AUTHOR=Hsu Kui-Ching , Yi Mu-Rong , Gu Sui , He Xiong-Bo , Luo Zhi-Sen , Kang Bin , Lin Hung-Du , Yan Yun-Rong TITLE=Composition, Demographic History, and Population Structures of Trichiurus JOURNAL=Frontiers in Marine Science VOLUME=Volume 9 - 2022 YEAR=2022 URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2022.875042 DOI=10.3389/fmars.2022.875042 ISSN=2296-7745 ABSTRACT=Sequences of the complete mitochondrial cytochrome oxidase subunit I gene were used to identify Trichiurus species and examine their population genetic structure and demographic history along the coast of China. Three Trichiurus species were found. Trichiurus japonicus occurs in colder waters along the continental shelves in all the China Seas, T. nanhaiensis prefers warmer waters along continental slopes in the South China Sea, and T. brevis prefers shallow and warmer waters in the South China Sea. The migrations of these species were mainly associated with feeding and spawning preferences. Two major wintering and spawning grounds in the East China Sea and South China Sea were found. All species showed a lack of population genetic structure resulting from their oceanodromous life cycle (the degree of population substructure index NST = 0.000–0.149), but the results of approximate Bayesian computational approaches suggested population declines or stabilization as well as differentiation. The results of the TMRCA (time to the most recent common ancestor) supported that during glaciations, the Yellow Sea and East China Sea were completely exposed, and the South China Sea acted as a refugium. Thus, the populations of these three species experienced differentiation during glaciations. This study also examined the limitations of Bayesian skyline plot analysis.