Ikeda Yuzuru

写真a

Title

Professor

Researcher Number(JSPS Kakenhi)

30342744
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Current Affiliation Organization 【 display / non-display 】

  • Duty   University of the Ryukyus   Faculty of Science   Chemistry, Biology and Marine Science   Professor  

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External Career 【 display / non-display 】

  • 2005.04
    　
    　

    University of the Ryukyus  

  • 2005.04
    　
    　

    University of the Ryukyus, Faculty of Science, Department of Chemistry, Biology, and Marine Science, Marine Biology, Professor  

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Affiliated academic organizations 【 display / non-display 】

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    THE JAPANESE SOCIETY OF FISHERIES SCIENCE 

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    JAPANESE SOCIETY FOR AQUACULTURE SCIENCE 

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    JAPAN ETHOLOGICAL SOCIETY 

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    THE ZOOLOGICAL SOCIETY OF JAPAN 

  • 1989.04
    -
    Now
     

    The Japanese Society of Fisheries Science 

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Research Areas 【 display / non-display 】

  • Life Science / Animal physiological chemistry, physiology and behavioral biology

  • Life Science / Aquatic bioproduction science

  • Life Science / Aquatic bioproduction science

  • Life Science / Animal physiological chemistry, physiology and behavioral biology

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Research Theme 【 display / non-display 】

  • Aquaculture of Cephalopods

  • Sociality and Communication of Cephalopods

  • Natural History of Cephalopods

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Published Papers 【 display / non-display 】

  • Evolutionary history influences the microbiomes of a female symbiotic reproductive organ in cephalopods

    Nidhi Vijayan, Sarah J. McAnulty, Gustavo Sanchez, Jeffrey Jolly, Yuzuru Ikeda, Michele K. Nishiguchi, Elodie Réveillac, Camino Gestal, Blake L. Spady, Diana H. Li, Benjamin P. Burford, Allison H. Kerwin, Spencer V. Nyholm

    Applied and Environmental Microbiology ( American Society for Microbiology )  90 ( 3 )   2024.02 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

    　View Summary

    ABSTRACT Many female squids and cuttlefishes have a symbiotic reproductive organ called the accessory nidamental gland (ANG) that hosts a bacterial consortium involved with egg defense against pathogens and fouling organisms. While the ANG is found in multiple cephalopod families, little is known about the global microbial diversity of these ANG bacterial symbionts. We used 16S rRNA gene community analysis to characterize the ANG microbiome from different cephalopod species and assess the relationship between host and symbiont phylogenies. The ANG microbiome of 11 species of cephalopods from four families (superorder: Decapodiformes) that span seven geographic locations was characterized. Bacteria of class Alphaproteobacteria, Gammaproteobacteria , and Flavobacteriia were found in all species, yet analysis of amplicon sequence variants by multiple distance metrics revealed a significant difference between ANG microbiomes of cephalopod families (weighted/unweighted UniFrac, Bray–Curtis, P = 0.001). Despite being collected from widely disparate geographic locations, members of the family Sepiolidae (bobtail squid) shared many bacterial taxa including (~50%) Opitutae (Verrucomicrobia) and Ruegeria (Alphaproteobacteria) species. Furthermore, we tested for phylosymbiosis and found a positive correlation between host phylogenetic distance and bacterial community dissimilarity (Mantel test r = 0.7). These data suggest that closely related sepiolids select for distinct symbionts from similar bacterial taxa. Overall, the ANGs of different cephalopod species harbor distinct microbiomes and thus offer a diverse symbiont community to explore antimicrobial activity and other functional roles in host fitness. IMPORTANCE Many aquatic organisms recruit microbial symbionts from the environment that provide a variety of functions, including defense from pathogens. Some female cephalopods (squids, bobtail squids, and cuttlefish) have a reproductive organ called the accessory nidamental gland (ANG) that contains a bacterial consortium that protects eggs from pathogens. Despite the wide distribution of these cephalopods, whether they share similar microbiomes is unknown. Here, we studied the microbial diversity of the ANG in 11 species of cephalopods distributed over a broad geographic range and representing 15–120 million years of host divergence. The ANG microbiomes shared some bacterial taxa, but each cephalopod species had unique symbiotic members. Additionally, analysis of host–symbiont phylogenies suggests that the evolutionary histories of the partners have been important in shaping the ANG microbiome. This study advances our knowledge of cephalopod–bacteria relationships and provides a foundation to explore defensive symbionts in other systems.

