基于稳定同位素的江苏近海金乌贼摄食生态研究

为进一步掌握江苏近海金乌贼(Sepia esculenta)种群生活史特征，根据在江苏沿海港口所采集的样本，利用碳氮稳定同位素分析法对金乌贼的摄食生态及营养生态位进行了研究。结果表明，金乌贼雌、雄群体间 13C和 15N值均不存在显著性差异；金乌贼的 值与胴长之间相关性不显著， 值与胴长之间存在显著相关性；雄性金乌贼营养生态位宽度（SEAc=0.57‰2）与雌性（SEAc=0.63‰2）无明显差异，雌性略大于雄性，且两者高度重叠（0.62）。同位素聚类分析显示，可将金乌贼个体分为75~114mm、115~184mm和185~204mm三个胴长组；185~204mm胴长组营养生态位宽度最大（SEAc=1.77‰2），75~114mm胴长组营养生态位宽度最小（SEAc=0.39‰2）；仅75~114mm和115~184mm胴长组间生态位重叠率为中度重叠（0.34），其余胴长组间生态位重叠率低。分析认为，金乌贼δ13C值的变化主要受同位素基线值和金乌贼洄游模式影响，而δ15N值的变化主要受金乌贼摄食作用影响；雌性和雄性金乌贼群体之间食物资源和栖息地利用高度相似；不同发育阶段的金乌贼在营养生态位上具有明显差异。

Feeding ecology of Sepia esculenta in Jiangsu coastal waters based on stable isotopes analysis

In order to further understand the characteristics of the life history of the Sepia esculenta population in the coastal waters of Jiangsu, the feeding ecology and nutritional niche of the Sepia esculenta were studied by using the carbon and nitrogen stable isotope analysis method based on the samples collected in the coastal ports of Jiangsu. The results showed that there was no significant difference in δ13C and δ15N values between male and female populations of Sepia esculenta (P>0.05, P>0.05); There was a significant correlation between them (PC>0.05; PN<0.05); the nutritional niche width of male Sepia esculenta (SEAc=0.57‰2) was not significantly different from that of females (SEAc=0.63‰2), and females were slightly larger than males, and both are highly overlapping (0.62). Isotopic cluster analysis showed that Sepia esculenta individuals could be divided into three carcass length groups of 75~114mm, 115~184mm and 185~204mm; The niche width of the 114mm carcass length group was the smallest (SEAc=0.39‰2); only the niche overlap rate between the 75~114mm and 115~184mm carcass length groups was moderate (0.34), and the niche overlap rate among the other carcass length groups was low. According to the analysis, the change of δ13C value of Sepia esculenta is mainly affected by the isotope baseline value and the migration pattern of Sepia esculenta, while the change of δ15N value is mainly affected by the feeding effect of Sepia esculenta; the height of food resources and habitat utilization between female and male goldensquid groups Similar; Sepia esculenta at different developmental stages had obvious differences in nutritional niche.