Assessing Larval Fish Diversity and Conservation Needs in the Luzon Strait using DNA Barcoding

Accurate species identification and biodiversity assessment of larval fish are essential for effective management and conservation of fisheries resources, as it allows for the estimation of parent stocks, assessment of future recruitment, and prediction of spawning and nursing grounds. However, traditional morphology-based identification methods have inherent limitations, highlighting the need for accurate and efficient techniques to address these challenges effectively. The Luzon Strait, a crucial channel connecting the South China Sea to Western Pacific Ocean, is renowned for its fish biodiversity. However, our knowledge of the biodiversity status of larval fish species in this region remains insufficient. Here we employed DNA barcoding to assess larval fish species diversity in the Luzon Strait and adjacent waters. A total of 385 larval fish individuals were collected from 15 stations, and 354 individuals were successfully barcoded and identified, representing 147 species from 93 genera, 44 families, and 22 orders. The interspecific K2P divergence exhibited a significant increase of approximately 55-fold higher than intraspecific divergence. The phylogenetic neighbor-joining tree confirmed the distinct lineages for each taxonomic level, demonstrating the feasibility of DNA barcoding. We observed notable variations in fish species diversity and community composition among sampling stations. Non-metric multidimensional scaling analysis revealed greater diversity and dissimilarity of larval fish community compositions in the western regions compared to the eastern regions. This pattern corresponded to the grouping based on the path of the Kuroshio current, suggesting its influence on the fish community structure. Additionally, economically valuable species were identified at these stations, highlighting their ecological significance as potential spawning or nursery grounds for larval fish. We also examined the habitat type, human use, and conservation status of each larval fish species, providing comprehensive insights into their ecological significance and conservation needs. This study offers valuable information for identifying important spawning and nursing grounds of fish populations, thereby supporting sustainable management and conservation of fisheries resources in this region.

精准鉴定鱼类幼体物种并开展生物多样性评估，对于渔业资源的有效管理与保护至关重要——此类工作可用于估算亲本种群、评估未来资源补充量，以及预测鱼类产卵场与育幼场。然而，传统基于形态学的物种鉴定方法存在固有局限，亟需精准高效的技术手段以有效应对上述挑战。
吕宋海峡作为连接南海与西太平洋的关键通道，以其丰富的鱼类生物多样性闻名于世，但当前学界对该区域鱼类幼体物种的生物多样性现状仍认知不足。本研究采用DNA条形码（DNA barcoding）技术，对吕宋海峡及其邻近海域的鱼类幼体物种多样性展开系统性评估。
研究共在15个采样站位采集到385尾鱼类幼体样本，其中354尾成功完成条形码测序与物种鉴定，隶属于22目、44科、93属，共计147个物种。
分析显示，种间Kimura二参数（K2P）分歧度较种内分歧度提升约55倍，差异具有统计学显著性。通过邻接系统发育树分析，各分类阶元均形成独立演化支系，验证了DNA条形码技术在该研究中的可行性。
研究发现，不同采样站位的鱼类物种多样性与群落组成存在显著差异。
非度量多维标度（Non-metric Multidimensional Scaling, NMDS）分析结果表明，西部海域的鱼类幼体群落组成多样性与物种异质性均高于东部海域。该分布模式与基于黑潮路径的分组结果高度吻合，提示黑潮对该区域鱼类群落结构具有显著调控作用。
此外，本研究在各站位还鉴定出兼具经济价值的鱼类物种，进一步印证了吕宋海峡及其邻近海域作为鱼类幼体潜在产卵场或育幼场的核心生态意义。
本研究同时梳理了各鱼类幼体物种的栖息生境类型、人类利用方式与保护现状，为其生态意义解读与针对性保护需求分析提供了全面的科学视角。
本研究为识别鱼类种群关键产卵场与育幼场提供了宝贵的数据支撑，可为该区域渔业资源的可持续管理与保护工作提供重要决策依据。