| Project/Area Number |
14340267
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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 |
系統・分類
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| Research Institution | Shizuoka University |
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Principal Investigator |
TSUKAGOSHI Akira Shizuoka University, Faculty of Sciences, Assistant Professor, 理学部, 助教授 (90212050)
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| Co-Investigator(Kenkyū-buntansha) |
TAHNAKA Shigeyasu Shizuoka University, Faculty of Science, Professor, 理学部, 教授 (90146233)
TABUKI Ryouichi University of the Ryukyus, Faculty of Education, Professor, 教育学部, 教授 (60155231)
KAMIYA Takahiro Kanazawa University, Faculty of Science, Professor, 理学部, 教授 (09554024)
UBUKATA Takao Shizuoka University, Faculty of Science, Assistant Professor, 理学部, 助教授 (00293598)
SUZUKI Yutaro Shizuoka University, Faculty of Science, Assistant, 理学部, 助手 (50345807)
神谷 隆宏 金沢大学, 理学部, 教授 (80194976)
池谷 仙之 静岡大学, 理学部, 教授 (50022223)
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| Project Period (FY) |
2002 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥14,700,000 (Direct Cost: ¥14,700,000)
Fiscal Year 2005: ¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 2004: ¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 2003: ¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 2002: ¥6,100,000 (Direct Cost: ¥6,100,000)
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| Keywords | Ostracoda / Crustacea / living fossil / evolution / body segment / Taxonomy / diversity / relict species / 祖先形質 / 原始性 / 分類 |
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| Research Abstract |
A new species of genus Keijcyoidea with some plesiomorphic characters such as simple hingement, biramous antenna, clear body segments of urosom, was described as Keijcyodea infralittoralis Tsukagoshi, Okada and Horne, 2006. And its ecological nature (habitat and behavior) was also showed. Furthermore, all appendages and carapaces of all instars through the ontogeny were completely illustrated and described in the first time in Platycopida. The seventh limb which is lacking in adult was observed in younger juvenile. Therefore the lacking of the seventh limb is an autapomorphic character and the existence in younger instar suggests that Platycopida and Podocopida share a common ancestor. Though the appendage additional pattern is largely different from the Podocopida, it is suggested that the difference comes from the habitat and behavior in coarse sand sediments rather than the phylogenetical reason.
It is well known that common ostracods use the apical point of mandible for opening the both valves. But the platycopan ostracods including Keijcyodea infralittoralis do not so develop the point of mandible. After detail observations, the two new facts were regarded, i.e. : 1)the furcral point of inner carapace surface, which corresponds to the apical point, sifts to anterior side in platycopans ; 2)the anterior sifted furcral point corresponds to the humb-like process in the basal part of antenna in Platycopida. These facts mean that the platycopans do not use the mandible but the antenna for valve opening. The difference is also supported by the observation of muscle network system. The method for valve opening must come from the evolution of eating habit.
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