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  • Relationship between seasonal seagrass growth and egg case dynamics of the oval squid (Sepioteuthis lessoniana Férussac in Lesson, 1832) in the coastal waters of the Ryukyu Archipelago

    Sho Kimoto, Ritsuki Kawabata, Yuzuru Ikeda

    Regional Studies in Marine Science ( Elsevier BV )  67   103190 - 103190   2023.12 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

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  • Allometry for Eyes and Optic Lobes in Oval Squid (Sepioteuthis lessoniana) with Special Reference to Their Ontogenetic Asymmetry

    Yuma Sakurai, Yuzuru Ikeda

    Symmetry ( MDPI AG )  14 ( 4 ) 644 - 644   2022.03 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

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    Eyes develop in relation to body size and brain area for visual processing in some vertebrates. Meanwhile, it is well known that many animals exhibit left–right asymmetry in both morphology and behavior, namely, lateralization. However, it remains unclear whether the eyes and visual processing brain areas synchronously develop for their asymmetry. Oval squid (Sepioteuthis lessoniana) exhibits lateralization of optic lobe volume and left or right eye usage toward specific targets during their ontogeny. We address the question of how left–right asymmetry of the eyes and optic lobes exhibit an allometric pattern. To examine this question, we estimated the left and right volumes of eyes and optic lobes using microcomputed tomography. We found that, for the optic lobe volume, the right enlargement that appeared at ages 45 and 80 days then shifted to the left at age 120 days. In contrast, the volume of eyes did not show any left–right asymmetries from hatching to age 120 days. We also found that the volume of the eyes and optic lobes showed a slower increase than that of the whole-body size. Within these two visually related organs, the eyes grew faster than the optic lobes until age 120 days. These results are discussed in the context of the survival strategy of oval squid that form schools, two months post-hatching.

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  • Visual and brain lateralization during the posthatching phase in squid under solitary and group conditions

    Yuma Sakurai, Yuzuru Ikeda

    Animal Behaviour ( Elsevier BV )  183   13 - 28   2022.01 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

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  • Evaluation of Visual and Tactile Perception by Plain-Body Octopus (<i>Callistoctopus aspilosomatis</i>) of Prey-Like Objects.

    Kawashima S, Ikeda Y

    Zoological science ( Zoological Science )  38 ( 6 ) 495 - 505   2021.12 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

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      PubMed

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Books 【 display / non-display 】

  • Abdopus aculeatus, the Prickly octopus. In Rosa R, Gleadall IG, Pierce GJ (eds.), Octopus Biology and Ecology

    ( Part: Allotment Writing )

    2024.06

    ASIN

  • Past, present, and future trends in octopus research. In Rosa R, Gleadall IG, Pierce GJ (eds.), Octopus Biology and Ecology

    ( Part: Allotment Writing )

    2024.06

    ASIN

  • Color Change in Cephalopods. In (H. Hashimoto, M. Goda, R. Futahashi, R. Kelsh, T. Akiyama, eds.) Pigments, Pigment Cells and Pigment Patterns

    Yuzuru Ikeda ( Part: Joint Editing and Writing )

    Springer  2021.07

  • Color Change in Cephalopods. In (H. Hashimoto, M. Goda, R. Futahashi, R. Kelsh, T. Akiyama, eds.) Pigments, Pigment Cells and Pigment Patterns

    ( Part: Allotment Writing )

    2021.06

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Other Papers 【 display / non-display 】

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Presentations 【 display / non-display 】

  • 知の旧家に住まう者たち:イカ・タコの行動から

    池田 譲

    NICTオープンサミット in 沖縄 -量子情報、生命システムが創る情報通信技術-  2018  -  2018 

  • 頭足類における表情もしくは代替的なシグルナルによる社会的相互作用研究

    池田 譲

    日本心理学会シンポジウム生物種を越えてユニバーサルな「表情」：ヒト、犬、ラット、タコ・イカから考える  2017.09  -  2017.09 

  • イカ・タコの心を探る

    池田 譲

    にいがた市民大学講座 人間と動物のつながり–動物が私たちに教えてくれること–  2017.06  -  2017.06 

  • 知を武具に生きるものたち–イカとタコにみる心と社会–

    池田 譲

    新潟大学人文社会・教育科学系附置間主観的感性論研究センター主催公開講演会  2017.06  -  2017.06 

  • What’s the cephalopod megalobrain for?

