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• Latitudinal cline in species diveristy of Oryzias

• Latitudinal cline in sexual selection in Oryzias spp.

• Latitudinal variation in life histories of Oryzias spp.

Published Papers 【 display / non-display 】

Published Papers 【 display / non-display 】

• Rediscovery of Oryzias hubbsi with notes on its reproductive isolation with O. javanicus

  Daniel F. Mokodongan, Ilham V. Utama, Atsushi J. Nagano, Sau Pinn Woo, Shau Hwai Tan, Satoshi Ansai, Yusuke Takehana, Kazunori Yamahira

  Ichthyological Research ( Springer Science and Business Media LLC )  72   252 - 258   2025.04 [ Peer Review Accepted ]

  Type of publication: Research paper (scientific journal)

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• A new ricefish, <i>Oryzias moramoensis</i> (Adrianichthyidae), described from a mountain waterfall in Southeast Sulawesi, Indonesia

  Utama, IV; Mokodongan, DF; Lawelle, SA; Masengi, KWA; Yamahira, K

  ICHTHYOLOGICAL RESEARCH ( Ichthyological Research )  72   220 - 228   2025.04 [ Peer Review Accepted ]

  Type of publication: Research paper (scientific journal)

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• Allopatric Divergence and Secondary Contact Within a Single River System in a Freshwater Fish Group

  Ilham V. Utama, Ixchel F. Mandagi, Sjamsu A. Lawelle, Kawilarang W. A. Masengi, Atsushi J. Nagano, Junko Kusumi, Kazunori Yamahira

  Freshwater Biology ( Wiley )  70 ( 2 ) e700004   2025.02 [ Peer Review Accepted ]

  Type of publication: Research paper (scientific journal)

  　View Summary

  ABSTRACT Because riverine fishes can disperse along linear river corridors and even between tributaries, allopatric divergence within river systems is limited to large rivers. Within small rivers, such as island rivers, allopatric divergence rarely occurs, and no cases of secondary contact have been reported to date. Two congeneric riverine ricefishes, Oryzias dopingdopingensis and O. landangiensis, are found in the Doping‐doping and Cerekang Rivers, respectively, on Sulawesi Island, which are connected via estuarine waters. These two species are suggested to have diverged in allopatry within this single river system. Phylogenetic and population genetic structure analyses using genome‐wide single nucleotide polymorphisms revealed that Oryzias individuals recently discovered from the downstream Cerekang River are phylogenetically distinct not only from O. dopingdopingensis in the Doping‐doping River but also from O. landangiensis in the upstream Cerekang River. Species tree analysis and demographic model inference revealed that the downstream Cerekang Oryzias diverged from upstream Cerekang Oryzias in allopatry approximately 57,000 generations ago, and they came into secondary contact with each other approximately 22,000 generations ago. Thereafter, the upstream Cerekang population split into two populations, O. landangiensis and O. dopingdopingensis, approximately 14,000 generations ago. We are not aware of any freshwater fish groups that may have experienced both allopatric divergence and secondary contact within such a small single river system. The allopatric divergence and secondary contact within the Cerekang–Doping‐doping River system can be explained by assuming that a lake once existed in this region, where many tectonic lakes have formed and disappeared because of the collision and/or juxtaposition of tectonic subdivisions since the Pliocene/Pleistocene. Gene flow from O. landangiensis to the downstream Cerekang Oryzias is also evident. Although the secondary contact between the upstream and downstream Cerekang populations was estimated to have occurred more than 40,000 years ago, they are still not completely homogenised within the linear corridor of the Cerekang River. This stagnation of homogenisation can be explained by their weak dispersal ability, which may reflect past adaptation to lacustrine environments.

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• <i>Redigobius fotuno</i>, a new limnetic goby from Muna Island, Indonesia (Teleostei: Gobiidae)

  Kobayashi, H; Sumarto, BKA; Mokodongan, DF; Lawelle, SA; Masengi, KWA; Yamahira, K

  ICHTHYOLOGICAL RESEARCH ( Ichthyological Research )  72   55 - 66   2025.01 [ Peer Review Accepted ]

  Type of publication: Research paper (scientific journal)

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• Population structure of the western Indian endemic medaka, <i>Oryzias setnai</i>, inferred from mitochondrial haplotypes

  Anoop, VK; Nuryadi, H; Raghavan, R; Yamahira, K

  ICHTHYOLOGICAL RESEARCH ( Ichthyological Research )    2025 [ Peer Review Accepted ]

  Type of publication: Research paper (scientific journal)

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• Medaka: Biology, Management, and Experimental Protocols (Chapter 2: Medaka and Oryzias species as model organisms and the current status of medaka biological resources)

  山平 寿智 ( Part: Allotment Writing )

  ■■■  2019.11

Other Papers 【 display / non-display 】

Other Papers 【 display / non-display 】

• Different evolutionary histories of cave fishes on the same island

  小林大純, MASENGI Kawilarang W. A., 山平寿智

  日本生態学会大会講演要旨(Web)   68th   2021

   

  J-GLOBAL

• Fitness effects of a gene for sexual dimorphism revealed by genome editing in a Sulawesian fish

  安齋賢, 安齋賢, 安齋賢, 持田浩治, 持田浩治, 藤本真悟, MOKODONGAN Daniel F., MOKODONGAN Daniel F., SUMARTO Bayu Kreshna Adhitya, MASENGI Kawilarang W. A., HADIATY Renny K., 永野惇, 豊田敦, 成瀬清, 山平寿智, 北野潤

  日本生態学会大会講演要旨(Web)   68th   2021

   

  J-GLOBAL

• Non-migratory ecology and systematics of ′′Redigobius penango′′ in Sulawesi

  小林大純, 袰岩美月, MOKODONGAN Daniel F., 安田仁奈, 白井厚太朗, 飯田碧, 山平寿智

  日本魚類学会年会講演要旨   54th (CD-ROM)   2020

   

  J-GLOBAL

• Speciation of medaka fishes in ancient lakes of Sulawesi

  山平寿智

  日本生態学会大会講演要旨(Web)   67th   2020

   

  J-GLOBAL

• Study on existence of the fisheries resources abundance by using environmental deoxyribonucleic acid (e-DNA) approach at fishing grounds in the Sulawesi Sea, Indonesia

  Masengi K.

  IOP Conference Series: Materials Science and Engineering ( IOP Conference Series: Materials Science and Engineering )  567 ( 1 )   2019.08  [Refereed]

   

  DOI

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• Challenging research (development)

  Project Year: 2025.06  -  2028.03 

  Direct: 19,900,000 (YEN)  Overheads: 25,870,000 (YEN)  Total: 5,970,000 (YEN)

• Verification of a novel mode of speciation by mitochondria originated from a different species

  Grant-in-Aid for Scientific Research(A)

  Project Year: 2025.04  -  2028.03 

  Direct: 35,500,000 (YEN)  Overheads: 46,150,000 (YEN)  Total: 10,650,000 (YEN)

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

  Project Year: 2021.04  -  2024.03 

  Direct: 32,400,000 (YEN)  Overheads: 42,120,000 (YEN)  Total: 9,720,000 (YEN)

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

  Project Year: 2021.04  -  2024.03 

  Direct: 32,400,000 (YEN)  Overheads: 42,120,000 (YEN)  Total: 9,720,000 (YEN)

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

  Project Year: 2021.04  -  2024.03 

  Direct: 32,400,000 (YEN)  Overheads: 42,120,000 (YEN)  Total: 9,720,000 (YEN)

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• 2023.10