Scalloped hammerhead shark, Sphyrna lewini, is considered a generalist predator, showing individual specializations and different trophic levels. This species inhabits both oceanic islands and coastal nursery areas in the eastern tropical Pacific (ETP) Ocean. Existing trophic ecology studies on S. lewini have been focused on stomach contents. This study provides new insights into its foraging preferences, habitat use, and trophic position, using stable isotope analysis (SIA) of muscle tissue. Stable isotope signatures of δ¹³C and δ¹⁵N were determined in S. lewini muscles (n = 29) from the Ecuadorian Pacific in 2013. Trophic position (TP), isotopic niches, and overlap of S. lewini were estimated by sex, age, and maturity stages to infer their dietary habits throughout life stages. SIA revealed complex movement patterns related to sex and age classes of S. lewini, highlighting high degrees of dietary plasticity and habitat use, with a stronger relation to coastal regions than previously reported. This study provides crucial information regarding essential areas and the related migration behavior of S. lewini, with important implications for their conservation and management in the ETP.

扇贝双髻鲨Sphyrna lewini被认为是一种多面手捕食者，表现出个体的特化和不同的营养水平。该物种栖息在东热带太平洋 (ETP) 海洋的海洋岛屿和沿海育苗区。现有的S. lewini营养生态学研究集中在胃内容物上。这项研究使用肌肉组织的稳定同位素分析 (SIA)，为其觅食偏好、栖息地利用和营养位置提供了新的见解。 2013 年在厄瓜多尔太平洋的S. lewini肌肉 ( n = 29)中确定了 δ ¹³ C 和 δ ¹⁵ N 的稳定同位素特征。营养位置 (TP)、同位素生态位和重叠S. lewini通过性别、年龄和成熟阶段进行估计，以推断其整个生命阶段的饮食习惯。SIA 揭示了与S. lewini 的性别和年龄等级相关的复杂运动模式，突出了高度的饮食可塑性和栖息地利用，与沿海地区的关系比以前报告的要强。这项研究提供了关于S. lewini 的重要区域和相关迁移行为的重要信息，对它们在 ETP 中的保护和管理具有重要意义。