Will high temperatures affect the listing of river crabs

Gucheng Lake Crab Pond Photo

Yangzi Evening News (Reporter Jiang Jingyi) Recently, Nanjing has continued to have high temperatures, and the highest temperature in some areas can reach more than 40 degrees. Will the river crabs that will be listed in September be affected? Xing Wenxiang, director of the Aquatic Products Technology Promotion Station of Nanjing Gaochun District, told reporters that the suitable water temperature of crabs is 15-25 ° C. Continuous high temperature will cause crabs to be unable to molt normally. In this regard, they responded through various methods such as adding water cooling, booting oxygen, nursing water plants, and regulating water quality. This year's Gucheng Lake Crab is expected to be officially launched in early September.

The reporter learned that high -temperature weather has no impact on the crab pond. The first is that it has a great impact on water plants, especially in Iraza. At present, most of them have basically dangled. The vitality of black algae and bitter grass is weakened. The higher the temperature, the lower the solubility of the oxygen, and the long -term high temperature can easily lead to hypoxia. Continuous high temperature and hot weather will make the water bait and metabolites in the water body not effectively decomposed, while the death of water plants and rotten the water plants have severely weakened the water purification capacity of water plants, causing the water quality and bottom quality of the pond to continue to deteriorate and breeding cyanobacteria.

In addition, the crab is a warm crustacean. It has a suitable growth water temperature to 15-25 ° C. When the water temperature exceeds 30 ° C, its feeding decreases, and the water temperature that continues to exceed 33 ° C will occur. Normally grow molten shells to cause casualties.

Before the end of February this year, Gao Chun Gucheng Lake crab seedlings all ended up, and a total of 228 million were released. At present, the river crab has begun for the fifth time. In order to ensure the healthy growth of the crab, "the crab pond must add water to the water level in time, add the water level of the pond to the highest bit, which helps to reduce the underlying temperature. And the water adding time is also particular. It should not be too long when adding water, 1-2 hours. "Xing Wenxiang introduced that the pond with exogenous water differences is less or not.

In response to the hypoxia of the pond, pay special attention to the dissolved oxygen in the high temperature season. Pay attention to oxygen and at night, and when the weather is sweltering, the oxygen increase equipment is opened throughout the day to ensure that the pond is sufficiently soluble. The Iraza in the deep water area of ​​the pond ditch must also be cleared in time. The waterweeds that grow on the dwarf surface on Bantian must be cut to cut the head, which is conducive to the flow of the pond water, prevent the water grass from being too dense to cause the pond hypoxia, keep the pond waterweed coverage The rate is 50-60%. Crab farmers should remove the floating water plants that were cut off by river crabs in time to prevent water grass from rot and corrupt the water quality.

The problem of aquatic plants is solved, and the water quality must be guaranteed. Xing Wenxiang suggested that the 7 angels of crab farmers use a micro -ecological agent and base quality improvement agent to promote the reproduction and growth of the beneficial bacteria, inhibit harmful pathogen, keep the pond water stability, and eliminate the outbreak of cyanobacteria; Toxic and harmful substances produced by bait, feces, etc., create a good ecological environment for river crabs. In terms of feeding, the amount of ice and fresh fish should be appropriately reduced in the high temperature season, and the feeding ratio of green feed (soybean meal, corn, wheat, etc.) is increased. Poetry such as vitamins and calcium can be added to bait feeding to enhance the body's immunity and improve the disease resistance of crabs.

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