The hatching rate of some Artemia eggs is very low (some only reach 10-15%). In order to effectively use the hatching eggs with low hatching rate, hypochlorite solution is used to treat the eggs outside the dormant eggs. The hard shell (mainly composed of lipoprotein and heme) dissolves, using an egg with only a transparent membrane, the so-called shelled egg. The egg viability of the treated egg is not affected. Continuous insects hatched with shelled eggs can be directly fed or directly fed without hatching without separation.
Prior to the shelling operation, the shelling solution was prepared. (1) Add 50 ml of a 10% sodium hypochlorite solution to 80 ml of sea water. In order to keep the pH of the solution stable, add 1.3 g of hydroxide steel to match the shelling solution required for 10 g of egg. (2) Dissolve 20% 20% calcium hypochlorite (bleach powder) in 130 ml of water, inflate for 10 minutes, add 10 grams of sodium carbonate for industrial use (or calcium oxide), then inflate for 10 minutes, and place the solution overnight. Allow it to settle and cool. The next morning, the siphon was evacuated and used for the depilation of 10 g eggs. After bleaching for a period of time, the effective chlorine content will gradually decrease. It is prepared after the actual chlorine content is measured before use. For the preparation method of shelling solution, please refer to the articles of Li Maotang, Zheng Yan, et al.
The method of shelling is to put dry eggs into sea water or tap water with a salinity of 35 ‰ and a water temperature of 25 ,C. The container can be used as a funnel-shaped cylinder sink, and continuous air ventilation from the bottom to keep the eggs suspended and fully absorb water for 1-2 hours. After that, the eggs were spherical and the excess water was drained with a 125 μm mesh screen. The absorbed eggs were placed in a 0-4°C freezer for several hours or overnight. The hypochlorite shelling solution is then added. Keep 15-20°C lower temperature during processing. In particular when processing 500 g or more dormant eggs, the water temperature of the suspension should be regularly measured. The water temperature should be kept below 40°C so as not to affect the viability of dormant eggs. Tap water or ice can be used to cool down when necessary. During the treatment, it was inflated and agitated. The shell dissolved completely after 7-10 minutes, and the egg changed from dark brown to grayish white and finally to orange. After microscopy or seeing no change in color, and no longer rising in temperature, immediately move to a 120-micron nylon screen and rinse with filtered seawater or tap water until chlorine smells. Then place in a container of seawater or tap water (5-10 ml of water per gram of egg). Add 1-2% of sodium thiosulfate or 1-2% of sodium sulfite to dechlorinate, or immerse 2-3 times in 0.1N hydrochloric acid solution (3,7% concentrated hydrochloric acid, 8.2 ml plus 91.8 ml of distilled water). This dechlorination operation must be completed within 30 seconds. Finally, it should be rinsed with water. After processing, the shelled eggs should sink, the broken eggs, and the shelled eggs float. This can be removed from the water and left for processing. The eggs can be directly used for feeding fish and shrimp, and can also be stored in a refrigerator at -4°C or dehydrated and then placed in saturated saline for use. The shelled eggs were incubated with the hatched nauplii and had the same bait spatula. The unfavorable condition is that when the eggshell is removed, it cannot float, and it settles down quickly in the water. Therefore, it must be inflated after feeding to enable the shelled eggs to be suspended in water for easy feeding. Dehydration of resting eggs, after ultraviolet irradiation, to lose the hatching ability, therefore, when shelling and preservation, must avoid direct sunlight.
Prior to the shelling operation, the shelling solution was prepared. (1) Add 50 ml of a 10% sodium hypochlorite solution to 80 ml of sea water. In order to keep the pH of the solution stable, add 1.3 g of hydroxide steel to match the shelling solution required for 10 g of egg. (2) Dissolve 20% 20% calcium hypochlorite (bleach powder) in 130 ml of water, inflate for 10 minutes, add 10 grams of sodium carbonate for industrial use (or calcium oxide), then inflate for 10 minutes, and place the solution overnight. Allow it to settle and cool. The next morning, the siphon was evacuated and used for the depilation of 10 g eggs. After bleaching for a period of time, the effective chlorine content will gradually decrease. It is prepared after the actual chlorine content is measured before use. For the preparation method of shelling solution, please refer to the articles of Li Maotang, Zheng Yan, et al.
The method of shelling is to put dry eggs into sea water or tap water with a salinity of 35 ‰ and a water temperature of 25 ,C. The container can be used as a funnel-shaped cylinder sink, and continuous air ventilation from the bottom to keep the eggs suspended and fully absorb water for 1-2 hours. After that, the eggs were spherical and the excess water was drained with a 125 μm mesh screen. The absorbed eggs were placed in a 0-4°C freezer for several hours or overnight. The hypochlorite shelling solution is then added. Keep 15-20°C lower temperature during processing. In particular when processing 500 g or more dormant eggs, the water temperature of the suspension should be regularly measured. The water temperature should be kept below 40°C so as not to affect the viability of dormant eggs. Tap water or ice can be used to cool down when necessary. During the treatment, it was inflated and agitated. The shell dissolved completely after 7-10 minutes, and the egg changed from dark brown to grayish white and finally to orange. After microscopy or seeing no change in color, and no longer rising in temperature, immediately move to a 120-micron nylon screen and rinse with filtered seawater or tap water until chlorine smells. Then place in a container of seawater or tap water (5-10 ml of water per gram of egg). Add 1-2% of sodium thiosulfate or 1-2% of sodium sulfite to dechlorinate, or immerse 2-3 times in 0.1N hydrochloric acid solution (3,7% concentrated hydrochloric acid, 8.2 ml plus 91.8 ml of distilled water). This dechlorination operation must be completed within 30 seconds. Finally, it should be rinsed with water. After processing, the shelled eggs should sink, the broken eggs, and the shelled eggs float. This can be removed from the water and left for processing. The eggs can be directly used for feeding fish and shrimp, and can also be stored in a refrigerator at -4°C or dehydrated and then placed in saturated saline for use. The shelled eggs were incubated with the hatched nauplii and had the same bait spatula. The unfavorable condition is that when the eggshell is removed, it cannot float, and it settles down quickly in the water. Therefore, it must be inflated after feeding to enable the shelled eggs to be suspended in water for easy feeding. Dehydration of resting eggs, after ultraviolet irradiation, to lose the hatching ability, therefore, when shelling and preservation, must avoid direct sunlight.