The ecological conditions of hatching of Artemia eggs are important factors affecting hatchability of Artemia eggs. The Artemia eggs of the better quality, if the hatching conditions are not properly controlled, the hatching rate will become very low. In China, the main criteria for controlling the current incubation conditions are as follows: Salinity: normal seawater, artificial seawater, or salinity formulated with coarse salt is preferably 20-30%. When the temperature is appropriate, salinity is properly increased and the hatching rate will be increased. The increase is generally at the highest hatching rate of 60-70%; however, when the salinity reaches 90%, the eggs do not absorb water and cannot hatch. PH: Generally best between 8-9; in production, high-density incubation plus NAHCO3 is used to neutralize the produced CO2. Generally, 1-2 grams of NAHCO3 per liter of seawater can stabilize the pH of seawater. Temperature: When the water temperature is between -18°-4° or 32-40°, embryos of Artemia eggs do not die, but do not hatch; when the water temperature is between 4-32°C, it increases with temperature. High, metabolic enhancement of the embryo. In the production of the incubation temperature is generally 28-30 degrees. Dissolved oxygen: In production, as long as DO>0.2ppm, it can meet the needs of Artemia. When incubating, it is generally necessary to inflate and agitate the water, and at the same time, to prevent oxygenated dead ends, thereby preventing egg accumulation and hypoxia. Illumination: Light stimulates embryonic development at the beginning of hatching and stimulates it. Eggs in different regions generally have different lighting requirements. The proper illumination of American Artemia eggs is 1000 lux and the suitable illumination of Artemia eggs in China is 1500 lux. Density: In production, the optimum density of Artemia eggs should be controlled to be less than 10g eggs/liter. In large-scale production, hatching density should be 3-5g eggs/liter. In the production, it is necessary to follow the above criteria to hatch Artemia eggs. If conditions do not meet the requirements, appropriate adjustments should be made based on the actual situation so that the economic efficiency of Artemia eggs can be optimized. At present, there are many methods to determine the hatchability of Artemia eggs in domestic and foreign countries. However, some methods lack the scientific basis and are therefore not often adopted by people. Now the more authoritative methods are as follows: 1. International common standard method, now Divided into A method and B method: A method: said 250mg Artemia eggs, placed in 100ml salinity of 35 seawater, light 1000lux (continuous), water temperature 25 degrees, and inflated. One hour later, 10 samples were taken, 0.5 ml for each sample, and about 100 Artemia eggs in water. Samples were placed on filter paper, counted and averaged C. Wash the eggs on the filter paper into a petri dish and keep the same conditions as above. The water depth is 0.3-0.5cm. Incubate under these conditions. After 48 hours, larvae were counted and averaged for N. Calculate the hatching rate: H%=100*(N/C). Method B: 250 mg Artemia eggs are placed on 100 ml seawater with a salinity of 35, and the water is irradiated with 1000 lux (continuous) at a water temperature of 25 degrees and inflated and incubated. After 48 hours, 0.5 ml, 10 samples were taken; approximately 100 nauplii and unhatched eggs per sample were in the Petri dish. Count the average number N of nauplii. Shelling agents are added, the shells are dissolved, and the unhatched eggs become shellless eggs. Count, average C. Calculate the hatching rate: H%=100*H/(N+C). 2. Density method: 1 g of Artemia eggs are placed in 1000 ml of sea water with a salinity of 35 and soaked for 2 hours. Take 1 ml sample in a Petri dish (4 parallel samples) Count the average A of eggs in each sample (empty shell and broken eggs). 1 g of Artemia eggs (approx. 1000 ml) were incubated in sea water at T=28 degrees, pH=7.5-8.5, salinity=35, and irradiated with 1000 lux of light. After 36-48 hours, 1 ml of sample was taken in a Petri dish (four parallel samples), and the average number of no-larvae B in each sample was counted. Calculate the hatching rate: H%=100*B/A. 3, weight method: Take 1 pound of eggs hatched in 10 tons of seawater, light 1000lux, continuous, T = 28 degrees. Larvae are collected after 20 or 48 hours and weighed. If the baby weighs about 950 grams, then the hatching rate of this Artemia egg is about 70%. If the young body weight is about 1250 grams, the hatching rate of this Artemia egg is about 95%.