Meroplankton diversity, seasonality and life-history traits across the Barents Sea Polar Front revealed by high-throughput DNA barcoding

In many species of marine benthic invertebrates, a planktonic larval phase plays a critical role in dispersal. Very little is known about the larval biology of most species, however, in part because species identification has historically been hindered by the microscopic size and morphological similarity among related taxa. This study aimed to determine the taxonomic composition and seasonal distribution of meroplankton in the Barents Sea, across the Polar Front. We collected meroplankton during five time points seasonally and used high-throughput DNA barcoding of individual larvae to obtain species-level information on larval seasonality. We found that meroplankton was highly diverse (72 taxa from eight phyla) and present in the Barents Sea year-round with a peak in abundance in August and November, defying the conventional wisdom that peak abundance would coincide with the spring phytoplankton bloom. Ophiuroids, bivalves and polychaetes dominated larval abundance while gastropods and ...在许多海洋底栖无脊椎动物类群中，浮游幼虫阶段在物种扩散过程中发挥着关键作用。然而，目前对多数物种的幼虫生物学特性所知甚少，部分原因在于长期以来，近缘类群（taxa）的物种鉴定因幼虫体型微小、形态相似而受阻。本研究旨在解析巴伦支海（Barents Sea）跨极锋（Polar Front）海域的暂时性浮游生物（meroplankton）类群组成与季节分布格局。研究团队按季节设置5个采样时间点采集暂时性浮游生物样本，并通过对单条幼虫进行高通量DNA条形码（DNA barcoding）分析，获取了幼虫季节动态的物种级信息。研究结果显示，巴伦支海的暂时性浮游生物多样性极高（涵盖8个门、72个分类群），且全年均有分布，其丰度峰值出现在8月与11月，这与“丰度峰值与春季浮游植物水华（phytoplankton bloom）同步”的传统认知相悖。蛇尾类（ophiuroids）、双壳类（bivalves）与多毛类（polychaetes）在幼虫丰度中占据主导地位，而腹足类（gastropods）及……