| Project/Area Number |
04806025
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
General fisheries
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| Research Institution | HIROSHIMA UNIVERSITY |
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Principal Investigator |
YAMAMOTO Tamiji Hiroshima University Faculty of Applied Biological Science Assistant Professor, 生物生産学部, 講師 (40240105)
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| Co-Investigator(Kenkyū-buntansha) |
MATSUDA Osamu Hiroshima University Faculty of Applied Biological Science Professor, 生物生産学部, 教授 (60034469)
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| Project Period (FY) |
1992 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1993: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1992: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | Alexand rium / Continuous culture / Phosphorus / Mikawa Bay / Semi-contimuous culture / 広島湾 |
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| Research Abstract |
Achievement of continuous culture of Alexandrium tamarense was unsuccessful due to the inherent property attaching to the wall of the clture vessel in the mixing water. Therefore, we ompoloyed both batch culture and semi-continuous culture methods insterad. The experimental results obtained in this study were as follows. (1) Optimum temperature and salinity for the growth were 15 ﾟC and 32-35%. (2) Maximum specific growth rate was 0.26d^<-1> using screw-capped test tube, and 0.48d^<-1> using 1l flusk, shich obviously showed the wall effect of the vessel. (3) the threshols light intensity for the growth was 30muE m^<-2> s^<-1> , which means A.tamatense could never grow below the light level. (4) Light-and-dark experiment revealed that A.tamarense takes up phosphate in the light period and grow in the dark period. (5) Minimum phosphorus cell quota of A.tamarense was 0.56pmol cell^<-1> . (6) Miaximum specific uptake rate and half saturation constant for phosphate were 1.59h^<-1> and 1.85muM.(7) Similar experiments were carried out for a diatom Skeletonema costatum. The comparison of phosphate uptake kinetic parameters and growth parameters between them suggested that A.tamarense could not prevail over S.costatum in natural environment, hence disappearance of coexisting in the water column by some other reasons would be necessary gor propagation of A.tamarensw.
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