions permit, rake it over with a rake, and after one week of pond drying, inject new water. Disinfection with water present: calculated at a water depth of 1 m per mu of water surface, use 130 kg of quicklime dissolved in water, then splash it evenly over the whole pond. 2. Bleaching powder disinfection. After completely dissolving bleaching powder containing 30% effective chlorine, splash it evenly over the whole pond, with a dosage of 25 kg per mu.

Fifth, regular fertilization

Some people think it does not matter whether the pond for farming crayfish is fertilized or not. In fact, before stocking crayfish, applying an appropriate amount of organic fertilizer to the shrimp pond cultivates food organisms and can directly provide natural food after the shrimp enter the pond. Use 400 kg/mu of fermented organic fertilizer to maintain the corresponding fertility of the pond water. During the rearing process, as the water level gradually deepens, apply decomposed organic fertilizer as a top dressing. The amount and timing should be chosen according to whether the water is fertile or lean, and generally no more than 80 kg each time is appropriate. The transparency of the pond water should be maintained at about 35 cm.

Sixth, scientific stocking

Based on the current crayfish farming techniques, shrimp fry stocking mainly includes three stages: first, stocking autumn fry, commonly known as "stocking seed shrimp"; second, spring fry, commonly known as "spring shrimp fry"; third, summer supplementary stocking.

Seventh, choosing feed

Crayfish are omnivorous. Animal feed, plant feed, and various artificial feeds should be used in combination at different stages. Animal feed mainly includes small fish pieces, dried fish meal, snail and mussel meat, and various animal offal; plant feed mainly includes rapeseed cake, soybean meal, bran, wheat, corn, pumpkin, and various vegetables and aquatic and terrestrial grasses.

Finally, let's talk about how to let crayfish overwinter safely when the weather turns cold and temperatures drop. What problems must be solved for shrimp fry to overwinter?

Most areas have already seen rain and snow with strong winds, along with pond freezing, causing water temperatures that are too low or oxygen deficiency from partial pond freezing. Some shrimp fry have already hatched and left their burrows. If management is improper, it can cause mass death of crayfish.

1. Use water level and aquatic plants to regulate water temperature

The water level can be determined according to the weather. On sunny days, the water level can be controlled at about 1.5 m, letting the air temperature raise the water temperature. During continuous rainy weather, raise the water level in a timely manner to maintain the water body temperature. Note that in winter when water is scarce, try to keep the water level stable. Plant Elodea, Potamogeton crispus, evergreen Vallisneria, and other cold-tolerant submerged plants to raise the temperature at the bottom of the water.

2. Use biological fermentation to regulate water temperature

When microorganisms at the bottom of the pond ferment, they can also raise the water temperature. At this time, a small amount of farmyard manure can be used appropriately, or straw can be piled in the pond to promote fermentation of bottom organisms.

Click the Daily Lecture avatar,follow, to get more content,send us a private message with your comments