西北太平洋公海柔鱼和日本爪乌贼个体发育期营养生态位变化分析OA北大核心CSTPCD

In order to better understand the nutritional niche changes during the ontogeny period of Ommastrephes bartramii and Onychoteuthis borealijaponicus,36 O.bartramii and 30 O.borealijaponicus samples were collected from"Songhang"fishery resources survey ship in 2021-2022,and stable isotopic analysis was conducted on their eye crystals.The results show that:the variation in individual δ13C and δ15N values for O.bartramii ranged from 0.10‰ to 1.68‰ and 0.79‰ to 7.51‰,respectively;and the variation in individual δ13C and δ15N values for O.borealijaponicus ranged from 0.15‰ to 1.20‰ and 0.81‰ to 7.05‰,respectively.The niche area change range for O.bartramii and O.borealijaponicus was 0.40‰2-5.85‰2 and 0.27‰2-5.36‰2,respectively.GAM model analysis showed that the δ13C and δ15N values of O.bartramii eye crystals had a significant correlation with crystal diameter,with deviation interpretation rates of 31.9％and 34.3％,respectively.Similarly,the δ13C and δ15N values of O.borealijaponicus eye crystals were significantly correlated with crystal diameter,with deviation interpretation rates of 12.9％and 19.4％,respectively.According to the analysis,O.bartramii and O.borealijaponicus feeding flexibility is responsible for the irregular change of δ13C and δ15N values with increasing carcass size.The larger magnitude of individual isotopic changes reflects the greater magnitude of baseline isotopic values in the Kuroshio-Oyashio transition zone in Northwest Pacific Ocean.Additional 83％of the O.bartramii samples and 80％of the O.borealijaponicus samples niche amplitude of δ13C was small,but niche amplitude of δ15N was larger,so the feeding level of O.bartramii and O.borealijaponicus in this area is different.The GAM model showed that individual growth and baseline values were factors affecting the tissue δ13C and δ15N values.