1, mixed culture mode of shrimp and rice, 1 mu 1 year can usually produce about 160-200 kg. The mixed culture mode of shrimp and rice will cause crayfish to be in an unfavorable growth environment in high temperature season, resulting in low crayfish yield. 2. Pond intensive cultivation mode, 1 mu 1 year can usually produce about 300-400 kg, and sometimes it can reach more than 500 kg. 3. Culturing crayfish must maintain a reasonable density, so as to increase the yield.

1. How many catties can crayfish produce per acre of land a year?

1, in the shrimp-rice polyculture mode, the yield per mu 1 year is about 160-200 kg, and crayfish in the shrimp-rice polyculture mode will be affected by rice planting, growth and other factors, which will make crayfish in an unfavorable growth environment in high temperature season, resulting in low yield. Generally, the output of shrimp fry is about 150-200 kg when 60-70 kg is put in. If it wants to reach more than 250 kg, it is necessary to do a good job of fry breeding in autumn and winter every year, so that there are enough shrimp fry in the breeding pond in the second year, and at the same time, it is necessary to put them in properly according to the actual breeding situation.

2. Under intensive pond culture mode, the yield per mu of land 1 year is generally about 300-400 kg, and sometimes it can reach more than 500 kg. The output of intensive culture pond mouth, which mainly breeds shrimp seedlings, will be higher. As the intensive culture mode of pond can adopt the farming mode of catching and releasing by turns,/kloc-0 can breed crayfish for more than 2-3 seasons per year, so the output will be increased accordingly. Using this method requires rich farming experience and meticulous management, and farming risks are also relatively large.

3. If you want to increase the output of crayfish, you must maintain a reasonable culture density. Appropriate culture density can not only give full play to the main productivity of the pond, but also improve the output, specifications and economic benefits of shrimp. If we blindly pursue the breeding density, it will not only increase the difficulty of breeding, but also lead to the phenomenon of crayfish killing each other. Moreover, under high-density culture, a large amount of residual bait and crayfish excrement will pollute the water quality, resulting in a decrease in the living space of crayfish.

Second, crayfish culture methods and environment

1, crayfish culture method

(1) Breeding site

1 Although crayfish have strong adaptability to water quality, the main purpose of culture is to provide food, so the water quality of the culture pond must be clear and pollution-free, and rich in dissolved oxygen.

It is necessary to set up water changing facilities and oxygen increasing equipment for the pond, and make corresponding measures in time for emergencies.

3. Take measures to prevent the escape at the entrance and exit of the pond, so as to prevent the phenomenon of escape during the breeding process.

(2) pond cleaning and disinfection

1 The pond must be cleaned and disinfected, which can effectively remove harmful substances, pathogens and parasites, reduce pathogens and reduce the incidence rate.

Remove the natural enemies of crayfish in the pond, such as snakes and rats. At the same time, it is also necessary to prevent fish in the pond, because fish will compete with crayfish for food, which will affect the normal growth and development of crayfish. For disinfection, quicklime can be sprinkled all over the pond.

(3) Planting aquatic plants

1 Aquatic plants play an important role in crayfish culture. Appropriate amount of aquatic plants can be planted at the stem and bottom of the pond, which can effectively increase the dissolved oxygen content in the pond and provide a place for crayfish to rest and shade.

2 The planting area of aquatic plants should not be too large, and it should not exceed 1/2 of the pond at most. Too much will affect the nutrient absorption of crayfish, and some bottles or bamboo tubes can be placed at the bottom of the pond for crayfish to inhabit.

(4) Fertilizer application

1 Before stocking, it is necessary to apply a proper amount of fertilizer in the shrimp pond, so that plankton can be cultivated and crayfish can freely prey on plankton.

2 Too much fertilizer should not be used, which will cause crayfish diseases. The specific dosage can be determined according to the fertility of the pool water and the pond area, and the pool water should be kept transparent, which is beneficial to the later management observation.

(5) stocking shrimp fry

1 The stocking time of shrimp seedlings must avoid the two extreme temperature seasons of summer and winter. The specifications of shrimp seedlings should not be uneven, and shrimp seedlings with good growth and no disease must be selected.

2 stocking does not need to be carried out in batches, and it can be put in all at once.

Before stocking, the prawn seedlings need to be disinfected to eliminate parasites and germs, and the prawn seedlings can be soaked in salt water.

(6) Feed selection

1 Lobster's feeding habits are very diverse and extensive, and it can be fed with broken shell snail meat, mussel meat or animal viscera.

2 You can't put a single meat feed, but you need to mix it with plant feed such as corn and wheat.

Crayfish are generally free to feed at night, and can be fed twice a day, and the frequency is appropriately increased according to the growth and weather conditions.

2. Crayfish culture environment

(1) pond water temperature

1 crayfish has low requirements on water temperature, and it can survive as long as the water temperature is around1-40 C. Its growing water temperature is above10 C, the suitable water temperature is around16-33 C, and the optimal water temperature is around 20-32 C.. However, when the temperature is lower than 20°C or higher than 32°C, the growth rate of crayfish will decrease.

20% of shrimps have a certain tolerance to high and low temperatures. In winter, crayfish will crawl out of the cave for food, but when the water temperature is lower than10 C, they will dive into the cave for winter. When the water temperature is higher than 33°C, crayfish will enter the deep water area during the day and feed in shallow water or grass at night.

(2) dissolved oxygen in pond

Crayfish can adapt to the very harsh ecological environment in natural waters, but it must meet two preconditions, namely, there are abundant natural bait in the water body, and the dissolved oxygen in the water body should not be too low.

(3) the acidity and alkalinity of water quality

1 When crayfish are cultured artificially in the pond, its requirements for the pH value of the cultured water body should be slightly alkaline, which is basically similar to that of fish.

The water with a pH of 7-9 is the best environment for the growth and reproduction of crayfish. When raising crayfish, it is necessary to adjust the pH of the water, which can be adjusted by using brown sugar or quicklime.

(4) Heavy metal ions

1 Crayfish can't be exposed to heavy metal ions, which will have a serious toxic effect on crayfish.

There are two main ways of poisoning: first, the combination of heavy metals and protein in organisms inhibits the activity of yeast plum, which directly destroys the normal physiological function of crayfish; Second, the combination of heavy metals and gill mucosa will destroy gill tissue, hinder breathing, and lead to crayfish suffocation and death.