Crayfish culture environment

When it comes to crayfish, what you might want to get first is that it's dirty, because you have to brush it clean before eating crayfish, so many people think that little dragons like to live in dirty environments. Is that true? Let's find out about it together with Xiaobian below!

Crayfish culture environment

Do crayfish like dirt? [Investigation] Poor vitality in dirty environment, difficult to reproduce Many netizens think, crayfish are often found in sewage ditch, whether this means crayfish like to inhabit dirty environment. Is that true?

Tang Jianqing, director of the breeding room of Jiangsu Province Freshwater Fisheries Research Institute, told reporters that their experiments showed that corrosive food and fresh food were placed in front of crayfish, and the ratio of corrosive food to fresh food was 1:10.

Huang Cheng, associate professor of the School of Life Sciences of Nanjing University, demonstrated a "maze experiment" to reporters: fill a 2-meter-long Y-shaped tank with clean water, place a sponge covered with ammonium chloride (common substance in dirty water) solution at the left front end of the tank, and place a sponge covered with clean water at the right front end. Then he placed a crayfish at the back of the tank. When the shrimp climbed along the tank to the junction of the path ahead, it tested left and right and finally chose to climb to the clear water tank on the right.

"It's unscientific to judge that crayfish like to live in dirty environments based on 'you can catch them in the sewage ditch, but you can't catch them in clean water'." Huang Cheng said that crayfish growing in clear water have strong vitality and are difficult to catch without tools, while crayfish in polluted environment have poor vitality and are difficult to reproduce.

Shu Xinya, senior engineer of Hubei Province Institute of Aquatic Sciences, believes that crayfish has strong tolerance and can survive in sewage, but crayfish need to shell seven or eight times during its growth process. If the environment is not good, crayfish will not shell and grow badly. Many farmers did not pay attention to the water environment before, using shallow water, dirty water culture, crayfish yield is very low; later pay attention to deep water, good water culture, yield increased.

Create a good environment for lobster growth. Lobster is a kind of insect shell animal, similar to crab, has a pair of specially developed pincers, has the habit of digging holes, generally digging holes near the water. Lobsters prefer shade and fear light. When the light is weak or dark, they climb out of the cave. When the light is strong, they sink to the bottom or hide in the cave. According to lobster habits, 50 cm high anti-escape nets can be added to the river pond to prevent lobster escape. At the same time, the river pond simulates the ecological environment of lobster under natural conditions, planting 10-15% of aquatic plants and shelters in the shallow pool to create an environment for lobster habitat and shelling, and reducing mutual killing.

The impact of water quality on lobster production cannot be ignored. The quality of water directly affects the healthy growth and development of lobster. In the breeding process, the pH value of the pool water should be kept between 7.5-8.5, and the transparency should be 30-40 cm. New water should be added frequently, and quicklime solution should be sprinkled regularly to adjust the water quality and prevent diseases and shelling failure.

What is the origin of crayfish?

Crayfish is a world-class invasive species, native to Central and South America and northeast Mexico. It was introduced into Japan in 1918 as bait for raising bullfrogs, and then introduced into China from Japan. Now it has become an important resource of freshwater shrimps in China, widely distributed in provinces and cities in the middle and lower reaches of the Yangtze River. In May 2013, it was reported that crayfish was introduced into China by the biochemical forces of the Japanese invaders that year to deal with corpses. This statement is pure rumor.

Crayfish is a kind of crustacean like lobster that lives in fresh water. Its scientific name is Procambarus clarkii, also known as red crayfish, freshwater crayfish and fighting shrimp. Crayfish is the most widely distributed invasive alien species in crustaceans. Crayfish has absolute competitive advantage in local ecological environment because of its omnivorous, fast growth speed and strong adaptability. Their feeding range includes aquatic plants, algae, aquatic insects, animal carcasses, etc. When food is scarce, they also kill each other.

