Updated on 2026/06/04

写真a

 
YAMADA Hiroyuki
 
Organization
Faculty of Environmental Science
Department
School of Environmental Science Department of Ecosystem Studies
Title
Lecturer
URL
https://sites.google.com/view/hyamadakosame107amenouo/home
External link

Education

  • 北海道大学大学院水産科学院   海洋生物資源科学専攻

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  • Hokkaido University

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Degree

  • 博士（水産科学） ( 2023.3   北海道大学大学院水産科学院 )

  • 修士（水産科学） ( 2020.3   北海道大学大学院水産科学院 )

Research Field

  • コイ科魚類

  • 認知形質

  • ダム

  • 空間的選別（spatial sorting）

  • 増水

  • 進化生態

  • あくび

  • 稚魚

  • サケ科魚類

  • 行動生態

  • 流下

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Research Experience

  • The University of Shiga Prefecture   School of Environmental Science Department of Ecosystem Studies   Lecturer

    2026.4

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  • Japan Society for the Promotion of Science

    2023.4 - 2026.3

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    Country：Japan

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  • Japan Society for the Promotion of Science

    2020.4 - 2023.3

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    Country：Japan

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Association Memberships

Research Areas

  • Life Science / Evolutionary biology

Committee Memberships

  • 日本生態学会第71回大会   日本生態学会大会ポスター賞審査員  

    2024.3   

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Papers

  • Longitudinal variation in dispersal phenotypes of the fat minnow (Rhynchocypris oxycephala jouyi) in a small stream in western Shikoku, Japan Reviewed

    Hiroyuki Yamada

    Ecological Research   Accepted   2026.5

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  • Experimental evidence that spate-induced downstream dispersal drives spatial sorting of visual–cognitive traits in a stream fish Reviewed

    Hiroyuki Yamada

    Evolutionary Ecology   40 ( 1 )   2026.1

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    Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

    DOI： 10.1007/s10682-025-10370-3

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    Other Link： https://link.springer.com/article/10.1007/s10682-025-10370-3

  • Interpopulation variation in dispersal behavior of fat minnow <i>Rhynchocypris oxycephala jouyi</i> juveniles inhabiting fragmented habitats Reviewed

    Hiroyuki Yamada

    Journal of Fish Biology   107 ( 5 )   1500 - 1507   2025.7

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    Publishing type：Research paper (scientific journal)   Publisher：Wiley  

    Abstract

    In many organisms, including fishes, downstream dispersal is often phenotype‐dependent. Phenotype‐dependent downstream dispersal can generate evolutionary pressure via spatial sorting, which non‐randomly removes phenotypes enhancing downstream dispersal from upstream populations. Spatial sorting due to downstream dispersal could accumulate in fish populations in above‐barrier habitats to which dispersed individuals cannot return, resulting in functional traits that reduce downstream dispersal. This evolutionary mechanism may be more important in smaller above‐barrier habitats where downstream emigration occurs over shorter dispersal distances. This study observed the dispersal behavior of fat minnow Rhynchocypris oxycephala jouyi juveniles in an experimental tank to examine whether juveniles from small above‐barrier habitats show more behaviors favorable for reducing downstream dispersal than those from large above‐barrier habitats. Juveniles from small above‐barrier habitats avoided downstream dispersal for longer durations than those from large above‐barrier habitats, but there was no difference in the frequency of ascending attempts. These results support the notion that behavioral traits of juveniles in small above‐barrier populations have been refined by spatial sorting to reduce downstream dispersal. The finding that interpopulation variation in dispersal behavior occurred only for certain dispersal directions implies that the behavioral consequences of habitat fragmentation are more complex than previously assumed.

