Habitat use and growth strategies of amphidromous fish “ayu” throughout a river system
Abstract Adult spawners are key contributors to fish population dynamics, and thus understanding their life history is essential for effective population management and conservation. The radiogenic Sr isotope ratios (87Sr/86Sr) and ring numbers of adult spawners’ sagitta otoliths were measured to de...
Saved in:
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Nature Portfolio
2025-05-01
|
| Series: | Scientific Reports |
| Subjects: | |
| Online Access: | https://doi.org/10.1038/s41598-025-02988-8 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1849688050074910720 |
|---|---|
| author | Shigeya Nagayama Tamihisa Ohta Ryouji Fujii Morihiro Harada Tsuyoshi Iizuka |
| author_facet | Shigeya Nagayama Tamihisa Ohta Ryouji Fujii Morihiro Harada Tsuyoshi Iizuka |
| author_sort | Shigeya Nagayama |
| collection | DOAJ |
| description | Abstract Adult spawners are key contributors to fish population dynamics, and thus understanding their life history is essential for effective population management and conservation. The radiogenic Sr isotope ratios (87Sr/86Sr) and ring numbers of adult spawners’ sagitta otoliths were measured to determine the habitat use strategy of ayu Plecoglossus altivelis. Six groups of habitat use were identified based on profiles of the otolith 87Sr/86Sr ratio, indicating high contributions of wild ayu (87.2%) and upper-to-middle mainstem habitats for spawning populations. Otolith ring number analyses showed that an early hatch date led to an early river entry and a larger fish size. The upper- and middle-segment (mainly mainstem) residents had earlier hatching and river entry dates than the tributary residents, with middle-segment residents having the largest fish size. These results indicate that early hatched and early river-entering ayu preferentially occupied mainstem habitats and grew large, whereas later-hatched and later-river-entering ayu tended to avoid mainstem habitats and enter tributaries as growth sites. This study can contribute to future habitat conservation efforts and fishery resource management for ayu. |
| format | Article |
| id | doaj-art-e62cdaa00c014cd9874ce1c58a20fddf |
| institution | DOAJ |
| issn | 2045-2322 |
| language | English |
| publishDate | 2025-05-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Scientific Reports |
| spelling | doaj-art-e62cdaa00c014cd9874ce1c58a20fddf2025-08-20T03:22:09ZengNature PortfolioScientific Reports2045-23222025-05-0115111010.1038/s41598-025-02988-8Habitat use and growth strategies of amphidromous fish “ayu” throughout a river systemShigeya Nagayama0Tamihisa Ohta1Ryouji Fujii2Morihiro Harada3Tsuyoshi Iizuka4Center for Environmental and Societal Sustainability, Gifu UniversityFaculty of Science, Academic Assembly, University of ToyamaGifu Prefectural Research Institute for Fisheries and Aquatic EnvironmentsCenter for Environmental and Societal Sustainability, Gifu UniversityDepartment of Earth and Planetary Science, The University of TokyoAbstract Adult spawners are key contributors to fish population dynamics, and thus understanding their life history is essential for effective population management and conservation. The radiogenic Sr isotope ratios (87Sr/86Sr) and ring numbers of adult spawners’ sagitta otoliths were measured to determine the habitat use strategy of ayu Plecoglossus altivelis. Six groups of habitat use were identified based on profiles of the otolith 87Sr/86Sr ratio, indicating high contributions of wild ayu (87.2%) and upper-to-middle mainstem habitats for spawning populations. Otolith ring number analyses showed that an early hatch date led to an early river entry and a larger fish size. The upper- and middle-segment (mainly mainstem) residents had earlier hatching and river entry dates than the tributary residents, with middle-segment residents having the largest fish size. These results indicate that early hatched and early river-entering ayu preferentially occupied mainstem habitats and grew large, whereas later-hatched and later-river-entering ayu tended to avoid mainstem habitats and enter tributaries as growth sites. This study can contribute to future habitat conservation efforts and fishery resource management for ayu.https://doi.org/10.1038/s41598-025-02988-8AyuSpawning adultOtolithsSr isotope ratiosHabitat useLife history |
| spellingShingle | Shigeya Nagayama Tamihisa Ohta Ryouji Fujii Morihiro Harada Tsuyoshi Iizuka Habitat use and growth strategies of amphidromous fish “ayu” throughout a river system Scientific Reports Ayu Spawning adult Otoliths Sr isotope ratios Habitat use Life history |
| title | Habitat use and growth strategies of amphidromous fish “ayu” throughout a river system |
| title_full | Habitat use and growth strategies of amphidromous fish “ayu” throughout a river system |
| title_fullStr | Habitat use and growth strategies of amphidromous fish “ayu” throughout a river system |
| title_full_unstemmed | Habitat use and growth strategies of amphidromous fish “ayu” throughout a river system |
| title_short | Habitat use and growth strategies of amphidromous fish “ayu” throughout a river system |
| title_sort | habitat use and growth strategies of amphidromous fish ayu throughout a river system |
| topic | Ayu Spawning adult Otoliths Sr isotope ratios Habitat use Life history |
| url | https://doi.org/10.1038/s41598-025-02988-8 |
| work_keys_str_mv | AT shigeyanagayama habitatuseandgrowthstrategiesofamphidromousfishayuthroughoutariversystem AT tamihisaohta habitatuseandgrowthstrategiesofamphidromousfishayuthroughoutariversystem AT ryoujifujii habitatuseandgrowthstrategiesofamphidromousfishayuthroughoutariversystem AT morihiroharada habitatuseandgrowthstrategiesofamphidromousfishayuthroughoutariversystem AT tsuyoshiiizuka habitatuseandgrowthstrategiesofamphidromousfishayuthroughoutariversystem |