International Journal of Aquaculture, 2025, Vol.15, No.3, 116-134 http://www.aquapublisher.com/index.php/ija 116 Research Insight Open Access Research on Phylogenesis and Species Definition of Oxyeleotris marmoratus Based on Mitochondrial Genome Linhua Zhang, Lingfei Jin Aquatic Biology Research Center, Cuixi Academy of Biotechnology, Zhuji, 311800, Zhejiang, China Corresponding authors: lingfei.jin@jcat.org International Journal of Aquaculture, 2025, Vol.15, No.3 doi: 10.5376/ija.2025.15.0012 Received: 03 May., 2025 Accepted: 08 Jun., 2025 Published: 18 Jun., 2025 Copyright © 2025 Zhang and Jin, This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Preferred citation for this article: Zhang L.H., and Jin L.F., 2025, Research on phylogenesis and species definition of Oxyeleotris marmoratus based on mitochondrial genome, International Journal of Aquaculture, 15(3): 116-134 (doi: 10.5376/ija.2025.15.0012) Abstract Marble goby (Oxyeleotris marmorata) is a freshwater fish with high economic value in aquaculture and widespread distribution in Southeast Asia. In this study, phylogenetic analysis of marble goby and related groups was performed using mitochondrial genome data from previous studies, and molecular population genetics was used to explore their species boundaries. Many results showed that the mitochondrial genome of marble goby is about 16.5 kb in length, encoding 13 protein genes, 22 tRNA genes and 2 rRNAgenes, and the gene structure is consistent with that of typical bony fish. The phylogenetic tree shows that marble goby belongs to the family Channidae of the suborder Goby in fish classification, and is clearly differentiated from closely related groups such as the family Oxyeleotris (mudskippers, etc.) and the family Goby. The mitochondrial genetic differences between different geographical populations within the species are low (for example, the COI genetic distance between the artificially cultured population and the wild population is only 0.66%), but obvious genetic differentiation is still observed between the large river basins, suggesting the possible existence of cryptic lineages. Closely related species that are difficult to distinguish by morphological identification can be identified by molecular data. Species delimitation analysis based on mitochondrial sequences supports that the marble goby is a single species, but it is recommended to combine nuclear genome data for comprehensive taxonomic verification. This study emphasizes the importance of combining morphological characteristics with molecular evidence for species delimitation, and puts forward conservation and management recommendations for the phylogeographic pattern of marble goby in the Mekong region. The research results provide a scientific basis for fish taxonomy, species conservation and aquaculture breeding. Keywords Marble goby; Mitochondrial genome; Phylogeny; Species delimitation; Comprehensive taxonomy 1 Introduction In Southeast Asia, when it comes to a freshwater fish with delicate meat and popular in the market, many people's first reaction is the marble goby, also known as the Oxyeleotris marmorata. This fish was introduced to southern my country for breeding at the end of the last century because it grows slowly but is particularly popular. Gradually, it has settled in some places and has become an alien fish species that may affect the local ecology (Wantania et al., 2025). However, marble goby is not just as simple as "delicious". It is not small in size and is a typical ambush predator. It may be an "invisible killer" for local small fish and small invertebrates in the water. Its arrival may indeed disrupt the original ecological balance, especially in some waters with high biodiversity. From the perspective of breeding, it is a high-value "star fish species". Breeding, reproduction, and improving survival rates have always been the focus of attention in the industry. And understanding its population structure and genetic background can help farmers select better strains and avoid the problem of "gene degeneration" caused by inbreeding. Having said that, the genus Oxyeleotris to which the marble goby belongs is not a "lonely" guy. There are quite a lot of species in this genus, with about 17 species worldwide, of which 8 are concentrated in Southeast Asia such as Indonesia (Syaifudin et al., 2021). These fish not only look alike, but also have a lot of overlap in their range of activities, which often makes traditional classification methods "headache". Therefore, the marble goby, the most widely distributed representative species, is actually quite representative in the study of species evolution and adaptation mechanisms of freshwater fish. By the way, it has been introduced before - for example, it was introduced to Taiwan in the 1970s and brought to mainland China in the 1980s for aquaculture.
RkJQdWJsaXNoZXIy MjQ4ODYzNA==