| 摘要: |
| 秋刀鱼（Cololabis saira）广泛分布于西北太平洋海域，是我国重要的大洋性远洋作业对象之一。为研究秋刀鱼摄食以及营养生态位特征，基于2018年7~11月西北太平洋公海采集的秋刀鱼样本，分析了秋刀鱼肌肉样本的碳、氮稳定同位素特征。结果表明：（1）样本碳稳定同位素（δ13C）值范围在-24.60‰~-20.69‰之间，氮稳定同位素（δ15N）值范围在6.49‰~11.11‰之间，以桡足类作为基线生物，营养级范围在2.44~3.71之间。（2）雌雄样本间δ13C值、δ15N值、营养级均不存在显著性差异（P>0.05）；雄性样本核心生态位（SEAc）和总生态位（TA）均高于雌性。（3）广义相加模型（Generalized Additive Model，GAM）显示，δ13C值、δ15N值和营养级值均随体长增加而增大（P<0.05）；251~260 mm体长组间的SEAc高于其他体长组；聚类分析结果表明，体长小于280 mm和大于280 mm的样本δ13C值、δ15N值均存在显著性差异（P<0.05）。（4）亲潮延伸区海域和西北亚北极环流海域样本的δ13C值、δ15N值均存在显著性差异（P<0.05），且亲潮延伸区海域的δ13C值、δ15N值和营养级值均高于西北亚北极环流海域，亲潮延伸区海域的SEAc和TA均低于西北亚北极环流海域。综上表明，不同生活史阶段、栖息海域均可影响秋刀鱼摄食，研究结果可为西北太平洋公海秋刀鱼的摄食生态研究提供参考。 |
| 关键词: 营养级 秋刀鱼 δ13C δ15N 西北太平洋 |
| DOI：10.11693/hyhz20220700189 |
| 分类号: |
| 基金项目:国家重点研发计划课题，2020YFD0901203号；浙江省2022年“领雁”研发攻关计划项目，2022C02025号。 |
|
| CHARACTERISTICS OF CARBON AND NITROGEN STABLE ISOTOPE OF PACIFIC SAURY IN THE NORTHWEST PACIFIC HIGH SEAS |
|
YANG Na1, HUA Chuan-Xiang1,2,3,4, ZHU Qing-Cheng1,2,3,4, HU Guan-Yu1,2,3,4, LIANG Jia-Wei1
|
|
1.College of Marine Science, Shanghai Ocean University, shanghai 201306, China;2.National Distant-water Fisheries Engineering Research Center, Shanghai Ocean University, Shanghai 201306, China;3.Key Laboratory of Sustainable Exploitation of Oceanic Fisheries Resources, Ministry of Education;4.Shanghai Ocean University, Shanghai 201306, China
|
| Abstract: |
| The Pacific saury Cololabis saira is widely distributed in the northwestern Pacific Ocean and is one of the important pelagic objects in China. The carbon and nitrogen stable isotope characteristics of muscle samples of Pacific saury from July to November 2018 in the high seas of the Northwest Pacific Ocean were analyzed. Results showed that the δ13C values of samples ranged from -24.60‰ to -20.69‰, on average of -21.74‰; the δ15N values from 6.49‰ to 11.11‰ on average of 8.51‰; and the trophic levels ranged 2.44~3.71 with copepods as the baseline. There were no significant differences between males and females (P>0.05) in δ13C value, δ15N value, and trophic level. Both the core niche indicator SEAc (Standard Ellipse Area (SEA):the standard elliptical area enclosed by all points in the scatter chart, and SEAc is the corrected SEA) and the total niche indicator TA (Total Area of Convex Hull (TA):the convex polygon area enclosed by the outermost points in the scatter chart) of male samples were higher than those of females' but with an overlap of SEAc between males and females, indicating competition for food between males and females. In addition, δ13C,δ15N, and trophic level values increased with body length as shown in the analysis of generalized additive models. Specifically, the SEAc of 251~260 mm body-length group was higher than that of other body-length groups. The Pacific saury could be clearly separated into two groups at 280 mm in body length as shown in the clustering analysis. Moreover, there were significant differences in δ13C and δ15N values between Oyashio Extension (OE) area and Western Subarctic Gyre (WSG) area (P<0.05), and δ13C, δ15N, and trophic level values in OE were higher than those in WSG. Both SEAc and TA in OE were lower than those in WSG. Therefore, different life stages and habitats can affect the feeding ecology of Pacific saury. This research provided a reference for the ecological study of Pacific saury in the high seas of northwest Pacific Ocean. |
| Key words: trophic level Pacific saury δ13C δ15N northwest Pacific Ocean |
