Fry breeding period In the hatching process of fish fry, the phenomena of early release and malformation of embryo occur occasionally, which seriously affects the emergence rate. The rough wall of the hatching tank must be smoothed with a grinding wheel, and the proper density should be kept when laying eggs. Generally, about 800,000 eggs are laid per cubic meter of water. The hatching water should be clean without pollution and have a large flow; The lime slurry can be adjusted in the reservoir to maintain the pH between 7 and 8. If a small amount of fish eggs in the hatching pond are found to be removed in advance, the small inlet valve can be closed and the permanganate can be properly closed. Potassium solution was poured into the hatching tank, so that the pool water showed a concentration of 5ppm to 10ppm, and kept for 5 minutes to 8 minutes. After treatment, the egg membranes of the fish eggs became firmer, not easily damaged, and had the effect of preventing premature release. Over-ripened fish eggs, as well as fish eggs produced by malnourished broodstock, are most likely to form deformed embryos. Changes in temperature, especially at the fertilization stage of the eggs, at the beginning of cleavage, and before and after the release of the membrane, can lead to an increase in abnormal embryos. Poor hatchery water quality also affects the normal development of the embryo and produces deformed embryos. Therefore, once a year's fry breeding work, it is necessary to do a good job of broodstock breeding, but also to select the right timing and the right weather for broodstock production. Sword mink is the biggest enemy of fry incubating stage. When it invades a large number of hatching pools, it will bite fish eggs or bite dead fish. Therefore, spawning ponds and hatchery pools must be strictly filtered. If it is found that there is a large amount of water in the hatchery, the small inlet valve can be closed appropriately, and the amount of water in the fish egg can be rolled and not sinking. The plastic bottle containing 90% crystal trichlorfon is used to drill a few holes. Hang on the water supply port of the reservoir to the hatchery to kill Jianshui. Denture Box Serries,Denture Storage,Denture Storage Case,Denture Cases Boxes Ningbo Carest Medical Instrument Co.,ltd , https://www.carestmed.com