A method for efficiently producing Nile tilapia high reproductive rate yy transformed female fish

Abstract

The invention relates to a method for efficiently producing YY transformed females of Nile tilapia with a high reproductive rate. Firstly, the XY transformed females are mated with XY males or YY super males, and the offspring are simultaneously fertilized 5 days after fertilization. Soak in estrogen and androgen synthase inhibitors until 10 days after insemination; then feed high-dose hormone-supplemented feed for feminization for 3 months after juveniles open, and use Y chromosome-specific molecular markers to screen out sex chromosomes The transformed female fish with genotype YY were fed with normal feed until 6 months old; then at the age of 6-7 months, the YY transformed female fish were treated with low-dose hormone-supplemented feed, and were raised normally until sexual maturity; finally, the fertile YY transformed female fish were screened out . Fertile YY transformed females are mated with YY super males to establish YY maintenance lines and realize large-scale production of genetic all-male fry, which can significantly increase aquaculture production, reduce aquaculture costs, and reduce the use of hormones. In areas where tilapias invade and flood A large number of YY super male fish can be released for biological control.

Description

technical field [0001] The invention belongs to the technical field of tilapia culture, and relates to a method for efficiently producing YY transformed females of Nile tilapia with high reproduction rate. Background technique [0002] Tilapia, also known as African crucian carp, is native to the brackish waters of the African continent, the Middle East and the Atlantic coast. It belongs to the cichlid family of the bony fish class Perciformes. It has the advantages of low requirements, low oxygen tolerance, strong adaptability and disease resistance; it is one of the important aquaculture species recommended by the Food and Agriculture Organization of the United Nations. In recent decades, as countries around the world have successively introduced tilapia, it has become the main species of farmed fish in the world. At present, the cultured species of tilapia include Nile tilapia, Mozambique tilapia, Olia tilapia, etc. Nile tilapia has become the main cultured species of ti...

AI Technical Summary

Problems solved by technology

[0004] 1. The method of sex reversal, that is, using male hormones to treat fry to obtain all male fish. This method is simple and easy to implement, and is widely used in farms. However, hormones are harmful to the human immune system and destroy the ecological environment of the breeding waters. Meet the requirements of pollution-free and healthy breeding;

[0005] 2. Interspecific hybridization methods, such as Nile tilapia ♀ × Olia tilapia ♂, this method is pollution-free, and the performance of commercial fish is good, but the parents need to be very pure, and the male rate is generally only 90-95%. There are still a considerable number of female fish, and there is still a certain degree of hybridization barriers, the reproductive cycle is long, and the number of seedlings is relatively small;

[0008] The applicant’s previous patent CN103409420A mentioned that estrogen was used to induce YY transformation of female fish, but it was difficult to induce YY super male fish to undergo sexual transformation only with estrogen in the early stage of embryonic development, and the sexual transformation rate was very low

In addition, the YY transformed females obtained by this method are very low in fertility or even sterile, and cannot be mass-produced

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