| Project/Area Number |
61540563
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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 |
Stratigraphy/Paleontology
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
MORI Kei Associate Professor, Tohoku University, 理学部, 助教授 (00004466)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAMORI Toru Research Associate, Tohoku University, 理学部, 助手 (00192229)
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| Project Period (FY) |
1986 – 1987
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| Project Status |
Completed (Fiscal Year 1987)
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| Budget Amount *help |
¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1987: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1986: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Keywords | Scleractinian corals / Solitary / Intraspecific variation / Septa / パリ / サンゴ / 成長輪 / 日輪 |
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| Research Abstract |
Intraspecific morphological variations have been investigated based on 1090 specimens of a Pleistocene solitary scleractinian coral, Caryophyllia (premocyathus) compressa Yabe and Eguchi. Spcial attention has been paid to variations in septal arrangements, septal numbers, insertion patterns of third-cycle septa, and pali. The specimens contain nine: different septal plans from hexameral to decatetrameral, among which those having a decameral plan are the most common. There is a clear regularity in number and position of the third-cycle septa. Specimens in which the third cycle is incomplete are also considered to be mature forms. Number and position of pali are intimately related to the number and insertion pattern of the third-cycle septa. In extreme cases, there exist specimens having only two cycles of septa and lacking pali. Ninety-nine varieties in septal arrangements are considered to be present in the fossil population, although 57 have been found in the collection. The present species includes many specimens which do not show bilateral symmetry.
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