| Project/Area Number |
11660173
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
General fisheries
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
ADACHI Shinji Hokkaido Univ., Grad.School of Fish.Sci., Asso.Pro., 大学院・水産科学研究科, 助教授 (40231930)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAHA Etsuro Hokkaido Univ., Fac.of Fish., Asso.Pro., 大学院・水産科学研究科, 助教授 (60191376)
YAMAUCHI Kohei Hokkaido Univ., Grad.School of Fish.Sci., Pro., 大学院・水産科学研究科, 教授 (10109514)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2000: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1999: ¥2,100,000 (Direct Cost: ¥2,100,000)
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| Keywords | Sex determination / Sex differentiation / Environmental factor / Temperature / pH / Goldfish / Barfin flounder / Teleost |
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| Research Abstract |
1) Temperature-sensitive period
Goldfish and barfin flounder exhibited a critical temperature-sensitive period. The end of the temperature-sensitive period was just before morphological sex differentiation. Moreover, to produce masculinized XX goldfish, it was needed to be kept in high temperatures throughout the temperature-sensitive period. While in order to produce a population where the genotypic and phenotypic sex coincide, it needed that fish are reared below 23℃ during the sensitive period without exact control of constant temperature.
2) Histological changes in sex differentiation under the different rearing temperature
Masculinization of genetic female did not occur by low temperature treatment in goldfish. Ovarian differentiation was completely delayed at low temperature.
3) Effects of various environmental factors on sex determination
In goldfish, density and photoperiod have no effect on sex determination, although low pH treatment produced male-biased sex ratio while high pH treatment has no effect on masculinization. In contrast, high pH treatment led to masculinization in barfin flounder. In addition, cortisol treatment produced high male populations in goldfish, indicating a possibility of masculinization by environmental factors through stress responses.
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