Suzuki, Atsushi

写真a

Affiliation

School of Medicine (Hiyoshi)

Position

Associate Professor

External Links

Other Affiliation 【 Display / hide

  • Keio Research Center for the Liberal Arts, 所員

  • Research and Education Center for Natural Sciences, 所員

Career 【 Display / hide

  • 1988.04
    -
    1991.03

    浜松医科大学 ,教務員

  • 1991.04
    -
    1999.03

    大学助手(医学部)

  • 1999.04
    -
    Present

    大学専任講師(医学部)

  • 2009.04
    -
    Present

    大学准教授(医学部)

Academic Background 【 Display / hide

  • 1983.03

    Nagoya University, Faculty of Science, 生物学科

    University, Graduated

  • 1985.03

    Nagoya University

    Graduate School, Completed, Master's course

  • 1988.03

    Nagoya University

    Graduate School, Withdrawal after completion of doctoral course requirements, Doctoral course

Academic Degrees 【 Display / hide

  • 博士(理学), Kanazawa University, Dissertation, 1998.09

 

Research Areas 【 Display / hide

  • Life Science / Morphology and anatomical structure

  • Life Science / Biodiversity and systematics

Research Keywords 【 Display / hide

  • tardigrade

  • natural history

  • Meiofauna

  • Antarctica

 

Books 【 Display / hide

  • Species Diversit of Animals in Japan. Motokawa M, Kajihara H (eds)

    SUZUKI C ATSUSHI, Springer Japan, 2017

    Scope: Chapter 10. Tardigrade Research in Japan

  • クマムシ?!小さな怪物

    SUZUKI ATSUSHI, 岩波書店, 2006.08

    Scope: 112

Papers 【 Display / hide

  • Redescription of Milnesium alpigenum Ehrenberg, 1853 (Tardigrada: Apochela) and a description of Milnesium inceptum sp. Nov., a tardigrade laboratory model

    Morek W., Suzuki A., Schill R., Georgiev D., Yankova M., Marley N., Michalczyk Ł.

    Zootaxa (Zootaxa)  4586 ( 1 ) 35 - 64 2019

    ISSN  11755326

     View Summary

    Copyright © 2019 Magnolia Press Intra- and interspecific variability, being at the very core of alpha taxonomy, has been a long-standing topic of debate among tardigrade taxonomists. Early studies tended to assume that tardigrades exhibit wide intraspecific variation. However, with more careful morphological studies, especially those incorporating molecular tools that allow for an independent verification of species identifications based on phenotypic traits, we now recognise that ranges of tardigrade intraspecific variability are narrower, and that differences between species may be more subtle than previously assumed. The taxonomic history of the genus Milnesium, and more specifically that of the nominal species, M. tardigradum described by Doyère in 1840, is a good illustration of the evolution of views on intraspecific variability in tardigrades. The assumption of wide intraspecific variability in claw morphology led Marcus (1928) to synonymise two species with different claw configurations, M. alpigenum and M. quadrifidum, with M. tardigradum. Currently claw configuration is recognised as one of the key diagnostic traits in the genus Milnesium, and the two species suppressed by Marcus have recently been suggested to be valid. In this study, we clarify the taxonomic status of M. alpigenum, a species that for nearly a century was considered invalid. We redescribe M. alpigenum, using a population collected from the locus typicus, by the means of integrative taxonomy, i.e. including light microscopy, scanning electron microscopy, ontogenetic observations, and genetic barcoding. Moreover, the redescription of M. alpigenum allowed us to verify the uncertain taxonomic status of two popular laboratory models that were originally considered to be M. tardigradum; though one was recently reiden-tified as M. cf. alpigenum. Our analysis showed that both laboratory strains, despite being morphologically and morphometrically nearly identical to M. alpigenum, in fact represent a new species, M. inceptum sp. nov. The two species, being disnguishable only by statistical morphometry and/or DNA sequences, are the first example of pseudocryptic species in tardigrades.

