| Project/Area Number |
11640633
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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 | EHIME UNIVERSITY |
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Principal Investigator |
YANAGISAWA Yasunobu Faculty of Science, Professor, 理学部, 教授 (90116989)
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| Co-Investigator(Kenkyū-buntansha) |
OKUDA Noboru JSPS Fellow, 特別研究員
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 2000: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1999: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Keywords | Sex rele reversal / Reproductive strategy / Mouthbrooding / Territory / Filial cannib alism / Hetero cannib alism / Apogonidae / Parental care / 生理的コンディション |
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| Research Abstract |
Cardinalfishes (family Apogonidae) are distributed widely in tropical and temperate waters and known as paternal mouthbrooders. Their sex roles are usually reversed, that is, females are the primary competitors for access to mates. Among cardinalfishes, male and female strategies in reproduction differ interspecifically depending on their ecology. In the field research at Murote Beach, Shikoku, Japan, in 1999 and 2000, our attention focused on the function of territories of female Apogon notatus that are formed from two or three months before spawning and kept throughout the breeding season. Main opponents against which females defended their territories were not conspecific females but schooling males. At the moment of spawning when the egg mass was transferred from the female to the male, the mass was often eaten by schooling males and wrasses. The frequency of this cannibalism rose late in the breeding season when the proportion of schooling individuals in the population increased. These and other results indicated that the primary function of female territories is to avoid egg predation from schooling males.
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