1998 Fiscal Year Final Research Report Summary
Effect of individuality on interspecific relationships and coexistence mechanism in tropical fish communities
| Project/Area Number |
08640811
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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 | Faculty of Science, Osaka City University |
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Principal Investigator |
KOHDA Masamori Faculty of Science, Osaka City University, Professor, 理学部, 教授 (70192052)
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| Project Period (FY) |
1996 – 1998
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| Keywords | Fishi community / individual variation / hunting technique / territory structure / coexistence mechanism / tropical waters / bio-diversity / related species |
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| Research Abstract |
The effect of individual variation on interspecific relationships and coexistence mechanism have been studied in coral reef fishes in southern Japan. Males of all studied damselfishes had the three territories (nesting, feeding and mating territories) at the same sites, and the largest mating territories seemed to prevent the dominant species from occupation by their feeding territories, and this will facilitate the coexistence of multiple species within a small area. This study, however, should be continued with experimental approach. Individual variations in foraging behavior of a piscivorous trumpetfish has been studied at Kuchierabu Is. Each fish had about 2 hunting techniques from a total of 5-6 techniques for several months. Each fish had large home range, and the variation will be individual specific. This finding will be analogous to that of a piscivorous cichlid. This variation will result in "predatory mutualism" with in this species and/or among piscivores, and the effect should be examined. Associated feeding of benthophagous fishes (wrasses and morwong) has been studied at Uwa Sea. We clalify that this interspecific relationships were widely affected by intraspecific relationships (intraspecific competition, territoriality) of both associating and host fishes. Animal feeding territories rarely overlap widely. We found that the host morwong territories overlapped widely among conspecifics : different sized fish overlapped their territories.
This will be due to size dependent resource partitioning. The results of this research project strongly suggest that individuality will be important to understand the real manners of intra- and interspecific relationships and also fish communities. At Kuchierabu Is and Okinawa, we have study quadrats in which some unfinished researches will be continued.
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