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differnet ways of sex determination in fishes

PRODUCT PLANNING. differnet ways of sex determination in fishes. 1711405 徐寅. PRODUCT PLANNING.

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differnet ways of sex determination in fishes

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  1. PRODUCT PLANNING differnet ways of sex determination in fishes 1711405 徐寅

  2. PRODUCT PLANNING A sex-determination system is a biological system that determines the development of sexual characteristics in an organism. Most organisms that create their offspring using sexual reproduction have two sexes. Occasionally, there are hermaphrodites in place of one or both sexes. There are also some species that are only one sex due to parthenogenesis, the act of a female reproducing without fertilization.

  3. PRODUCT PLANNING 1）genetic system2）environmental factor 3）exogenous hormones

  4. PRODUCT PLANNING genetic system 1.xx/xy Salmonidae 鲈科鱼

  5. PRODUCT PLANNING 2.zw/zz Lateolabrax maculatus 花鲈

  6. PRODUCT PLANNING 3.常染色体型 zebrafish

  7. PRODUCT PLANNING 4.zo/zz和xx/xo Coilia brachygnathus 短颌鲚

  8. PRODUCT PLANNING 5.X1X1X2X2/X1X2Y Xiphophorus maculatus 新月鱼

  9. PRODUCT PLANNING environmental factor The living environment of fish can be divided into two categories: physical and chemical environment and social environment. Physical and chemical environmental factors include temperature, pH, light, salinity, alkalinity and so on.

  10. PRODUCT PLANNING At certain temperatures, the temperature can affect the sex determination of genes, leading to the change of fish sex.In tilapia, the higher male rate is produced at high temperature (34~37), while Mozambique tilapia can increase the proportion of male fish at low temperature (19 or 20 degrees C). Oreochromis mossambicus 莫桑比克罗非鱼 Oreochromis niloticus 尼罗罗非鱼

  11. PRODUCT PLANNING The study found that under the acidic condition, the Xiphophorus helleri 100% is developed into a male, but it produces 98% of the female under the weak alkaline condition (pH=7.8). Romer and Beisenherz also obtained similar results in black bellied flowers (Poecilia Poecilia melanogaster). Xiphophorus helleri 剑尾鱼

  12. PRODUCT PLANNING Social environment factors include group structure, sex ratio and so on.Dr. Francis found that the structure of the colony could affect the sex of the Macropodus opercualris. individuals tended to develop into males while the gregarious fish differentiated into females. Macropodus opercualris 天堂鱼

  13. PRODUCT PLANNING exogenous hormones Sex differentiation can be controlled by sex hormones before sex differentiation is about to begin and gender is not fully expressed. After sex differentiation, sex hormone can only play a role in changing the secondary sex and inhibiting the development of gonad. Biologists used estradiol to turn the genetic male's Oryzias latipes into a physiological female fish. Oryzias latipes 青鳉

  14. PRODUCT PLANNING 谢谢

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