Morphological Variations of the Mudskipper Oxuderces nexipinnis (Cantor, 1849) in the Mekong Delta, Vietnam
Main Article Content
Abstract
This study provides data on the morphological variations of the mudskipper Oxuderces nexipinnis. A total of 616 specimens (223 females and 393 males) were collected continuously over a 12-month period (from August 2024 to July 2025) at four coastal sites in Vinh Long Province, Ca Mau Province, and Can Tho City. The analysis revealed that morphological traits such as eye diameter (ED), body depth (BD), head length (HL), and mouth width (MD) varied significantly between sexes, whereas interorbital distance (IO) showed no marked difference between males and females. All five traits (ED, IO, BD, MD, HL) fluctuated with season and ecological zone. The ratios ED/HL, IO/HL, BD/HL, and MD/HL were influenced jointly by sex, season, and sampling location. Notably, the interaction between sex and ecological zone had significant effects on ED/HL and MD/HL, indicating that sexual dimorphism in morphology varied across habitats. Moreover, the interaction between season and ecological zone strongly affected ED/HL and IO/HL, suggesting a potential morphological response to hydrological fluctuations and food availability between dry and wet seasons. These findings provide useful insights for species identification and enhance the understanding of ecological adaptation in O. nexipinnis within the Mekong Delta.
Keywords:
Oxuderces nexipinnis, mudskipper, Mekong Delta, morphological traits.
References
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[2] A. V. Gispert, S. Yavno, J. Naspleda, L. Zamora, R. M. Amich, M. G. Fox, Patterns of Morphological Variation among Native and Non-native Pumpkinseed (Lepomis gibbosus) Populations: Shared and Unique Aspects of Diversification, Environmental Biology of Fishes, Vol. 100, 2017, pp 969-980,
https://doi.org/10.1007/s10641-017-0626-x.
[3] R. B. Langerhans, T. J. DeWitt, Shared and Unique Features of Evolutionary Diversification, The American Naturalist, Vol. 164, 2004, pp. 335-349, https://doi.org/ 10.1086/422857.
[4] Q. Q. Cheng, D. R. Lu, L. Ma, Morphological Differences between Close Populations Discernible by Multivariate Analysis: A Case Study of Genus Coilia (Teleostei: Clupeiforms), Aquatic Living Resources, Vol. 18, 2005, pp. 187-192, https://doi.org/ 10.1051/Alr:2005020.
[5] M. A. B. Siddik, M. A. Hanif, M. R. Chaklader, A. Nahar, S. Mahmud, Fishery Biology of Gangetic Whiting Sillaginopsis panijus (Hamilton, 1822) Endemic to Ganges Delta, Bangladesh, The Egyptian Journal of Aquatic Research, Vol. 41, No. 4, 2015, pp. 307–313, https://doi.org/10.1016/j.ejar.2015.11.001.
[6] M. R. Chaklader, M. A. B. Siddik, A. N. Ashfaqun Nahar, M. A. Hanif, M. J. Alam, S. M. Sultan Mahmud, Morphometric Parameters and Allometric Growth in Paradise Threadfin Polynemus paradiseus (Linnaeus, 1758) from a Coastal River of Bangladesh, Journal of Aquaculture Research and Development, Vol. 7, Art, No. 417, 2016, https://doi.org/10.4172/2155-9546.1000417.
[7] H. AnvariFar, A. Khyabani, H. Farahmand, S. Vatandoust, H. AnvariFar, S. Jahageerdar, Detection of Morphometric Differentiation between Isolated Up-and Downstream Populations of Siah Mahi (Capoeta capoeta gracilis) (Pisces: Cyprinidae) in the Tajan River (Iran), Hydrobiologia, Vol. 673, 2011, pp. 41-52, https://doi.org/ 10.1007/S10750-011-0748-7.
[8] Q. M. Dinh, T. T. H. Lam, T. H. D. Nguyen, Study on External Morphology of Butis humeralis in the Coastline Regions of Mekong Delta, Science and Technology Journal of Agriculture and Rural Development, No. 10, 2021, pp. 146–153 (in Vietnamese).
[9] J. S. Nelson, T. C. Grande, M. V. H. Wilson, Fishes of the World, 5th ed., John Wiley and Sons, Hoboken, USA, 2016, pp. 326–330.
