The preserved artemia eggs of the Artemia can be left to hatch in fresh seawater at any time. The level of hatching rate does not completely depend on the different geographical lines of Artemia, but also on the process of egg processing and preservation, the containers used for hatching, the environmental conditions during hatching, and the density of eggs. The hatching effect is generally judged according to the hatching density of the egg. One gram of dormant eggs is about 200,000 - 300,000 tablets. The suitable hatching density differs depending on the hatching conditions. Incubators with a flat bottom and a large bottom area are used because the eggs are squeezed into the corner when inflated. The hatching efficiency is poor. Each litre of water can only hatch 0.1 to 1 g, using a funnel-shaped incubator. Bottom ventilation, hatching can reach high density.
For example, a 75-liter container in the form of a cylindrical transparent PVC can be used, and the hatching density can reach 5 g/L. This kind of transparent funnel-shaped hatching tank usually has a capacity of 0.5-1 tons. When it is hatched in large quantities, the maximum density cannot exceed 10 g/L. It is most convenient to hatch dormancy eggs with a natural sea (about 30 ç› salinity), and salinity can be hatched at 5-70 。. The optimum temperature for hatching is 25-30°C, which is the fastest to hatch at 30°C and must be warmed in winter. The cold-stored dormant eggs should be incubated at room temperature for a period of 1-2 weeks before hatching. Otherwise, the harvest rate of high-quality nauplii is low. During the incubation, air with a constant pressure should be continuously fed from the bottom of the incubator to keep the eggs. Suspended condition. In a 75 liter tank, about 20 liter/minute ventilation, you can maintain 2 mg/liter of dissolved oxygen. The dissolved oxygen is generally kept at 2-8 mg/l. The hatching speed of eggs is stable, and the hatching of egg is completely stopped when the egg is low to 0.6-0.8 mg/L. Illumination not only affects the hatching rate of eggs, but also affects the hatching speed of eggs. Continuous illumination with 1000 lux can obtain better results. For 75 liters sinks, use 4 60-watt fluorescent tubes and continue to light the hatching suspension at a distance of 20 cm. Contain the organic impurities in the dormant eggs. Pre-fill them with tap water before placing them in the hatchery container. After immersing for 1 hour, rinse eggs of Artemia cysts thoroughly on a 125 micron mesh screen. Remove the impurities and place them in the hatching water. The pH of the incubation water should be kept above 8. Generally, when the conditions are suitable, the resting eggs hatch into nauplii within 1-2 days. Stop the ventilation and cover with a light-tight container lid. Stop for a few minutes (5-7 minutes) before harvesting. The nauplii have a positive phototaxis and can coat the upper part of the funnel-shaped incubator with a black cloth or a total turnover, so that the light can only reach the lower part of the container, and add saturated salt water or coarse salt to increase the salinity. In this way, the empty shell floats to the uppermost part of the container, and sediments to the bottom of the funnel are the residue and unhatched eggs. The nauplii are concentrated under the light-transparent container. Open the stopper below and take out the unhatched eggs and residues. Then use the siphon method to extend the tube with the hammer to the light and recover the nauplii. In the larvae recovered by the above method, if there are still many unhatched eggs and egg shells, the recovered nauplii and eggs can be put together in an incubator equipped with clean sea water, and then recycled again according to the above method. Cleaner Artemia larvae can be isolated.
When Artemia nauplii is mixed with egg shells and unhatched eggs, when feeding fish and shrimp larvae, it will not only deteriorate the water quality, but also fish and shrimp larvae will eat egg shells and unhatched eggs, which will cause ileus, even Death, therefore, must be separated from the bad eggs and egg shells, in addition, before feeding, in order to prevent glycerol, hatched metabolites and bacteria contaminated fish, shrimp nursery ponds, the nauplii should be placed on a 125 micron sieve, fully After the wash, feed again.
For example, a 75-liter container in the form of a cylindrical transparent PVC can be used, and the hatching density can reach 5 g/L. This kind of transparent funnel-shaped hatching tank usually has a capacity of 0.5-1 tons. When it is hatched in large quantities, the maximum density cannot exceed 10 g/L. It is most convenient to hatch dormancy eggs with a natural sea (about 30 ç› salinity), and salinity can be hatched at 5-70 。. The optimum temperature for hatching is 25-30°C, which is the fastest to hatch at 30°C and must be warmed in winter. The cold-stored dormant eggs should be incubated at room temperature for a period of 1-2 weeks before hatching. Otherwise, the harvest rate of high-quality nauplii is low. During the incubation, air with a constant pressure should be continuously fed from the bottom of the incubator to keep the eggs. Suspended condition. In a 75 liter tank, about 20 liter/minute ventilation, you can maintain 2 mg/liter of dissolved oxygen. The dissolved oxygen is generally kept at 2-8 mg/l. The hatching speed of eggs is stable, and the hatching of egg is completely stopped when the egg is low to 0.6-0.8 mg/L. Illumination not only affects the hatching rate of eggs, but also affects the hatching speed of eggs. Continuous illumination with 1000 lux can obtain better results. For 75 liters sinks, use 4 60-watt fluorescent tubes and continue to light the hatching suspension at a distance of 20 cm. Contain the organic impurities in the dormant eggs. Pre-fill them with tap water before placing them in the hatchery container. After immersing for 1 hour, rinse eggs of Artemia cysts thoroughly on a 125 micron mesh screen. Remove the impurities and place them in the hatching water. The pH of the incubation water should be kept above 8. Generally, when the conditions are suitable, the resting eggs hatch into nauplii within 1-2 days. Stop the ventilation and cover with a light-tight container lid. Stop for a few minutes (5-7 minutes) before harvesting. The nauplii have a positive phototaxis and can coat the upper part of the funnel-shaped incubator with a black cloth or a total turnover, so that the light can only reach the lower part of the container, and add saturated salt water or coarse salt to increase the salinity. In this way, the empty shell floats to the uppermost part of the container, and sediments to the bottom of the funnel are the residue and unhatched eggs. The nauplii are concentrated under the light-transparent container. Open the stopper below and take out the unhatched eggs and residues. Then use the siphon method to extend the tube with the hammer to the light and recover the nauplii. In the larvae recovered by the above method, if there are still many unhatched eggs and egg shells, the recovered nauplii and eggs can be put together in an incubator equipped with clean sea water, and then recycled again according to the above method. Cleaner Artemia larvae can be isolated.
When Artemia nauplii is mixed with egg shells and unhatched eggs, when feeding fish and shrimp larvae, it will not only deteriorate the water quality, but also fish and shrimp larvae will eat egg shells and unhatched eggs, which will cause ileus, even Death, therefore, must be separated from the bad eggs and egg shells, in addition, before feeding, in order to prevent glycerol, hatched metabolites and bacteria contaminated fish, shrimp nursery ponds, the nauplii should be placed on a 125 micron sieve, fully After the wash, feed again.