Dispersal is a key process shaping species population structure. In demersal marine fishes, which usually have sedentary adult phases, dispersion relies on drifting larval stages. However, the dynamics and seasonal variability of seawater masses can greatly determine the connectivity patterns of these species along the same geographic gradient. For this reason, detailed information on the release moment of larvae is needed to obtain accurate patterns of connectivity. In this study, we performed backtracking Lagrangian particle dispersion simulations, with individual-based early life traits data, obtained from otolith reading for 1413 juveniles of nine fish species belonging to three families (Sparidae, Pomacentridae and Labridae). For each species, individuals had been sampled from four to seven localities in the western Mediterranean Sea between the Gulf of Lion to the Gibraltar Strait. These nine species reproduce in different seasons of the year and their pelagic larval duration (PLD) range from 7 to 43 days. We identified three hydrodynamic units separated by oceanographic discontinuities (Balearic Sea, West Algerian Basin and Alboran Sea) with low settler’s exchange according to our simulations, independently of the PLD and reproductive season of the species. Hatching date and PLD showed significant effects on larval dispersal distance and orientation, both at the intraspecific and interspecific levels, highlighting the importance of these variables in determining the geographic origin of individuals. Our multispecies modelling approach adds a step forward for an accurate description of larval dispersion and recruitment, key to understand population resilience and define management strategies.

分散是塑造物种种群结构的关键过程。在通常具有久坐成年期的海底鱼类中，扩散依赖于漂移的幼体期。但是，海水团块的动力学和季节性变化可以极大地决定这些物种沿相同地理梯度的连通性模式。因此，需要有关幼虫释放时刻的详细信息以获得准确的连接方式。在这项研究中，我们使用基于个体的早期生命特征数据对拉格朗日粒子分散度进行了回溯，这些数据是从耳石读取的9种1314种鱼类（Spa科，P科和唇科）的耳石读取的。对于每个物种，在地中海南部的狮子湾至直布罗陀海峡之间的四个至七个地点取样了个体。这九种物种在一年中的不同季节繁殖，其上层幼体持续时间（PLD）为7至43天。根据我们的模拟，我们确定了三个海洋动力单元，这些海洋动力单元被海洋不连续性隔开（巴利阿里海，阿尔及利亚西部盆地和阿尔伯兰海），定居者的交换率较低，而与该物种的PLD和繁殖季节无关。孵化日期和PLD在种内和种间水平上均对幼虫传播距离和方向产生了显着影响，突显了这些变量在确定个体地理起源方面的重要性。