1. Hatching rate In general, the larvae Artemia hatching rate of 90% or more for the A-level. More than 70% for the C level.
2. The number of Artemia per gram of the number of imported Artemia per gram of the number of grams, A-level is generally 271,000 to 29,000, C-level of about 230,000. Such as high moisture content and impurities, the corresponding reduction in the number of grams per gram.
3. Moisture content
The water content of imported Artemia is 6% 7% and C is 7.3%. The annual moisture content of domestic fry Artemia is large.
1.4 impurity content
Imports of fecundity Artemia in the impurity content is generally about 0.3% o, while the domestic harvest Artemia, the amount of impurities in the upper and lower range is also larger.
2 quality identification method
Random sampling and mix well, take 100 for 1, a total of 6 copies, were placed in the culture dish; b in the culture dish into 18%. Of the salt water lOO m 1, a little stirring, so that the Artemia of the Artemia to the bottom of the water and evenly distributed in the bottom of the dish-c_ the culture dish into the incubator, and the temperature constant at 3O; d. Heating 18 hours to 24 hours, every 1 hour to check the incubation of a harvest Artemia, the hatching of the larvae sucked out with a straw and make a record; e. The total number of hatchlings will be multiplied by 6OO and multiplied by 100%, which is the percentage of hatching for this year.
2.2 random sampling, take a small amount of Artemia were evenly placed on the glass slide with a microscope: fit. Generally good harvest Artemia like tattoo table tennis, such as round for the wet Artemia or empty Artemia. To observe the attachment of Artemia outside the shell, with or without crystalline substances, in general, good quality Artemia outside the egg shell of the crystalline material or other impurities with little or no. Such as crystalline material or impurities, compared with inferior Artemia. Crystal and impurities, indicating that the Artemia did not clean up after the cleaning or precipitation treatment; c. Observe the egg breakage rate, the egg breakage rate and the egg is inversely proportional to the higher the rate of damage, the lower the egg. The average broken rate of fresh Artemia is very low, and Chen egg damage rate is higher. D. Observe the diameter of the egg, the egg diameter is small, the size of the same, the egg is better; if the size of different sizes, compared with untreated fresh Artemia.
3 comprehensive identification
Scale the amount of harvest Artemia dry by conventional hatching, hatch out of the abundance of insects to remove Artemia and impurities after weighing (wet weight leaching to not dripping), the weight divided by the weight of the young worms, the general good quality of the Artemia The weight ratio of 2.5 or more poor harvest Artemia in 1.5 or so.
4 incubation time determination
In the process of hatching of the Artemia, the hatching time of the larvae was observed. The hatching time of the larvae was l8-20 hours. The shorter the incubation time, the better the Artemia were. Such as hatching time more than 24 hours. Generally for the next year Chen Artemia, the longer the incubation time, the worse the quality of the egg.
5 bacteria detected
After the hatchlings were incubated, they were placed on a frontal tablet and dropped with a drop of water. The coverslips were covered and the insects were cut (640 x). The amount of bacteria in the larvae was examined. If a small amount of bacteria is normal, such as the body has a large number of bacteria, it should not be used.