This standard specifies the main developmental morphological characteristics of fertilized and unfertilized eggs of black carp, grass carp, silver carp and bighead carp determined by live observation, as well as the sampling time, sampling quantity and calculation method of fertilization rate. This standard is applicable to the statistics of fertilization rate of fish eggs in artificial propagation of black carp, grass carp, silver carp and bighead carp. It can also be used as a reference for the calculation of fertilization rate of eggs in artificial propagation of other fish that lay drifting eggs. GB/T 15806-1995 Calculation method of fertilization rate of eggs of black carp, grass carp, silver carp and bighead carp GB/T15806-1995 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
The methods for calculating fertility rate of eggs ofblack carp,grass carp,silver carp and bighead carp1 Subject content and scope of application
GB/T 15806--1995
This standard specifies the main developmental morphological characteristics of fertilized and unfertilized eggs of black carp (Mylopharyngodon piceus Richardson), grass carp (Ctenopharyngodon idellus Cuvier et Valenciennes), silver carp (Hypophthalmichthys molitrir Cuvier et Valenciennes), (Aristichthys nobilis Richardson) determined by live observation, as well as the sampling time, sampling quantity and calculation method of fertilization rate.
This standard is applicable to the statistics of fertilization rate of fish eggs in artificial propagation of black carp, grass carp, silver carp and bighead carp. The calculation of egg fertilization rate in artificial breeding of other fishes that lay drifting eggs can also be used as a reference. 2 Basic terms
2. 1 Fertilized egg
Mature sperm passes through the fertilization hole of the mature egg and enters the ovum. After the egg is excited and trimmed, the male and female pronuclei fuse to form a new living cell (zygote).
2.2 Fertilization ratewwW.bzxz.Net
When the embryo develops to the high blastocyst stage, the number of normally developed fertilized eggs accounts for the percentage of the total number of eggs involved in fertilization. 3 Developmental morphological characteristics of fertilized eggs and unfertilized eggs 3.1 Fertilized eggs
3.1.1 Normal eggs After fertilization, the egg membrane absorbs water and expands rapidly, and the peri-ovum cavity expands. Under the condition of water temperature of 19~~28℃, after 1.5~2.5h, the diameter of the egg membrane increases from 1.2~2.0mm at the time of production to 4.5~6.5mm. 3.1.2 The embryonic disc is bulging, the animal pole cleavage is normal, the cleavage furrow is neat, the blastomeres are arranged regularly, and the size is uniform. 3.1.3 The ovum is elastic, the appearance is crystal clear, the egg membrane is translucent, and the outlines of the embryonic disc and ooplasm are clear. 3.2 Unfertilized eggs
Unfertilized eggs can develop briefly after water agitation, but it is difficult to develop to the high blastocyst stage. 3.2.1 The egg membrane absorbs water and expands more slowly than the fertilized egg, and the expansion degree is small. 3.2.2 The embryonic disc bulges 4 to 8 minutes slower than the normal fertilized egg, the division is irregular, the number of blastomeres is unequal, the size is different, the arrangement is irregular, the division speed is slow, there is a false high blastocyst appearance, and there is no real blastocyst structure. 3.2.3 The ovum is flat and collapsed, with poor elasticity, the egg color is dark, the egg membrane is opaque, and the embryonic disc and ooplasm are not very transparent. After the false high blastocyst bulges, the ovum begins to become gray and turbid.
4 Calculation method of fertilization rate
4.1 Sampling time
Approved by the State Administration of Technical Supervision on December 8, 1995 and implemented on July 1, 1996
GB/T 15806-1995
Sampling shall be conducted when the fertilized egg develops to the high blastocyst stage. When the water temperature is 22-28℃, it is appropriate to sample 2.0-3.5 hours after fertilization. At this time, fertilized eggs and unfertilized eggs are very easy to distinguish. 4.2 Sampling quantity and calculation method
Randomly take 100-200 eggs from the incubation ring or other types of incubation containers, put them in the culture, observe them with the help of various magnifying glasses, and correctly identify whether they are fertilized or not according to the provisions of Chapter 3. Repeat the sampling twice, calculate the average value, and calculate the percentage of fertilized eggs to the number of sampled eggs. The calculation formula is as follows:
Where: R——fertilization rate,%;
X,—number of fertilized eggs
ZX——total number of sampled eggs.
4.3 Once the fertilization rate is determined, it should be immediately filled in the hatching record as a basis for calculating the emergence rate. Additional remarks:
This standard is proposed by the Ministry of Agriculture of the People's Republic of China. This standard is under the jurisdiction of the Yangtze River Fisheries Research Institute of the Chinese Academy of Fishery Sciences. This standard was drafted by the Department of Fisheries of Huazhong Agricultural University. The main drafter of this standard is Cao Keju.
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