White sharks (Carcharodon carcharias) are described as generalist predators, with a demonstrated ontogenetic dietary shift which occurs between subadult and adult life stages. Trophic ecology studies on white shark have been focused mainly on large and mature individuals, necessitating studies of young white shark trophic ecology to better understand their resource use. This study provides new insights into young white shark diet in the North eastern Pacific Ocean using stable isotope analysis in muscle tissues. We analyzed δ¹³C and δ¹⁵N values of young white shark muscle (n = 21) from Sebastian Vizcaino Bay (SBV) during 2015–2018. We found changes in prey composition across early [neonates, young-of-the-years (YOYs), juveniles] white shark life stages, with significant changes in isotopic composition throughout early ontogeny. Mixing model results indicate a high use of coastal areas for foraging, mainly for juvenile stages and the substantial contribution of pelagic preys (e.g., S. japonicus, Prionotus spp., Cynoscion spp., S. sagax, etc.) in YOYs, white shark diet also indicates an important role of offshore foraging. This change in isotopic composition likely represents the shift from the embryo’s typical maternally derived isotopic signature, incorporated in offshore foraging regions, to the postpartum isotopic composition incorporated by foraging neonates in inshore nursery habitats. This study provides relevant information regarding young white shark feeding preferences, reinforces the importance of coastal areas as critical habitat for the development and the successful foraging of this species, and also provides indirect insights on the feeding habits of the adult female of white sharks, which constitutes a baseline for further research.

中文翻译：

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对墨西哥下加利福尼亚半岛附近水域幼白鲨（Carcharodon carcharias）营养生态学的新见解

大白鲨（Carcharodon carcharias）被描述为多面手捕食者，在亚成体和成体生命阶段之间发生了明显的个体发育饮食转变。大白鲨的营养生态学研究主要集中在大型成熟个体上，因此需要对幼鲨的营养生态学进行研究以更好地了解它们的资源利用。这项研究使用肌肉组织中的稳定同位素分析为东北太平洋的年轻白鲨饮食提供了新的见解。我们分析了 2015-2018 年来自塞巴斯蒂安比斯卡诺湾 (SBV) 的年轻白鲨肌肉 (n = 21) 的 δ¹³C 和 δ¹⁵N 值。我们发现早期 [新生儿、幼年 (YOY)、少年] 白鲨生命阶段的猎物组成发生了变化，在整个早期个体发育过程中同位素组成发生了显着变化。混合模型结果表明沿海地区大量用于觅食，主要用于幼鱼阶段和远洋猎物（例如 S. japonicus、Prionotus spp.、Cynoscion spp.、S. sagax 等）在 YOYs、white鲨鱼饮食也表明近海觅食的重要作用。同位素组成的这种变化可能代表了从胚胎的典型母体衍生同位素特征（结合在近海觅食区）到产后在近海育苗栖息地觅食的新生儿所结合的同位素组成的转变。这项研究提供了有关幼鲨进食偏好的相关信息，强调了沿海地区作为该物种发展和成功觅食的关键栖息地的重要性，