To test whether stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) can be used to understand the ecological connectivity of Japanese flounder Paralichthys olivaceus, we evaluated the isotopic signatures of juvenile P. olivaceus from the Pacific coast of northern Japan (i.e., from Aomori to Ibaraki Prefectures). We measured δ13C and δ15N in muscle and collagen extracted from vertebrae and found that isotope ratios were strongly correlated in both. The discrimination models we developed for muscle and collagen proved useful in distinguishing among juvenile P. olivaceus collected from the five prefectures (Aomori, Iwate, Miyagi, Fukushima, and Ibaraki). Juveniles collected in Aomori in particular showed significantly lower values of δ13C and δ15N than those from the other prefectures, which likely reflects the greater influence of the Tsugaru Warm Current in that region. Because collagen in the vertebral centrum can be used to reconstruct annual isotopic records, our results may also assist in developing migration tracking procedures for adult P. olivaceus along the Pacific coast of northern Japan.

中文翻译：

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基于碳氮稳定同位素比的日本北部太平洋沿岸日本比目鱼幼鱼Paralichthys olivaceus育苗地点的判别

为了测试碳 (δ13C) 和氮 (δ15N) 的稳定同位素比率是否可用于了解日本比目鱼 Paralichthys olivaceus 的生态连通性，我们评估了来自日本北部太平洋沿岸的 P. olivaceus 幼鱼的同位素特征（即，从青森县到茨城县）。我们测量了从椎骨中提取的肌肉和胶原蛋白中的 δ13C 和 δ15N，发现同位素比率在两者中都具有很强的相关性。我们为肌肉和胶原蛋白开发的区分模型被证明可用于区分从五个县（青森县、岩手县、宫城县、福岛县和茨城县）收集的幼鱼。特别是在青森县收集的幼鱼的δ13C和δ15N值明显低于其他县的δ13C和δ15N。这可能反映了津轻暖流对该地区的更大影响。由于椎体中的胶原蛋白可用于重建年度同位素记录，因此我们的结果也可能有助于开发日本北部太平洋沿岸成年 P. olivaceus 的迁移跟踪程序。