| Project/Area Number |
15253008
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 海外学術 |
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| Research Field |
Stratigraphy/Paleontology
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| Research Institution | National Museum of Nature and Science, Tokyo |
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Principal Investigator |
KASE Tomoki National Museum of Nature and Science, Tokyo, Geology, Curator in chief (20124183)
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| Co-Investigator(Kenkyū-buntansha) |
KITAMURA Akihisa Shizuoka University, Faculty of Science, Associate Professor (20260581)
SUZUKI Yutaro Shizuoka University, Faculty of Science, Assistant (50345807)
KANO Yasunori Miyazaki University, Faculty of Agriculture, Assistant (20381056)
TABUKI Ryoichi Ryukyu University, Faculty of Education, Professor (60155231)
CHIBA Satoshi Tohoku University, Graduate School of Science, Associate Profeffor (10236812)
酒井 英男 富山大学, 理学部, 教授 (30134993)
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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 |
¥33,930,000 (Direct Cost: ¥26,100,000、Indirect Cost: ¥7,830,000)
Fiscal Year 2005: ¥7,670,000 (Direct Cost: ¥5,900,000、Indirect Cost: ¥1,770,000)
Fiscal Year 2004: ¥11,310,000 (Direct Cost: ¥8,700,000、Indirect Cost: ¥2,610,000)
Fiscal Year 2003: ¥14,950,000 (Direct Cost: ¥11,500,000、Indirect Cost: ¥3,450,000)
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| Keywords | submarine cave / Indo Pacific / speciation / Mollusca / biogeography / evolution / paleoenvironment / early development / コハクカノコ科 / 初期発生 / 捕食 / 間隙水環境 / アンキアリン環境 / 巻貝 / アマオブネガイ目 / 甲殻類 / タマガイ科 / 陸上進出 |
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| Research Abstract |
1. We systematically described two new species of mysid crustaceans and one new genus and three new species of neritilid gastropods.
2. A unique ecological feature in submarine caves is the infrequency of predator animals, reminiscent of the mid-Mesozoic shallow marine ecosystem. To compare the ecological features between the modern submarine caves and mid-Mesozoic shallow marine ecosystem, we studied the history of shell-drilling, predatory naticid gastropods as they represent the best fossil records of predator-prey relationship. We showed that naticids first appeared in the end of Cretaceous and started drilling predation since that time. On the other hand, we examined drilling and crushing predation in shells of two submarine caves of Okinawa, southern Japan as low as 5%, the frequency is equivalent to those for the late Cretaceous shallow marine assemblages. This is the first documentation of predatory activity in submarine caves.
3. Neritilia cavernicala n. sp. was described from anchialine caves of two islands separated more than 200km apart in the Philippines. We presented the first genetic structure for anchailine cave organisms (mitochondrial cytochrome oxidase I), which shows no evidence of genetic isolation between the islands. All individuals are part of a panmictic population and their seemingly isolated cave habitats do not limit gene flow in this species. Larval dispersal may be widely applicable to anchialine stygobites with insular distributions.
4. A taxonomic study of Nerilitidae shows the species diversity is the highest in SE Asian islands and becomes smaller in accordance with the distance from the diversity center. Contrast to the previous, widely accepted view that cavericolous animals dispersed primarily by plate tectonics and vicariance, transoceanic dispersal should have played an important role, like most modern invertebrates in tropical coral-reef seas, in forming the present distribution of the cavericolous neritilids.
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