| Project/Area Number |
15580172
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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 | Kitasato University |
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Principal Investigator |
HAYASHIZAKI Ken-ichi Kitasato university, School of fisheries sciences, Assistant professor, 水産学部, 講師 (80208636)
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| Co-Investigator(Kenkyū-buntansha) |
ASAHIDA Takashi Kitasato university, School of fisheries sciences, Associate professor, 水産学部, 助教授 (00296427)
SAITOH Kenji Tohoku national fisheries research institute, Resources Enhancement Section, Head of the section, 東北区水産研究所, 室長 (80371798)
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| Project Period (FY) |
2003 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥2,700,000 (Direct Cost: ¥2,700,000)
Fiscal Year 2005: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2004: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2003: ¥1,100,000 (Direct Cost: ¥1,100,000)
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| Keywords | chum salmon / mitochondrial DNA / microsatellite DNA / scale / growth analysis / density dependent effect / hatchery population / genetic diversity / mtDNA |
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| Research Abstract |
To reevaluate artificial propagation program in Japan genetic and ecological analysis were conducted utilizing fish scale archives. Firstly a complete sequence of mitochondrial gene was determined for chum salmon. To find polymorphic sites in protein coding regions on DNA sequences samples from remotely distanced populations are compared. Sequences of about 1000 by in ND2 region on mitochondrial gene were determined. Three polymorphic sites were found in about 200 bp length with that region. As for microsatellite DNA 6 loci were investigated, and high length variation was observed on Oke3 locus. Genetic diversity was highest in Iwate population, followed by Ibaraki population and lowest in Alaska population. The amount and PCR amplification of extracted DNA from archived fish scales were compared among the durations of time for preservation. For 2 years preservation we yield enough amount of DNA with good qualities. From samples older than 10 up to 30 years degraded but comparable amount of DNA to 2 years preservation samples was extracted. Size decrease of chum salmon returned to Iwate prefecture in 1980s was explained by stunted growth at first and a year before return, which is a result of density dependent effect. On the other hand during recent low return rate period, size at return was recovered comparable to that in early 1980s. The correlation analysis between return rate and environmental factors such as water temperature near shore did not necessarily show significant relationships. To validate the age determination method using fish scales we tried otolith observation. Some otoliths have dark inner part, which disturbed the clear view of first year rings. We did not get any proof to deny the accuracy of scale age determination. We measured carbon, nitrogen and sulfur isotope ratios using chum scales. Except for sulfur each isotope value had own pattern of annual fluctuation.
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