    DOI： 10.1111/jfb.15917

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    Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1111/jfb.15917

  • Fish yawn: interpopulation variation in yawning characteristics of juvenile white-spotted char Salvelinus leucomaenis Reviewed

    Reo Nagasaka, Hiroyuki Yamada, Satoshi Wada

    Journal of Ethology   43 ( 2 )   97 - 103   2025.5

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    Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

    DOI： 10.1007/s10164-025-00844-w

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    Other Link： https://link.springer.com/article/10.1007/s10164-025-00844-w/fulltext.html

  • The effects of parasitism on sex allocation of a hermaphroditic acorn barnacle Reviewed

    Masami M Tamechika, Hiroyuki Yamada, Shigeho Ijiri, Yoichi Yusa

    Journal of Evolutionary Biology   38 ( 3 )   417 - 429   2025.1

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    Publishing type：Research paper (scientific journal)   Publisher：Oxford University Press (OUP)  

    Abstract

    Sex allocation theory predicts the adaptive allocation of resources to male versus female reproduction in simultaneous hermaphrodites in response to individual characteristics or environmental factors. Because parasites uptake resources from their hosts, their presence could affect the sex allocation of the hosts. We investigated the effects of infestation status and infestation intensity by the rhizocephalan barnacle Boschmaella japonica on reproduction, including sex allocation, of the host intertidal barnacle Chthamalus challengeri. Feeding activity was also examined as a factor related to resource intake. Both male and female reproductive investment decreased with increasing parasite infestation, and the sex allocation of large-infested hosts was more male-biased than that of large uninfested hosts. Moreover, in contrast to the model prediction that male investment does not change under resource limitation, male investment decreased in infested hosts whose resources were taken by parasites. This reduction in male investment could be explained by changes in mating group size, since infested hosts have shorter penises and consequently are able to access fewer mating partners.

    DOI： 10.1093/jeb/voaf007

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    Other Link： https://academic.oup.com/jeb/article-pdf/38/3/417/61657816/voaf007.pdf

  • Spatial sorting caused by downstream dispersal: implication for morphological evolution in isolated populations of fat minnow inhabiting small streams flowing through terraced rice paddies Reviewed

    Hiroyuki Yamada

    Journal of Evolutionary Biology   37 ( 10 )   1194 - 1204   2024.9

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    Publishing type：Research paper (scientific journal)   Publisher：Oxford University Press (OUP)  

    Abstract

    The evolutionary forces arising from differential dispersal are known as “spatial sorting,” distinguishing them from natural selection arising from differential survival or differential reproductive success. Spatial sorting is often considered to be transient because it is offset by the return of dispersers in many cases. However, in riverine systems, spatial sorting by downstream dispersal can be cumulative in habitats upstream of migration barriers such as weirs or falls, which can block the return of the dispersers. Terraced rice paddies are often found on steep mountain slopes in Japan and often incorporate small streams with numerous migration barriers. This study investigated the morphological features of fat minnow, Rhynchocypris oxycephala jouyi (Cyprinidae), inhabiting above-barrier habitats of the small streams flowing through flood-prone terraced rice paddies and examined their function via a mark–recapture experiment. Although this study did not reveal a consistent pattern across all local populations, some above-barrier populations were characterized by individuals with a thinner caudal peduncle, thinner body, and longer ventral caudal fin lobes than those in neighbouring mainstream populations. A mark–recapture experiment during minor flooding showed that a thinner caudal peduncle and deeper body helped fat minnow avoid downstream dispersal and ascend a small step, and suggested that a longer ventral caudal fin lobe was important for ascending. These results suggest that the caudal morphologies of some above-barrier populations avoid or reduce the risk of downstream dispersal, supporting the idea that spatial sorting shapes functional traits, enhancing the spatial persistence of individuals in upstream habitats.

    DOI： 10.1093/jeb/voae105

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    Other Link： https://academic.oup.com/jeb/article-pdf/37/10/1194/59712574/voae105.pdf

  • Phenotype‐dependent downstream dispersal under ordinary flow conditions in juvenile white‐spotted char Reviewed

    Hiroyuki Yamada, Satoshi Wada

    Ecological Research   39 ( 3 )   330 - 340   2024.3

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    Publishing type：Research paper (scientific journal)   Publisher：Wiley  

