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Original Research

Ecological niche variation drives morphological differentiation in tropical stream-dwelling newts from Indochina

D. V. Tran

Corresponding Author

D. V. Tran

Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan

Vietnam National University of Forestry, Ha Noi, Vietnam

Correspondence

Dung Van Tran, Graduate School of Human and Environmental Studies, Kyoto University, Yoshida Nihonmatsu-cho, Sakyo-ku, Kyoto 606-8501, Japan.

Email: [email protected]

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D. V. Phan

D. V. Phan

Vietnam National University of Forestry, Ha Noi, Vietnam

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K. A. Lau

K. A. Lau

Vietnam National University of Forestry, Ha Noi, Vietnam

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K. Nishikawa

K. Nishikawa

Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan

Graduate School of Global Environmental Studies, Kyoto University, Kyoto, Japan

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First published: 29 April 2024

Editor: Anthony Herrel

Associate Editor: Anne-Claire Fabre

Abstract

Morphological diversity within organisms can arise from factors other than genetic diversity alone. Local adaptations and combinations of various factors are also involved in shaping morphology. We investigated the relationship between morphological diversity and ecological niche divergence within two related tropical stream-dwelling newt species from Indochina: Paramesotriton deloustali and P. guangxiensis. We identified sexual dimorphism within both species and a significantly larger body size in P. deloustali than in P. guangxiensis. Our findings highlighted that climatic variables strongly influence Asian warty newt distribution, indicating the potential effects of climate change on tropical newt populations. Furthermore, we identified significant intra- and interspecific morphological and niche differentiation across five populations of the two newt species, suggesting that newt morphology is responsive to environmental factors. A significant negative relationship was observed only between ecological niche similarity and geographic distance among various combinations of factors, indicating that the distinct morphology of the study species mirrors ecological adaptation.

Conflict of interest

The authors have no competing interests to declare.

Data availability statement

Data on specific locations (longitude/latitude) of newts cannot be shared publicly because of the need to prevent illegal hunting. The data could be made available to editors or reviewers for checking if necessary. For other purposes, this data are available from the corresponding author (contact via email: [email protected]) or Kanto Nishikawa, Graduate School of Human and Environmental Studies, Kyoto University (email: [email protected]) for researchers who meet the criteria for access to confidential data.