| Project/Area Number |
16370042
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Biodiversity/Systematics
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| Research Institution | The University of Tokyo |
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Principal Investigator |
UESHIMA Rei The University of Tokyo, Graduate school of science, Associate professor (20241771)
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| Co-Investigator(Kenkyū-buntansha) |
TSURUSAKI Nobuo The University of Tokyo, Faculty of Regional Sciences, Tottori University Professor (00183872)
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| Project Period (FY) |
2004 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥16,270,000 (Direct Cost: ¥15,400,000、Indirect Cost: ¥870,000)
Fiscal Year 2007: ¥3,770,000 (Direct Cost: ¥2,900,000、Indirect Cost: ¥870,000)
Fiscal Year 2006: ¥2,900,000 (Direct Cost: ¥2,900,000)
Fiscal Year 2005: ¥2,900,000 (Direct Cost: ¥2,900,000)
Fiscal Year 2004: ¥6,700,000 (Direct Cost: ¥6,700,000)
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| Keywords | biogeography / systematics / molecular phylogeny / species diversity / conservation / 陸産貝類 / 分類 / 軟体動物 / 分子系統解析 / 琉球列島 |
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| Research Abstract |
Ryukyu islands, an archipelago comprised of more than 100 islands between Kyusyu and Taiwan, show the highest species diversity in Japan. Terrestrial fauna of Ryukyu islands is characterized by a high level of endemism. Repeated land-bridge formation and fluctuation of sea-level during the Pliocene and Pleistocene must have enhanced the diversification of endemic fauna in Ryukyu islands. In this study, I examined molecular phylogeographic patterns of various terrestrial invertebrates focusing on land snails. Results of the molecular phylogenetic analyses demonstrated the occurrence of many cryptic species : Land snail species which was regarded as a widely distributed species in the current taxonomy are actually shown to be a complex comprised of 8-11 distinct species endemic to a narrow area. Most of these cryptic species are highly endemic and some are only known from a few localities. They are endangered species and special attention for the conservation is urgently needed. Molecular phylogeographies of 10 different families of land snails and insects are not necessarily concordant with paleogeography of Ryukyu islands. Many taxa endemic to an island, including newly discovered cryptic species, are shown to be relict species derived from ancestors with wide distribution. Further, the result of the study support an over sea dispersal and recent artificial introduction in some land snail populations. Evolutionary histories of terrestrial invertebrates in Ryukyu islands are complex and the pattern of diversification and dispersal differ among taxonomic lineages.
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