School of Energy and Environment and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon, Hong Kong, China.
Research Centre for the Oceans and Human Health, City University of Hong Kong Shenzhen Research Institute, Shenzhen, 518057, China.
Sci Rep. 2023 Mar 9;13(1):3976. doi: 10.1038/s41598-023-31174-x.
Understanding the diversity of life history, life stage connectivity and population is essential to determine the spatial scale over which fish populations operate. Otolith microchemistry analysis is a powerful tool to elucidate the life history and population connectivity of fish, providing important insights to the natal origin and population structure. In this study, we used laser ablation inductively coupled plasma mass spectrometry to analyze the chemical composition of otoliths throughout the entire lifetime of endangered fourfinger threadfin species, Eleutheronema tetradactylum. We reconstructed the life history of E. tetradactylum from Southern China collected from different locations over a spatial scale of 1200 km. Sr:Ca and Ba:Ca ratios profiles from otolith core-to-edge analysis suggested two contrasting life history patterns. Based on the differences in early life stages, we identified some fish spending their first year in an estuarine environment with subsequent movement to marine coastal systems, while some fish remaining in the coastal systems throughout their entire early life history stages. The non-metric multi-dimensional scaling showed a strong overlap in otolith core elemental composition, indicating a large-scale connectivity in the life history of E. tetradactylum. The immature fish from different natal origins mixed to a large extent when they fed and overwintered in the extensive offshore waters. Clustering of near core chemistry pointed to three possible sources of nursery for the threadfin fish. This study demonstrated the diversity of life history patterns of E. tetradactylum in Southern Chinese waters. Restoration in egg and larvae densities in coastal waters and estuaries may enhance their population abundances.
了解生活史、生活阶段连通性和种群的多样性对于确定鱼类种群运作的空间尺度至关重要。耳石微化学分析是阐明鱼类生活史和种群连通性的有力工具,为鱼类的出生地和种群结构提供了重要的见解。在这项研究中,我们使用激光烧蚀电感耦合等离子体质谱法分析了濒危四指马鲅耳石的整个生命周期的化学成分。我们从中国南方不同地点采集的空间尺度为 1200 公里的濒危四指马鲅重建了生活史。从耳石核心到边缘的 Sr:Ca 和 Ba:Ca 比值分析表明存在两种截然不同的生活史模式。基于早期生活阶段的差异,我们确定了一些鱼类在河口环境中度过第一年,然后迁移到沿海海洋系统,而一些鱼类则在整个早期生活史阶段都留在沿海系统中。非度量多维标度显示了耳石核心元素组成的强烈重叠,表明四指马鲅的生活史具有大规模的连通性。来自不同出生地的未成熟鱼类在广泛的近海水域中觅食和越冬时,很大程度上混合在一起。近核心化学物质的聚类指向三种可能的幼鱼养育场。本研究表明,中国南方水域四指马鲅的生活史模式具有多样性。在沿海和河口水域增加卵和幼虫密度可能会提高它们的种群数量。