1998 Fiscal Year Final Research Report Summary
Promotion of multi-species coexistence in the community on microatolls of massive coral Porites : a test of Inhabitation-chain hypothesis
| Project/Area Number |
08640795
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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 |
生態
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| Research Institution | Tohoku University |
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Principal Investigator |
NISHIHIRA Moritaka Biological Institute, Graduate School of Science, Tohoku University Professor, 大学院・理学研究科, 教授 (80004357)
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| Project Period (FY) |
1996 – 1998
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| Keywords | Inhabitation-chain / Species diversity / Multi-species coexistence / Microatoll / Fish community / Enjoyableness / Predation defense / Bleaching |
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| Research Abstract |
Mechanisms by which multi-species coexistence is maintained and promoted were studied for the communities developed on microatolls of massive coral Porites in the moat of Kudaka Island, Okinawa for 1996 to 1998. It was proved that with growth of the microatoll, the area of the top was not only enlarged but also became more irregular due to bioerosion by boring bivalves such as Tridacna or grazing by urchins such as Echinometra. According to the inhabitation of various sessile organisms including algae, corals, vermetids etc., species richness of the community increased. Provision, creation and conditioning of microhabitat by various organisms seemed to induce new species to colonize, thus promoted multispecies coexistence. Dendropoma, a vermatid buried in the coral skeleton make the coral surface smooth, which make the coral difficult to be grazed by parrot fish. This relation between vermetids and host coral seemed to have been strengthened coevolutionarily under the presence of strong predators. In the summer of 1998 , coral bleaching episode was recognized in the moat of Kudaka Island, but those massive corals which were partially bleached all recovered in a half year.
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