Collichthys lucidus is a eurythermic and euryhaline fish that prefers to live in middle and bottom waters and is widely distributed in the coastal waters of China. In recent years, the situation of C. lucidus resources has not been optimistic due to the overexploitation of fishery resources in offshore waters. In this study, the population structure of C. lucidus in the Haizhou Bay Fishing Ground (HZBFG), Xiangshan Bay Fishing Ground (XSBFG) and Lvsi Fishing Ground (LSFG) in the coastal waters of China was compared based on otolith morphology and microchemistry. The traditional morphological indicators and elliptic Fourier indicators of otoliths showed that there is a significant difference between the HZBFG population and the LSFG population (P < 0.05), and the XSBFG population (P < 0.05), mainly reflected in the differences between basal lobes, wing lobes and main interstitial sulci. The overlap degree of otolith contour between the LSFG and XSBFG populations was higher. The combination mechanism of microchemical elements in otoliths showed that Sr/Ca, Mg/Ca and Ba/Ca of C. lucidus in the otolith core zone was not significant (PERMANOVA, P = 0.051), and that in the otolith edge zone was significantly different (PERMANOVA, P = 0.001). Generally, the LSFG and XSBFG populations probably belong to the same population, while the HZBFG population located in the northern Yellow Sea can be identified as a separated population. We conclude that C. lucidus was distributed in the coastal waters of the East China Sea and the Yellow Sea during the early life period and eventually formed a north–south differentiation pattern through migration after reaching adulthood. This study can be used as a basic reference for the conservation and sustainable utilization of the resources of C. lucidus.

鳅鱼是广温性、广盐性鱼类，喜生活在中底层水域，广泛分布于我国近海。近年来，由于近海渔业资源的过度捕捞，赤鱼资源状况并不乐观。本研究基于耳石形态和微化学特征，对我国近海海州湾渔场（HZBFG）、象山湾渔场（XSBFG）和吕四渔场（LSFG）的赤鱼种群结构进行了比较。耳石传统形态指标和椭圆傅里叶指标显示，HZBFG群体与LSFG群体存在显着差异（P  < 0.05），XSBFG群体差异显着（P  < 0.05），主要体现在基底叶、翼叶和主间质沟。LSFG和XSBFG群体耳石轮廓重叠程度较高。耳石中微量化学元素的结合机制表明，耳石核心区的灵芝Sr/Ca、Mg/Ca、Ba/Ca不显着（PERMANOVA，P  =0.051），耳石边缘区显着不同（PERMANOVA，P  = 0.001）。一般来说，LSFG和XSBFG种群很可能属于同一种群，而位于黄海北部的HZBFG种群则可以确定为不同的种群。我们认为，赤线虫在生命早期分布于东海和黄海沿岸海域，成年后通过迁徙最终形成南北分化格局。该研究可为灵芝资源的保护和可持续利用提供基础参考。