Natural markers (δ13C and δ18O stable isotopes) in the cuttlebones of the European common cuttlefish (Sepia officinalis) were determined for individuals collected across a substantial portion of their range in the Northeast Atlantic Ocean (NEAO) and Mediterranean Sea. Cuttlebone δ13C and δ18O were quantified for core and edge material to characterize geochemical signatures associated with early (juvenile) and recent (sub-adult/adult) life-history periods, respectively. Regional shifts in cuttlebone δ13C and δ18O values were detected across the 12 sites investigated. Individuals collected from sites in the NEAO displayed more enriched δ13C and δ18O values relative to sites in the Mediterranean Sea, with the latter also showing salient differences in both markers among western, central and eastern collection areas. Classification success based on cuttlebone δ13C and δ18O values to four geographical regions (NEAO, western, central and eastern Mediterranean Sea) was relatively high, suggesting that environmental conditions in each region were distinct and produced area-specific geochemical signatures on the cuttlebones of S. officinalis. A modified δ13C and δ18O baseline was developed from sites proximal to the Strait of Gibraltar in both the NEAO and Mediterranean Sea to assess potential mixing through this corridor. Nearly, all (95%) of δ13C and δ18O signatures of S. officinalis collected in the area of the NEAO closest to the Strait of Gibraltar (Gulf of Cadiz) matched the signatures of specimens collected in the western Mediterranean, signifying potential movement and mixing of individuals through this passageway. This study extends the current application of these geochemical markers for assessing the natal origin and population connectivity of this species and potentially other taxa that inhabit this geographical area.

中文翻译：

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天然地球化学标记揭示大西洋和地中海常见墨鱼的环境历史和种群连通性

对于在东北大西洋 (NEAO) 和地中海的大部分范围内收集的个体，确定了欧洲普通墨鱼 (Sepia officinalis) 墨鱼骨中的天然标记物（δ13C 和 δ18O 稳定同位素）。对核心和边缘材料的墨鱼骨 δ13C 和 δ18O 进行量化，以分别表征与早期（幼年）和近期（亚成体/成体）生活史时期相关的地球化学特征。在调查的 12 个地点中检测到墨鱼骨 δ13C 和 δ18O 值的区域变化。相对于地中海的站点，从 NEAO 站点收集的个体显示出更丰富的 δ13C 和 δ18O 值，后者在西部、中部和东部收集区的两个标记上也显示出显着差异。基于墨鱼骨 δ13C 和 δ18O 值对四个地理区域（NEAO、地中海西部、中部和东部）的分类成功率相对较高，表明每个区域的环境条件不同，并在 S. 的墨鱼骨上产生了区域特定的地球化学特征。厚朴。修改后的 δ13C 和 δ18O 基线是从 NEAO 和地中海直布罗陀海峡附近的地点开发的，以评估通过该走廊的潜在混合。在最靠近直布罗陀海峡（加的斯湾）的 NEAO 地区收集的 S. officinalis 的 δ13C 和 δ18O 特征几乎所有（95%）都与在西地中海收集的标本的特征相匹配，表明潜在的运动和混合通过这条通道的个人。