    池田 譲

    International Symposium on Evolution of Brain, Cognition, and Emotion  2017  -  2017 

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Academic Awards 【 display / non-display 】

  • Zoological Science Award and Fujii Award

    2022.09     Evaluation of Visual and Tactile Perception by Plain-body Octopus (Callistoctopus aspilosomatis) of Prey-like Objects

    Winner: Kawashima, S., Ikeda, Y.

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Grant-in-Aid for Scientific Research 【 display / non-display 】

  • Grant-in-Aid for Scientific Research(B)

    Project Year: 2021.04  -  2025.03 

    Direct: 13,200,000 (YEN)  Overheads: 17,160,000 (YEN)  Total: 3,960,000 (YEN)

  • Grant-in-Aid for Scientific Research(B)

    Project Year: 2021.04  -  2024.03 

  • Challenging research (sprout)

    Project Year: 2019.06  -  2021.03 

    Direct: 5,000,000 (YEN)  Overheads: 6,500,000 (YEN)  Total: 1,500,000 (YEN)

  • Challenging research (sprout)

    Project Year: 2019.06  -  2021.03 

    Direct: 5,000,000 (YEN)  Overheads: 6,500,000 (YEN)  Total: 1,500,000 (YEN)

  • An exploratory study on comparative social cognitive science: a biological basis of personal space

    Challenging research (sprout)

    Project Year: 2019.06  -  2021.03 

    Investigator(s): KAWAI Nobuyuki 

    Direct: 5,000,000 (YEN)  Overheads: 6,500,000 (YEN)  Total: 1,500,000 (YEN)

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    This study aimed to establish a new study domain called “virtual reality comparative and social cognitive science". We created computer graphic (CG) animal models in virtual reality (VR) environments and tested whether live animals interact with those CG animals. Marmoset monkeys stopped their on-going behavior when they watched a CG marmoset approaching but not when they watched that of static image. We gave instructions on various chromatic body patterns of cuttlefish to deep learning system, which enabled us to discriminate six chromatic patterns (uniform, circle, disruptive, dark, line and eyespots) of cuttlefish with successful rate over 77 % within 0.02 sec analysis time. We also succeeded to create the CG of cuttlefish that exhibit the six chromatic patterns above and can move as well. This is the most elaborate CG system of cephalopods so far. By using these systems, we can expect to develop unique behavioral test for animal social behavior in the future.

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Social Activity 【 display / non-display 】

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Media Coverage 【 display / non-display 】

  • タコは…宇宙から来た!?  TV or radio program

    フジテレビ  世界の何だコレ!?ミステリー 2時間SP  2024.4

    Author： Myself 

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    ゲスト出演し、タコの宇宙起源説について解説した。

  • 南の楽園 石垣島のショアエギング 価値ある一杯を求めて  TV or radio program

    BS-TBS  釣り百景  2024.3

    Author： Myself 

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    アオリイカについて解説した。

  • おいしいだけじゃない！神秘の知的生命体「タコ」  TV or radio program

    NHK Eテレ  サイエンスZERO  2023.12

    Author： Myself 

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    おいしいだけじゃない！神秘の知的生命体「タコ」にゲスト出演し、タコについて解説した。

  • マダコ  TV or radio program

    BS釣りビジョン  熱愛！サカナ図鑑  2023.9

    Author： Myself 

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    ゲスト出演し、マダコについて語った。

  • タコについて  TV or radio program

    TOKYO FM /JFM38局  レコレール  2023.8

    Author： Myself 

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    ゲスト出演し、タコについて語った。

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