  • Untangling the Echiniscus Gordian knot: Stellariscus gen. nov. (Heterotardigrada: Echiniscidae) from Far East Asia

    Gasiorek P, SUZUKI C ATSUSHI, Kristensen RM, Lachowska-Cierlik D, Michalczyk L

    Invertebrate Systematics (Invertebrate Systematics)  32 ( 5 ) 1234 - 1247 2018.10

    Research paper (scientific journal), Joint Work, Accepted,  ISSN  14455226

     View Summary

    Species constituting the family Echiniscidae are highly derived, armoured and inhabit terrestrial habitats, in contrast to other heterotardigrades that are predominantly marine. The genus Echiniscus C.A.S. Schultze, 1840, nominal for the family Echiniscidae, is currently the most speciose tardigrade genus. However, the great morphological variability, in comparison with other heterotardigrade genera, suggests the polyphyletic character of the genus. Here, we analyse new specimens of Echiniscus pseudelegans Séméria, 1994 collected in Japan and conclude that the species as well as two other related taxa, E. elegans Richters, 1907 and E. latifasciatus Dudichev and Biserov, 2000, represent a new genus, Stellariscus, gen. nov. The new genus is characterised by a mixture of peculiar morphological apomorphies: black eyes, star-like dorsal plate sculpturing, no trunk appendages (only cephalic cirri present), two types of ventral plates, and striking sexual dimorphism in both qualitative and quantitative traits. Morphological phylogeny of the family Echiniscidae suggests a close affinity between Stellariscus, Hypechiniscus Thulin, 1928 and Pseudechiniscus Thulin, 1911. The polyphyletic status of both Echiniscus and Testechiniscus Kristensen, 1987 is also inferred. The taxonomic significance of ventral armature in echiniscid phylogeny and taxonomy is discussed.

  • Comparison of sexual behavior in two species of Macrobiotidae (Tardigrada: Eutardigrada)

    Sugiura K, Minato H, SUZUKI C ATSUSHI, Arakawa K, Kunieda T, Matsumoto M

    Zoological Science (Zoological Science)  in press ( 2 ) 120 - 127 2018

    Research paper (scientific journal), Joint Work, Accepted,  ISSN  02890003

     View Summary

    Reproductive strategy is an important aspect of understanding biological diversity. In tardigrades, several reproductive modes are known, including sexual reproduction. However, their mating behavior remains only rarely observed in most species, or entirely unknown especially in the freely ovipositing eutardigrades. In this study, we cultured two sexually reproducing tardigrade species that lay eggs freely, Paramacrobiotus sp. TYO strain and Macrobiotus shonaicus, to investigate and compare their courtship, mating, and chromosome morphology. Mating behavior was observed and recorded in both species. The entire sequence of the mating behavior, including their courtship, was categorized into five discrete steps common to two species as follows: [1] Tracking: a male tracks and orientates toward a female; [2] Touching: the male touches the cloaca of the female; [3] Standstill: the female stops her movement until male ejaculation is over; [4] Ejaculation: the male curls his caudal end and ejaculates into the cloaca from close range; [5] Contracting: the female contracts her ventral side after ejaculation to capture the spermatozoa, which were deposited in the external environment in close proximity to the cloaca. Some notable differences between the two species were observed in the steps 3-4. First ovipositions were observed at 40 min in Paramacrobiotus sp. TYO strain, and a few days after mating in M. shonaicus, respectively. Comparisons of before and after mating chromosome morphology indicated that oocytes were arrested at the metaphase I in both species. A spermatozoon attached to the interior of the chorion of the laid egg.

  • Oncholaimus langhovdensis sp. nov. (Nematoda

    Shimada Daisuke, Suzuki Atsushi C., Tsujimoto Megumu, Imura Satoshi, Kakui Keiichi

    Species Diversity 22 ( 2 ) 151 - 159 2017.12

    ISSN  1342-1670

     View Summary

    <p>A new species of free-living marine nematode, Oncholaimus langhovdensis sp. nov., is described from the intertidal zone of Langhovde (near Syowa Station), Dronning Maud Land, East Antarctica. It closely resembles 11 congeners in the conico-cylindrical tail shape present in males and amphid and excretory pore positions, short spicules, and Demanian system structure present in females. However, it mainly differs from these congeners in body size, de Man's ratios, tail length and shape, and Demanian system structure present in females. Oncholaimus langhovdensis sp. nov. also resembles four congeners known only by females, but it can be distinguished from them based on the tail length and uvette position. In addition to O. langhovdensis sp. nov., two undescribed species (Tripyloididae gen. sp. and Axonolaimidae gen. sp.) and four unidentified species (Sphaerolaimus sp., Oncholaimidae gen. sp., Comesomatidae gen. sp., and Chromadorida fam. gen. sp.) were found from the same locality.</p>

