| Project/Area Number |
14405008
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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 | 海外学術 |
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| Research Field |
生態
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| Research Institution | Osaka City University |
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Principal Investigator |
KOHDA Masanori Graduate School of Science, Osaka City University, Department of Biology and Geoscienoes, Professor (70192052)
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| Co-Investigator(Kenkyū-buntansha) |
NAKASHIMA Yasuhiro Nihon University, Faculty of Economy, Professor (50295383)
MUNEHARA Hiroyuki Hokkaido University, Field Science Center for Northern Biosphere, Associate Professor (80212249)
KARINO Kenji Tokyo Gakugei University, Department of Biology, Faculty of Education, 助教授 (40293005)
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| Project Period (FY) |
2002 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥12,800,000 (Direct Cost: ¥12,800,000)
Fiscal Year 2004: ¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 2003: ¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2002: ¥6,100,000 (Direct Cost: ¥6,100,000)
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| Keywords | Social evolution / Mating systern / Male reproductive tactics / Cooperative breeding / Cooparative polyandry / Female control / Reproductive success / Sexual Conflicts / 精子競争 / 雌による父性の操作 / 協同的一妻二夫 / DNA父性判定 / 雄の繁殖戦術 / カワスズメ / 巣の選択性 / 脊椎動物 / タンガニイカ湖魚類 / 繁殖戦術 / 社会行動 / 繁殖寄生 / 血縁淘汰 / 社会構造 / 繁殖戦略 / タンガニイカ湖 / カワスズメ科魚類 / 行動生態学 / 繁殖多型 |
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| Research Abstract |
In this year, Kohda and Takeyarna as a cooperator studied in Lake Tanganyika. Kohda researched breeding ecology of cooperatively polyandrous cichlid Chalinochramis brichardi, especially on the spawning sites in wedge-shaped nests. He found further examples where egg clutches were deposited at the point in the nest to which large alpha males can reach. These were similar to depositing sites observed in previous years. These results may indicate female selectively spawn eggs at the site to which large alpha males can reach, and may lead the hypothesis that through selection of spawning sites by females of this fish, they may control paternity distribution in this fish.
In laboratory experiments at the Mpulungu City, female choice of nest shape, wedge-shaped nests and wide nests was examined. AS predidted from field observation in previous years, female tended to choose wedge-shaped nests in which female can control paternity distribution. From field observation of C.brichardi, we obtained
… More
further examples of egg clutches. Of 11 egg olutches 10 were deposited at the site in nest to which a large alpha male can enter. We made a hypothesis that females can control paternity distribution by selecting such sita as spawning site. Female control of paternity distribution in cooperative breeding vertebrates has been suggested, The test of this hypothesis will be the first example of female control of paternity distribution in extra-fertilizing animals.
N.savoryi is known as a haremic cichlid. We found that this fish has helpers, probably related. Cooperative breeding with related helpers has been reported in birds as well as cichlids, but both in birds and cichlids breeding members are of pairs. Thus ; the cooperative breeding of N.savoryi will the first example in haremio mating system. We will examine the relatedness between adults and helpers using samples. We brought ca. 40 individuals of N.savoryi to the laboratory of Osaka City University. Using these live fish, we will conduct aquarium experiment on the cooperative breeding of this fish, Less
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