Abstract Phenotypic variation in fish can indicate exposure to different environmental conditions, affecting species growth and maturation rates and/or be a consequence of genetic factors that allow fish adaptation to different environments. Understanding population structure and dynamics is extremely important for the establishment of sustainable fisheries. The blue jack mackerel, Trachurus picturatus, is an important fishery resource of the North-East (NE) Atlantic. Fish were captured in six sampling locations in the NE Atlantic - Azores, Madeira, Canaries and Portugal mainland - Matosinhos, Peniche and Portimao. The phenotypic diversity of the species was studied using body landmark-based geometric morphometrics. A truss box method was followed and 30 distance variables were extracted from digital images. Additionally, the temporal stability of the morphological characters was investigated by comparing samples from two different years: 2016 and 2019. The transformed distances were analysed by univariate and multivariate statistics. The Macaronesia region – Azores, Madeira and Canaries – and Portugal mainland displayed a clear phenotypic pattern. Distances related to the body width and caudal peduncle were the most significant variables explaining the observed phenotypic heterogeneity. Furthermore, this study also showed that T. picturatus can exhibit fast phenotypic adaptations to the surrounding environment, observed by the discrimination of Peniche in 2019. Nevertheless, the high overall allocation of individuals to the original location observed for both years (78% in 2016 and 83% in 2019) suggests that the population of T. picturatus in the NE Atlantic is phenotypic heterogeneous. These findings corroborate previous studies and have implications for fishery management.

中文翻译：

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基于地标的几何形态计量学分析来自东北大西洋的蓝鲭鱼种群之间的体型变化，Trachurus picturatus

摘要 鱼类的表型变异可以表明暴露于不同的环境条件，影响物种的生长和成熟率和/或是遗传因素使鱼类适应不同环境的结果。了解种群结构和动态对于建立可持续渔业极为重要。蓝鲭鱼 Trachurus picturatus 是东北 (NE) 大西洋的重要渔业资源。鱼类是在大西洋东北部的六个采样地点捕获的 - 亚速尔群岛、马德拉群岛、加那利群岛和葡萄牙大陆 - Matosinhos、Peniche 和 Portimao。使用基于身体标志的几何形态测量学研究了该物种的表型多样性。遵循桁架箱方法，从数字图像中提取 30 个距离变量。此外，通过比较两个不同年份的样本来研究形态特征的时间稳定性：2016 年和 2019 年。通过单变量和多变量统计分析转换后的距离。马卡罗尼西亚地区——亚速尔群岛、马德拉群岛和加那利群岛——以及葡萄牙大陆显示出清晰的表型模式。与体宽和尾柄相关的距离是解释观察到的表型异质性的最重要变量。此外，这项研究还表明，T. picturatus 可以表现出对周围环境的快速表型适应，这是通过 2019 年对 Peniche 的歧视观察到的。 尽管如此，这两年观察到的个体对原始位置的总体分配较高（2016 年为 78% 2019 年为 83%）表明 T. 东北大西洋的 picturatus 是表型异质的。这些发现证实了以前的研究，并对渔业管理有影响。