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CN-121986754-A - Induction method, feed and application of Atlantic salmon XX-type pseudo-male fish

CN121986754ACN 121986754 ACN121986754 ACN 121986754ACN-121986754-A

Abstract

The invention relates to an induction method, feed and application of Atlantic salmon XX-type pseudo-male fish, belonging to the technical field of aquaculture breeding, wherein the method comprises the following steps: when the atlantic salmon inherited female fries are ingested in the opening, 17 alpha-methyltestosterone or letrozole is fed every day for a period of time greater than or equal to 60 days, and XX-type pseudo-androgens are obtained. The invention also provides a feed containing 17 alpha-methyltestosterone or letrozole and application of the feed in cultivation of Atlantic salmon pseudo-androgens. The invention precisely shortens the effective window period to the 60 th day after starting exogenous ingestion, the induction success rate of 17 alpha-methyltestosterone of 1.5-4.5mg/kg can reach 100%, the induction success rate of letrozole of 150mg/kg is 80%, the induction success rate of 200mg/kg is 83%, and the induction success rate of 250mg/kg is 100%.

Inventors

  • LIU YUYAN
  • SHAO CHANGWEI
  • Dong Caichao
  • WANG MENG
  • CAO XUWEN
  • ZHANG YANMING
  • WANG QIAN
  • WANG HONGYAN
  • LIU KAIQIANG

Assignees

  • 中国水产科学研究院黄海水产研究所

Dates

Publication Date
20260508
Application Date
20260212

Claims (10)

  1. 1. A method for creating Atlantic salmon pseudo-male fish is characterized by comprising the following steps of feeding 17 alpha-methyltestosterone or letrozole daily for a period of time greater than or equal to 60d when an Atlantic salmon genetic female fish fry is ingested at an opening, and obtaining XX-type pseudo-male fish.
  2. 2. The method according to claim 1, wherein 17 alpha-methyltestosterone or letrozole is mixed into feed for feeding, and the content of 17 alpha-methyltestosterone in the feed is 1.5-4.5 mg/kg.
  3. 3. The method according to claim 1, wherein 17 alpha-methyltestosterone or letrozole is mixed into the feed for feeding, and the letrozole content in the feed is 150-250 mg/kg.
  4. 4. The method of claim 1, wherein the feeding of 17α -methyltestosterone or letrozole is started 800 days at the time of opening of female atlantic salmon.
  5. 5. The method of claim 4, wherein the feeding is for a period of 60 days.
  6. 6. The method of claim 4, wherein the feeding is performed in a satiety mode.
  7. 7. A feed for creating pseudo-androgens in atlantic salmon, said feed comprising 17 α -methyltestosterone or letrozole and an atlantic salmon basal feed.
  8. 8. A method for preparing the feed according to claim 7, wherein the method comprises the steps of dissolving 17 alpha-methyltestosterone powder or letrozole with 95% ethanol by volume fraction, uniformly spraying on Atlantic salmon base feed, and uniformly mixing to attach 1.5-4.5 mg 17 alpha-methyltestosterone or 150-250 mg letrozole to each kg Atlantic salmon base feed.
  9. 9. Use of the feed of claim 7 for the preparation of Atlantic salmon pseudo-males.
  10. 10. The method according to claim 9, wherein the method comprises the steps of incubating Atlantic salmon's eye eggs at a water temperature of 6.0+ -0.5 ℃ and a pH of 7.0-8.0, raising the water temperature to 10.0+ -0.5 ℃ at a rate of not more than 0.5 ℃ per day, when the fish fry is changed from bottom aggregation to floating state, feeding the fish fry with artificial feed containing 1.5-4.5 mg of 17 alpha-methyltestosterone or 150-250 mg of letrozole and having a grain size of 0.2mm per kilogram, gradually changing to 0.3-0.4mm and 0.5-0.8mm specification feed as the fish fry grow, providing annular water flow in the culture pond to facilitate the growth of the fish fry and gradually adjusting the water temperature to 13.0+ -0.5 ℃ as the fish fry starts to swim.