During World War II, crayfish was introduced into China from Japan and began to reproduce in Nanjing City and suburban counties of Jiangsu Province. After a long period of expansion, the population increased continuously and the living space expanded continuously. At present, crayfish has expanded to Anhui, Shanghai, Jiangsu, Hong Kong, Taiwan and other places, forming a large number of natural populations and becoming an important resource in freshwater shrimp in China.

What are the advantages of raising crayfish

1. Large market potential: The market demand for crayfish is very large. This tense market supply-demand relationship makes the crayfish industry have high economic benefits and broad development prospects, and sales are not a problem.

2. Low breeding difficulty: crayfish has strong adaptability to the environment, few diseases and low oxygen tolerance. It can not only carry out high-density cultivation of small water bodies in ponds, but also naturally proliferate in various water bodies such as rivers, lakes, rice fields and swamps. The breeding technology is simple.

3, low breeding cost: crayfish food miscellaneous, bait easy to solve, in low-density breeding without feeding special feed, faster growth rate, high yield, high energy conversion rate, low breeding cost, good benefits.

4. Short breeding cycle: crayfish can be listed on the market after about 2 months of breeding. Circular breeding can be adopted through the technical scheme of catching large and keeping small, belonging to the breeding mode of one-time investment and perennial benefit.

Crayfish rearing and management techniques

1. Select pond: The water source for crayfish cultivation requires fresh water quality, sufficient dissolved oxygen and no pollution. The pond ridge width is more than 3 meters. The pond area should not be too large, generally 3~8 mu is appropriate. It is worth noting that crayfish have strong escape ability, so we must do a good job in the construction of escape prevention facilities.

2, pond disinfection: pond disinfection can effectively kill the pool of enemy organisms (catfish, loach, snakehead, snake, rat, etc.) and compete with the wild fish (carp, crucian carp, etc.) and pathogens, you can use quicklime and bleaching powder, economic, affordable and safe.

3. Planting aquatic plants: aquatic plants play an important role in lobster cultivation. Generally, half of the pond area is suitable. Low-stem reed, Zizania latifolia, Elorea verticillata, Hydrilla verticillata, etc. can be selected. If conditions permit, some empty cans, bamboo tubes, roots, etc. can be placed at the bottom.

4. Fertilization of shrimp pond: Apply proper amount of organic fertilizer to shrimp pond when lobster is stocked, cultivate bait organisms, and provide natural bait directly for shrimp after entering the pond, but the selection of fertilizer amount and time depends on the fat and thin of water, and the transparency of pool water is maintained at about 35 cm.

5. Lobster stocking: lobster fry is divided into spring and autumn. It is required to be neat in specification, complete in appendages, disease-free and injury-free. It is required to put enough at one time. Before stocking, bathe with 5% edible salt water for 5~10 minutes to kill parasites and pathogenic bacteria.

6. Feed selection: Lobster is omnivorous. Animal feed mainly includes small fish fragments, dried fish meal, snail meat and various animal offal scraps. Plant feed mainly includes rapeseed cake, soybean meal, bran, wheat, corn, pumpkin and various vegetables and drought grass.

7. Feed feeding: crayfish mostly feed at night, feeding once at 10:00 a.m. and 4:00 p.m. every day. The afternoon feeding amount accounts for about 70% of the feeding amount of the whole day. The daily feeding amount can be appropriately increased or decreased according to the weather, water quality conditions and shrimp activity foraging conditions.

8. Daily management: crayfish breeding should patrol the pond every day, pay attention to the change of water color and lobster activities. If shrimp is found ashore or climbing on water grass to drive them away and refuse to enter the water, check whether the water body is oxygen-deficient or the water quality is deteriorated, etc., and take corresponding measures, such as oxygenation and water change.

Through the above analysis, we can see that crayfish do not like to live in dirty environment as we think. Facts prove that crayfish in dirty environment have poor vitality and are difficult to reproduce. Crayfish in clear water are active and difficult to catch without tools. Therefore, crayfish do not like to live in dirty environment.