  • Meiofaunal richness in highly acidic hot springs in Unzen-Amakusa National Park, Japan, including the first rediscovery attempt for mesotardigrada

    Suzuki Atsushi C., Kagoshima Hiroshi, Chilton Glen, Grothman Gary T., Johansson Carl, Tsujimoto Megumu

    Zoological Science 34 ( 1 ) 11 - 17 2017.02

    ISSN  0289-0003

     View Summary

    <p>Extreme environments sometimes support surprisingly high meiofaunal diversity. We sampled runoff from the acidic hot springs of Unzen, Japan. This is the type locality of Thermozodium esakiiRahm, 1937, the only tardigrade in the class Mesotardigrada, which remains contentious in the absence of corroboration or supporting specimens. Our sampling revealed at least three species of arthropods, four rotifers, and five nematodes living in the hot (ca. 40°C) and acidic (ca. pH 2.5) water, but no tardigrades.</p>

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Papers, etc., Registered in KOARA 【 Display / hide

Presentations 【 Display / hide

  • Ultrastructural study on oogenesis of Actinarctus doryphorus (Arthrotardigrada: Halechiniscidae)

    SUZUKI ATSUSHI C and Kristensen RM

    10th International Symposium on Tardigrada (Catania, Italy) , 

    2006.06

    Oral presentation (general)

  • Appearance of males from a thelytokous strain of Milnesium tardigradum

    SUZUKI ATSUSHI C.

    10th International Symposium on Tardigrada (Catania, Italy) , 

    2006.06

    Poster presentation

  • オニクマムシMilnesium tardigradumの卵形成

    鈴木 忠

    日本動物学会第74回大会 (函館) , 

    2003.09

    Poster presentation, 日本動物学会

  • Oogenesis of Milnesium tardigradum.

    SUZUKI AC

    9th International Symposium on Tardigrada (St Pete Beach, Florida USA) , 

    2003.07

    Poster presentation

  • 緩歩動物オニクマムシの飼育とその生活史

    鈴木 忠

    日本動物学会第72回大会 (福岡) , 

    2001.10

    Poster presentation, 日本動物学会

Works 【 Display / hide

  • カリキュラム委員会委員

    2003.10
    -
    2005.09

    Other

  • 自主学習小委員会委員

    2003.10
    -
    2005.09

    Other

  • カリキュラム委員会委員

    2001.10
    -
    2003.09

    Other

  • 自主学習小委員会委員

    2001.10
    -
    2003.09

    Other

  • 自主学習小委員会委員

    1999.10
    -
    2001.09

    Other

Awards 【 Display / hide

  • Zoological Science Award 2004

    SUZUKI ATSUSHI, 2004.09, (財)日本動物学会, Life history of Milnesium tardigradum Doyère (Tardigrada) under a rearing envionment.

    Type of Award: Other

  • Zoological Science Award

    2004.09, Zoological Society of Japan, Life history of Milnesium tardigradum Doyère (Tardigrada) under a rearing environment. Zoological Science 20: 49-57, 2003

 

Courses Taught 【 Display / hide

  • LABORATORY OF BIOLOGY

    2022

  • BIOLOGY2

    2022

  • LABORATORY OF BIOLOGY

    2021

  • BIOLOGY2

    2021

  • LABORATORY OF BIOLOGY

    2020

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Courses Previously Taught 【 Display / hide

  • 生物学実験

    Keio University

    2018.04
    -
    2019.03

    Full academic year, Laboratory work/practical work/exercise, Within own faculty, 4h, 118people

  • 生物学II

    Keio University

    2018.04
    -
    2019.03

    Spring Semester, Within own faculty, 2h, 118people

 

Memberships in Academic Societies 【 Display / hide

  • The Zoological Society of Japan

     
  • 日本動物分類学会

     

Committee Experiences 【 Display / hide

  • 2007.01
    -
    2009.12

    生物科学ニュース編集委員会幹事, (財)日本動物学会