Preliminary Study on Selective Breeding of Large Yellow Croaker
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December 20 06:14:33, 2018
In view of the severe degradation of long-term inbreeding in our province's Guanjingyang yellow croaker due to its appearance, body shape, and growth traits, the large yellow croaker was developed shortly afterwards, and its body color, body type, and cold resistance were greater than Guan Jingyang’s. Yellow croaker has an advantage. Combining the actual production, the Zhejiang Aquatic Products Introduction and Breeding Center took the lead in carrying out the preliminary research on the selective breeding technology of the large yellow croaker in the ocean in Zhoushan Huaxing Base. Formulate the following breeding goals: strong vitality, golden body color, fast growth, and large individuals. The breeding method used was collective selection. Since 2003, a certain number of female and male fish that meet the selection target have been selected from the group of large yellow croakers in the ocean, and a certain number of offspring have been produced through the breeding group, and cultured in ponds to fry, fingerlings, and broodstock In the above development stage, individuals are selected according to the target family of breeding, leaving a certain number of excellent individuals. At the end of March 2004, 56 wild brooders were screened out from 300 wild large yellow croakers that had been raised in winter to undergo gonad maturation. In early April, a small amount of eggs were laid and artificial oxytocin production was performed. On April 5, 2 million fertilized eggs were obtained. After hatching, the hatchery was selected and hatched with 1.4 million fishes, which was then placed in a nursery pond for cultivation. After 30 days of management, approximately 1 million fry of a 3 cm full-length fry were obtained. The maternal spawning rate was 60%, the fertilization rate was 80%, the hatching rate was 70%, and the breeding rate was as high as 71%. 1 million large yellow croaker on May 20, using the opportunity to turn over from the box to select 20,000 strong vitality, good body color, fast growth, individual large seed stocks in specialized cages for breeding seed selection, selection rate It is 2%. At the same time randomly take 20,000 fry stocked in the adjacent cage as a control group. The rest of the fry vessels are transported to the base of six horizontal cages and cultivated to 6-7 cm large-sized fingerlings, ready for sale or release. On July 25th, the second screening for large yellow croaker was conducted according to the actual conditions such as water temperature and density. From the 20,000 tails, 2000 selections were continued, the selection rate was 10%; at the same time, for the convenience of management, 2000 pigs were randomly selected from the control group. As a comparison. The rest are reserved for his use. On October 10th, due to the increase in individuals and high density, the third screening was conducted. From the culturing of 2000 tails, 500 large yellow croakers were selected, and the selection rate was 25%. The control group also randomly selected 500 and continued to be the control of the breeding group. Daily management includes brush netting, water changing, feeding and so on. In the hot season, artificial oxygenation is required, baits are periodically fed, and the containers are periodically emptied. After the water temperature is lowered in early December, the water is admitted to the room and the daily management includes changing water, feeding bait, turning the pool, and sucking the dirt. During the month, body length and weight were measured and related data were recorded. After seven months of feeding, the results showed that when the culture conditions were basically the same, in the fry-fish breeding stage, the broiler breeding group grew 10.9% faster than the unselected breeding group, and gained weight. 20.9% faster. Breeding large yellow croaker is strong and vulnerable; it is golden in color and popular with the masses.