基于碳、氮稳定同位素研究胶州湾普氏栉虾虎鱼的摄食习性

Feeding habits of Rhinogobius pflaumi in Jiaozhou Bay,China based on carbon and nitrogen stable isotope analysis

普氏栉虾虎鱼属于小型暖温性底层鱼类,是胶州湾鱼类群落中的优势种之一,在胶州湾食物网和生态系统中发挥着重要作用.本文应用碳、氮稳定同位素技术,基于胶州湾渔业资源底拖网调查采集的样品,对普氏栉虾虎鱼的摄食习性进行了研究.结果表明:胶州湾普氏栉虾虎鱼的δ15N值范围为11.24‰~13.99‰,平均值为(12.70±0.70)‰,δ^(13_C值范围为-20.67‰^-18.46‰,平均值为(-19.08±0.36)‰;各体长组的营养级范围为3.49~3.76,平均营养级为(3.62±0.21),其δ^(15)N值和营养级与体长呈显著负相关,δ13C值与体长无显著相关性.普氏栉虾虎鱼摄食的主要饵料生物类群为多毛类、虾类和软体动物,浮游动物和颗粒有机物(POM)的饵料贡献率较小.聚类分析结果表明,普氏栉虾虎鱼各体长组食物组成的相似性均在92%以上,相似性较高,说明其摄食习性随体长变化无明显差异.普氏栉虾虎鱼在胶州湾生态系统中属于中级消费者,其摄食各饵料生物类群比例的变化可能是其营养级与体长呈负相关关系的主要原因.

Rhinogobius pflaumi is a small-sized,warm-temperate demersal fish species. It is one of the dominant species in fish community,and plays an important role in Jiaozhou Bay ecosystem.The trophic level and feeding habits of R. pflaumi were investigated by carbon and nitrogen stable isotope analysis,based on the data collected from the bottom trawl surveys during May 2011 in Jiaozhou Bay,China in this study. The results showed that the δ-（15）N and δ-（13）C values of R. pflaumi ranged from 11.24‰ to 13.99‰ and-20.67‰ to-18.46‰,respectively. The mean values of δ15 N and δ-（13）C were（ 12.70±0.70） ‰ and（-19.08±0.36） ‰,respectively. The mean trophic level of R.pflaumi was（ 3.62±0.21） for all size classes,ranging from 3.49 to 3.76 for different size classes.There was a significant negative correlation between the δ-（15）N values and standard length,while no significant correlation was observed between δ-（13）C values and standard length. The main prey groups of R. pflaumi were polychaeta,decapoda and mollusca. The trophic contributions of zooplankton and particle organic matter（ POM） were relatively low. The similarities of prey species composition among different size classes were more than 92%,indicating that there was no significant difference in feeding habits with different standard lengths. R. pflaumi was an intermediate consumer in Jiaozhou Bay ecosystem. The significant negative correlation between trophic level and standard length might be due to variation in the proportion of different prey groups.