Gut contents of Pacific saury Cololabis saira during their feeding migration through a transition zone between subtropical and subarctic waters in the North Pacific Ocean are reported. Geographic changes in feeding habits and preferences are described for the months of June and July, for the years 2012, 2016, and 2017. Pacific saury prey comprised 27 taxa. Cluster analysis based on numerical abundance of these prey taxa in guts indicated six Pacific saury feeding types (A to F) existed. Of these, types A–E occurred in low sea surface temperature waters (<ca 14°C). Gut content weight and gut fullness index were greater in types A, B, and E, with copepods Neocalanus plumchrus/flemingeri and/or N. cristatus contributing highly to carbon‐base weight. Although small euphausiids occurred in guts, guts were also often empty, suggesting feeding was less active at higher sea surface temperatures (>ca 14°C). Feeding patterns reveal N. plumchrus/flemingeri tended to be important prey species in areas west of ca 175°E, whereas Pacific saury feed mainly and selectively on N. cristatus in eastern areas, indicating a longitudinal difference in the trophic pathway from zooplankton prey to Pacific saury. These spatial differences in trophic pathways improve our understanding of nutritional intake in the commercially important Pacific saury during its feeding migration, and the effects this might have on fish size and weight, and associated commercial value.

中文翻译：

---

北太平洋洋中秋刀鱼科拉毕斯（Colabis）的进食地理变化

据报道，太平洋秋刀鱼科拉毕比赛拉通过北太平洋亚热带和亚北极水域之间的过渡带进食时的肠内容物。描述了2012年，2016年和2017年6月和7月的喂养习惯和偏好的地理变化。太平洋秋刀鱼猎物包括27个分类单元。基于这些猎物类群在肠道中的数量丰富的聚类分析表明，存在六种太平洋秋刀鱼的进食类型（A到F）。其中，AE型发生在海表温度较低的水域（<ca 14°C）。A，B和E型co足动物的肠道含量重量和肠饱满度指数更高Neocalanus plumchrus / flemingeri和/或N. cristatus对碳基重量有很大贡献。尽管肠道中出现少量的肠胃上皮炎，但是肠道也常常是空的，这表明在较高的海面温度（> ca 14°C）下进食活动较少。取食方式表明，羽扇豆/弗兰门格里猪笼草在约175°E以西地区是重要的猎物种类，而秋刀鱼则主要和选择性地在猪笼草上捕食。在东部地区，表明从浮游生物猎物到秋刀鱼的营养路径在纵向上存在差异。营养路径的这些空间差异增进了我们对商业上重要的秋刀鱼进食过程中营养摄入的理解，以及这可能对鱼的大小和体重以及相关的商业价值产生影响。