First, it is best to select the broodstock before the Spring Festival (ie when a large number of adult fishes are harvested). The best temperature is 4°C to 10°C when the adult fish are harvested. At this time, the food intake of the fish is reduced, the activity is slow, and the scales are tight and not easily injured.
Second, age
Selected broodstock should reach or approach sexual maturity. In the south, the light intensity is strong, the accumulated temperature of water is high, and the fish eat a long time, and the quantity is large. The four major fishes generally mature 1 to 2 years earlier than the northern ones. The age of sexual maturity is generally: herring 5th to 7th in age; grass carp and calyx 3rd to 5th instar; male fish generally mature one year earlier than female fish.
Third, weight
Individuals of the same species are generally heavier and heavier, the greater the amount of eggs they spawn, and the greater the number of eggs laid. Therefore, when selecting broodstock, the same age should be selected as large and heavy fish as possible. The individual weight of the selected broodstock is generally required: more than 6 kilograms of herring, more than 8 kilograms of flowers, and 3 kilograms of white peony. Males can be slightly lighter than females.
Fourth, constitution
Request to choose a healthy body, scales, fins intact, no traumatic, disease-free fish as broodstock.
Fifth, female and male ratio
Selecting broodstock fish generally has slightly more fish tails than female fish to facilitate full fertilization of fish eggs. The ratio of female to male is generally 1:1.2.
Six, gonadal development
Selected broodstock, gonads (ovary or testis) development requirements to reach the third period. Two methods can be used to observe: firstly from the appearance, there are obvious ovary bulges on both sides of the abdomen on the gonads that reach the third stage of gonad development; secondly, there are several representative representative anatomies of the fish that are self-supported, and the gonadal development reaches the third During the period of broodstock, the ovary grows on both sides of the abdomen and is grayish blue. In the winter, the ovary is 2 cm wide and 15 cm long.
VII. Kinship
If mating with the offspring of the offspring of the same broodstock, their offspring will have undesirable traits, resulting in slow growth and disease, and reduced yield. Therefore, the female and male fish used for breeding broodstock should come from different places, and the distance between the two places should be as far as possible.
Eight, transportation methods
Short distance: Nylon bag is used for shipment. Wash the nylon bag first and put it in the pool water. Then put the broodstock into it. One end of each bag. The head of the fish is towards the mouth of the bag. It is easy to breathe, and it is immediately transported and stocked in the pool. Long-distance transport: transport by truck or ship, and use big fish larvae when transporting, usually bamboo, with water capacity of 0.4 cubic meters, and 35 kg to 60 kg of broodstock per cage. In the course of transportation, the broodstock in the surimi should be prevented from lacking oxygen. If oxygen deficiency is found, new water or artificial oxygen should be replaced in time to avoid death of broodstock.
Nine, matters needing attention
1. The best time to catch and transport broodstock is at night. 2. Intensive adult fish, to reduce feeding before catching, to prevent fish from jumping after eating and causing death and injury. 3. Choose a broodstock that lives in a large body of water, because of the large body of water, good environmental conditions, robust fish, strong disease resistance, and good genetic traits. 4. During the operation, if the broodstock collides with the scales and the rays are broken, the wound can be dried with a clean cloth first, apply 3% to 4% of salt water, and then coat a layer of Vaseline or butter to prevent the infection of water mold. disease.
Second, age
Selected broodstock should reach or approach sexual maturity. In the south, the light intensity is strong, the accumulated temperature of water is high, and the fish eat a long time, and the quantity is large. The four major fishes generally mature 1 to 2 years earlier than the northern ones. The age of sexual maturity is generally: herring 5th to 7th in age; grass carp and calyx 3rd to 5th instar; male fish generally mature one year earlier than female fish.
Third, weight
Individuals of the same species are generally heavier and heavier, the greater the amount of eggs they spawn, and the greater the number of eggs laid. Therefore, when selecting broodstock, the same age should be selected as large and heavy fish as possible. The individual weight of the selected broodstock is generally required: more than 6 kilograms of herring, more than 8 kilograms of flowers, and 3 kilograms of white peony. Males can be slightly lighter than females.
Fourth, constitution
Request to choose a healthy body, scales, fins intact, no traumatic, disease-free fish as broodstock.
Fifth, female and male ratio
Selecting broodstock fish generally has slightly more fish tails than female fish to facilitate full fertilization of fish eggs. The ratio of female to male is generally 1:1.2.
Six, gonadal development
Selected broodstock, gonads (ovary or testis) development requirements to reach the third period. Two methods can be used to observe: firstly from the appearance, there are obvious ovary bulges on both sides of the abdomen on the gonads that reach the third stage of gonad development; secondly, there are several representative representative anatomies of the fish that are self-supported, and the gonadal development reaches the third During the period of broodstock, the ovary grows on both sides of the abdomen and is grayish blue. In the winter, the ovary is 2 cm wide and 15 cm long.
VII. Kinship
If mating with the offspring of the offspring of the same broodstock, their offspring will have undesirable traits, resulting in slow growth and disease, and reduced yield. Therefore, the female and male fish used for breeding broodstock should come from different places, and the distance between the two places should be as far as possible.
Eight, transportation methods
Short distance: Nylon bag is used for shipment. Wash the nylon bag first and put it in the pool water. Then put the broodstock into it. One end of each bag. The head of the fish is towards the mouth of the bag. It is easy to breathe, and it is immediately transported and stocked in the pool. Long-distance transport: transport by truck or ship, and use big fish larvae when transporting, usually bamboo, with water capacity of 0.4 cubic meters, and 35 kg to 60 kg of broodstock per cage. In the course of transportation, the broodstock in the surimi should be prevented from lacking oxygen. If oxygen deficiency is found, new water or artificial oxygen should be replaced in time to avoid death of broodstock.
Nine, matters needing attention
1. The best time to catch and transport broodstock is at night. 2. Intensive adult fish, to reduce feeding before catching, to prevent fish from jumping after eating and causing death and injury. 3. Choose a broodstock that lives in a large body of water, because of the large body of water, good environmental conditions, robust fish, strong disease resistance, and good genetic traits. 4. During the operation, if the broodstock collides with the scales and the rays are broken, the wound can be dried with a clean cloth first, apply 3% to 4% of salt water, and then coat a layer of Vaseline or butter to prevent the infection of water mold. disease.