[10] H. V. Nguyen, Freshwater Fish of Vietnam, Agriculture Publishing House, Hanoi, Vol. II, 2005 (in Vietnamese).
[11] J. S. Nelson, Fishes of the World, Wiley, 2006.
[12] Y. D. Mai, T. V. Nguyen, T. V. Nguyen, Y. H. Le, L. B. Hua, Identification of Freshwater Fishes of South Vietnam, Ha Noi: Science and Technology Publishing House, 1992 (in Vietnamese).
[13] D. D. Tran, K. Shibukawa, T. P. Nguyen, P. H. Ha, X. L. Tran, V. H. Mai, K. Utsugi, Fishes of Mekong Delta, Vietnam, Can Tho University Publisher, 2013 (in Vietnamese).
[14] Q. M. Dinh, T. H. D. Nguyen, T. T. H. Lam, T. T. K. Nguyen, G. V. Tran, Z. Jaafar, Foraging Ecology of the Amphibious Mudskipper Periophthalmus chrysospilos (Gobiiformes: Gobiidae), PeerJ, Vol. 9, 2021, pp. E12582, https://doi.org/10.7717/peerj.12582.
[15] V. H. Mai, Reproductive Ecology of Two Species of the Mudskippers, Periophthalmodon septemradiatus and Periophthalmus modestus, PhD Thesis, Nagasaki University, 2020, pp. 1-79.
[16] G. Polgar, V. Bartolino, Size Variation of Six Species of Oxudercine Gobies along the Intertidal Zone in a Malayan Coastal Swamp, Marine Ecology Progress Series, Vol. 409, 2010, pp. 199-212, https://doi.org/10.3354/meps08597
[17] L. R. Parenti, Z. Jaafar, The Natural Distribution of Mudskippers, In Fishes Out of Water, CRC Press, 2017, pp. 37-68.
[18] L. T. T. Vo, A. N. Tran, T. Q. Phan, Q. M. Dinh, Morphometrics Variations of Mystus mysticetus Roberts, 1992 in the Mekong Delta, Vietnam, Aquaculture, Aquarium, Conservation and Legislation, Vol. 14, 2021, pp. 3423-3431.
[19] Q. M. Dinh, Aspects of Reproductive Biology of the Red Goby Trypauchen vagina (Gobiidae) from the Mekong Delta, Journal of Applied Ichthyology, Vol. 34, 2018, pp. 103-110, https://doi.org/10.1111/jai.13521.
[20] Z. Jaafar, E.O. Murdy, Fishes Out of Water: Biology and Ecology of Mudskippers, CRC Press, United States, 2017.
[21] E. O. Murdy, A Taxonomic Revision and Cladistic Analysis of the Oxudercine Gobies (Gobiidae, Oxudercinae), Australian Museum Journal, Vol. 11, 1989, pp. 1-93, https://doi.org/10.3853/j.0812-7387.11.1989.93.
[22] P. L. H. Nguyen, L. T. C. Tran, T. T. A. Phan, T. K. Nguyen, L. T. T. Vo, Q. M. Dinh, Morphometrics Allometry Changes and Sexual Dimorphism in Caragobius urolepis (Gobiiformes: Gobiidae), Veterinary Integrative Sciences, Vol. 21, 2023, pp. 29-36, https://doi.org/10.12982/VIS. 2023.003.
[23] D. T. Nguyen, T. K. A. Tran, T. Nguyen, Body Shape Variations of Tank Goby Glossogobius giuris (Hamilton 1822) in three Distinct Water Bodies of Central Vietnam, Croatian Journal of Fisheries, Vol. 82, No. 3, 2024, pp. 91–100, https://doi.org/10.2478/cjf-2024-0012.
[24] H. Le Trung, M. Q. Dinh, V. U. Hua, H. D. T. Nguyen, The Morphological Measurement Variations of Periophthalmus chrysospilos along the Coastline in the Mekong Delta, VNU Journal of Science: Natural Sciences and Technology, Vol. 38, No. 1, 2021, https://doi.org/10.25073/2588-1140/vnunst.5245.
[25] T. Ta, N. Chu, N. Nguyen, H. Tran, T. Tran, L. Ha, Morphometrics and Body Condition of Glossogobius olivaceus in Mangrove Forests of Northern Vietnam, The Journal of Animal and Plant Sciences, Vol. 32, No. 3, 2022, pp. 845–854, https://doi.org/10.36899/JAPS.2022.3.0485.