    Abstract

    Animal dispersal is often phenotype‐dependent and can exert evolutionary pressures on populations in which it occurs. The evolutionary pressure arising from phenotype‐dependent dispersal is called spatial sorting. We examined the evolutionary pressure arising from spatial sorting (sorting pressure) caused by downstream dispersal in juvenile white‐spotted char Salvelinus leucomaenis under ordinary flow conditions. We conducted outdoor experiments using an artificial channel with 10 steps to investigate the relationship between phenotypic characteristics and the occurrence or distance of downstream dispersal during five daytime hours. Six experiments were conducted using young‐of‐the‐year juveniles collected early in the morning of each experimental day. We focused on two phenotypes, fork length (body size) and station‐holding (SH) behavior, where juveniles remain sedentary on the substrate. Juveniles were assigned to the “SH group” if they exhibited SH behavior for more than 10 s during a 540‐s observation period, and to the “swimming group” if they exhibited SH behavior for less than 10 s. Juveniles in the swimming group had a higher occurrence of downstream dispersal than in the SH group. In addition, large juveniles in the SH group and small juveniles in the swimming group tended to show long dispersal distances. These results suggest an effective sorting pressure against juveniles with active swimming behavior. This sorting pressure may accumulate in isolated char populations located above a tall migration barrier and contribute to the creation and maintenance of the reported interpopulation variation in SH behavior.

    DOI： 10.1111/1440-1703.12455

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  • Interpopulation variation of behavioural and morphological traits that affect downstream displacement of the juvenile white‐spotted charr <i>Salvelinus leucomaenis</i> Reviewed

    Hiroyuki Yamada, Satoshi Wada

    Journal of Fish Biology   102 ( 5 )   1168 - 1176   2023.3

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    Publishing type：Research paper (scientific journal)   Publisher：Wiley  

    DOI： 10.1111/jfb.15373

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    Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1111/jfb.15373

  • Fish yawn: the state-change hypothesis in juvenile white-spotted char <i>Salvelinus leucomaenis</i> Reviewed

    Hiroyuki Yamada, Satoshi Wada

    Journal of Ethology   41 ( 2 )   111 - 117   2023.1

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    Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

    DOI： 10.1007/s10164-023-00777-2

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    Other Link： https://link.springer.com/article/10.1007/s10164-023-00777-2/fulltext.html

  • Morphological evolution reduces downstream displacement in juvenile landlocked salmon Reviewed

    Hiroyuki Yamada, Satoshi Wada

    Evolution   75 ( 7 )   1850 - 1861   2021.6

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    Publishing type：Research paper (scientific journal)   Publisher：Wiley  

    DOI： 10.1111/evo.14281

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    Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1111/evo.14281

  • Personality differences in white-spotted char fry evident between habitats Reviewed

    Hasegawa Ryota, Yamada Hiroyuki, Ishihara Chiaki, Wada Satoshi

    Japanese Journal of Ichthyology   67 ( 1 )   11 - 24   2020.4

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    Language：Japanese   Publisher：The Ichthyological Society of Japan  

    <p>Animal personality, defined as consistent individual differences in behavior across time and/or context, has been associated with individual dispersal tendencies in some species. White-spotted char (<i>Salvelinus leucomaenis</i>) populations, often found in above-dam watersheds in Japanese mountain streams, the dams preventing continuous distribution with lower stream reaches, were subject of a behavioral study comparing above-dam and open-stream behavior of fry. Fries were collected from an above-dam area and two open-stream areas within the Kame River system (southern Hokkaido), and personality quantified by measuring a suite of behaviors, such being repeated two-month later. Above-dam fry showed a shorter swimming duration against a novel object and mirror than open-stream fry. The latency time to catch food in above-dam fry tended to be longer than that of the latter. Swimming duration against a novel object and mirror were significantly correlated when data for both groups combined, but not so when data for each group were analyzed independently. These results suggest that personality traits in whitespotted char fry would be shaped by natural selection acting on each habitat, resulting in differing adaptive personality traits.</p>

    DOI： 10.11369/jji.19-021

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  • Behavioral and morphological comparisons of newly emerged white-spotted char, <i>Salvelinus leucomaenis</i>, in two tributaries of the Kame River, southern Hokkaido, Japan Reviewed

    Yamada Hiroyuki, Enomoto Takashi, Wada Satoshi

    Japanese Journal of Ichthyology   66 ( 2 )   221 - 225   2019.11

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    Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Ichthyological Society of Japan  