Description

Induction method, feed and application of Atlantic salmon XX-type pseudo-male fish Technical Field The invention belongs to the technical field of aquaculture breeding, and particularly relates to an induction method, feed and application of Atlantic salmon XX-type pseudo-male fish. Background Atlantic salmon (Salmo salar) is a major cultivated fish worldwide, is a species representative of salmon, is delicious in meat quality and suitable for raw food, and is rich in nutrients such as Omega-3 fatty acid, vitamin D, antioxidants and the like, so that the salmon is favored in the market. Male atlantic salmon usually reaches sexual maturity (especially prematurity of second age) earlier than female, and male fish after sexual maturity grow stagnate, meat quality is soft, body color becomes black, and economic benefit is seriously affected. In contrast, the population of all-female Atlantic salmon grows fast, matures late and has regular specifications. Thus, the production of full-female offspring is a consensus of the international Atlantic salmon farming industry. The core technology for preparing the total female population is to obtain XX-type pseudo-male fish. The artificial control method of fish sex includes interspecific hybridization, artificial induction of gynogenesis (androstane) development, environmental regulation, genetic engineering, hormone induction and the like, and the advantages and disadvantages of the various methods are as follows: (1) Interspecific crossing technology, in which the offspring generated by interspecific crossing of different species are used to generate bias of sex ratio or all have single sex. By utilizing natural biological processes, external chemical or physical intervention is not needed, and in principle, only two species are required to be mixedly cultured. But the success rate of producing all-male offspring suitable for specific species combinations (such as the interspecific hybridization of certain tilapias) is lower. Heterosis is not necessarily apparent and offspring growth performance may be undesirable. (2) Artificial inducing gynogenesis (androstatic nucleus) by physical or chemical inactivation of sperm or ovum, and treating with cold shock or pressure to double chromosome to obtain offspring containing female parent or male parent genome. Can realize the production of all female or all male groups, has remarkable effect and can quickly establish a pure line. But the treatment process has great damage to embryo and high seedling malformation rate. Precise control of the timing and intensity of inactivation and chromosome doubling is required. And offspring have low genetic diversity and need strict management to prevent germplasm degeneration. (3) And the environmental factor regulation and control, namely, the gonadal differentiation is influenced by regulating and controlling the environmental conditions such as water temperature, pH, illumination, density and the like in the sex differentiation sensitive period. The method has no foreign matter, is an ideal green technology, and has low cost, and only needs to control the culture environment parameters. However, the mechanism of action is complex, precise control and prediction are difficult, the fluctuation of sex ratio is large, and 100% is difficult to achieve. The fish type is optimized according to specific fish types, and the universality is poor. (4) Genetic engineering techniques to directly create sterile or monosomic populations by knocking out or silencing sex-determining key genes (e.g., dmrt1, amh, etc.) by gene editing (e.g., CRISPR/Cas 9). Directly solves the problem from the root, and can create characters which cannot be realized by the traditional method. Once the breeding lines are successfully created, the breeding lines can be permanently used without repeated treatment. But requires a deep molecular biology foundation and expensive equipment, and there are ethical disputes and regulatory restrictions on the application in food production, and consumer acceptance of genetically engineered foods is low. (5) In the sex differentiation critical period, exogenous hormone (androgen or estrogen) is fed to induce the genetic sex to develop in opposite direction. The technology is mature and efficient, is the most classical and widely applied method, and has the sex reversal success rate higher than 95%. Is relatively simple, suitable for large-scale operation, has relatively low hormone cost, is suitable for commercial application of aquaculture, but needs to accurately grasp dosage and treatment window, otherwise is easy to fail or causes sterility. Disclosure of Invention The invention aims to provide an induction method, feed and application of Atlantic salmon XX-type pseudo-male fish. 17 alpha-methyltestosterone and letrozole can induce the XX-type genetic female fish of the Atlantic salmon to be subjected to sex reversal into XX-type pseudo-male fish, so that the induction success