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Size-dependent growth tactics of a partially migratory fish before migration
Title: | Size-dependent growth tactics of a partially migratory fish before migration |
Authors: | Futamura, Ryo Browse this author | Morita, Kentaro Browse this author →KAKEN DB | Kanno, Yoichiro Browse this author | Kumikawa, Shoji Browse this author | Matsuoka, Yuichi Browse this author | Okuda, Atsushi Browse this author | Sugiyama, Hiroshi Browse this author | Takahashi, Hiroyuki Browse this author | Uchida, Jiro Browse this author | Kishida, Osamu Browse this author →KAKEN DB |
Keywords: | Anadromous fish | Growth period | Growth rate | Life history | Oncorhynchus masou |
Issue Date: | 22-Jan-2022 |
Publisher: | Springer |
Journal Title: | Oecologia |
Volume: | 198 |
Issue: | 2 |
Start Page: | 371 |
End Page: | 379 |
Publisher DOI: | 10.1007/s00442-022-05111-0 |
Abstract: | In many migratory species, smaller migrants suffer higher mortality rates during the risky migration. To minimize the size-selective mortality, migrants with smaller body sizes would need to accelerate growth rates or delay migration timing to attain a large enough body size prior to migration. To test these predictions, we investigated size-dependent patterns of growth rates and migration timing of juvenile masu salmon (Oncorhynchus masou) before their oceanic migration. We tracked uniquely marked individuals in a study population consisted of oceanic migrants and river-dwelling residents using mark-recapture surveys and PIT-tag antenna-reader system. Data supported our predictions about size-dependent growth rates and migration timing. For approximately 6 months before outmigration (i.e., between the decision of migration and the start of migration), eventual migrants grew more than residents if their initial size was smaller, but such a difference in growth rate diminished for fish with larger initial sizes. In addition, smaller eventual migrants delayed the timing of outmigration compared to larger individuals, to attain a larger body size in the river prior to migration. These results suggest that size-selective mortality during migration has shaped size-dependent patterns of the pre-migration growth in migratory masu salmon. Size-conditional changes in growth rate and duration of pre-migration period may be an adaptive tactic for the migratory animals. |
Type: | article |
URI: | http://hdl.handle.net/2115/87777 |
Appears in Collections: | 北方生物圏フィールド科学センター (Field Science Center for Northern Biosphere) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 岸田 治
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