    <p>Many local populations of white–spotted char (<i>Salvelinus leucomaenis</i>), a widespread Far East Asian species, persist in above–dam areas, even when erosion control dams prevent continuing upstream movement of individuals. Four morphological characters (dorsal fin height, body depth, caudal peduncle depth, and eye diameter) and two behavioral traits (settlement time and number of foraging actions) of <i>S. leucomaenis</i> fry were compared between two tributaries, one above an erosion control dam and the other an unrestricted stream. Dorsal fin height and caudal peduncle depth were smaller, and settlement time during daytime longer in the above–dam fry, which also showed less frequent foraging behavior than unrestricted stream fry during nighttime, suggesting that the former had unsuitable morphology for swimming and a lower wondering tendency. These characteristics may ultimately aid survival of the above–dam population.</p>

    DOI： 10.11369/jji.18-040

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Awards

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Research Projects

  • 流水圏における空間的選別の研究：普遍性解明と新たなメカニズムの検証

    Grant number：23KJ1667  2023.4 - 2026.3

    日本学術振興会  科学研究費助成事業 特別研究員奨励費  特別研究員奨励費

    山田 寛之

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    Grant amount：\3900000 （ Direct Cost: \3000000 、 Indirect Cost：\900000 ）

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  • Studies on the evolution to resist downstream displacement due to flooding in salmonid populations inhabiting above-dam section

    Grant number：20J20820  2020.4 - 2023.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for JSPS Fellows  Grant-in-Aid for JSPS Fellows

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    Authorship：Principal investigator 

    Grant amount：\2500000 （ Direct Cost: \2500000 ）

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Presentations

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Teaching Experience

  • 人間探求学(環境生態)

    2026.4 Institution：滋賀県立大学

  • 海洋環境学

    2026.4 Institution：滋賀県立大学

  • 環境学野外実習Ⅲ

    2026.4 Institution：滋賀県立大学

  • 環境学野外実習Ⅱ

    2026.4 Institution：滋賀県立大学

  • 環境学野外実習Ⅰ

    2026.4 Institution：滋賀県立大学

  • 科学英語Ⅱ

    2026.4 Institution：滋賀県立大学

  • 科学英語Ⅰ

    2026.4 Institution：滋賀県立大学

  • 環境生態学演習Ⅱ

    2026.4 Institution：滋賀県立大学

  • 環境生態学演習Ⅰ

    2026.4 Institution：滋賀県立大学

  • 科学作文

    2026.4 Institution：滋賀県立大学

  • 環境生物学実験ｂ

    2026.4 Institution：滋賀県立大学

  • 環境生物学実験ａ

    2026.4 Institution：滋賀県立大学

  • 環境生態学特別実習

    2026.4 Institution：滋賀県立大学

  • 環境生態学基礎演習

    2026.4 Institution：滋賀県立大学

  • 水域環境学・同実験

    2026.4 Institution：滋賀県立大学

  • 琵琶湖環境学

    2026.4 Institution：滋賀県立大学

  • 環境動態学特別演習Ⅱ

    2026.4 Institution：滋賀県立大学

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    Level：Postgraduate 

  • 環境動態学特別演習Ⅰ

    2026.4 Institution：滋賀県立大学

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    Level：Postgraduate 

  • 環境動態学特別研究Ⅱ

    2026.4 Institution：滋賀県立大学

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    Level：Postgraduate 

  • 環境動態学特別研究Ⅰ

    2026.4 Institution：滋賀県立大学

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    Level：Postgraduate 

  • 環境動態学プレゼンテーションⅡ

    2026.4 Institution：滋賀県立大学

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    Level：Postgraduate 

  • 環境動態学プレゼンテーションⅠ

    2026.4 Institution：滋賀県立大学

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    Level：Postgraduate 

  • 水圏生態系動態論

    2026.4 Institution：滋賀県立大学

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    Level：Postgraduate 

  • 生態系保全特別演習Ⅱ

    2026.4 Institution：滋賀県立大学

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    Level：Postgraduate 

  • 生態系保全特別演習Ⅰ

    2026.4 Institution：滋賀県立大学

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    Level：Postgraduate 

  • 生態系保全特別研究

    2026.4 Institution：滋賀県立大学

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    Level：Postgraduate 

  • 生態系保全特論

    2026.4 Institution：滋賀県立大学

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    Level：Postgraduate 

  • 河川生物の進化・行動生態学（集中講義）

    2023.9 Institution：愛媛大学理学部

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Media Coverage

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