基于碳氮稳定同位素的西北印度洋鸢乌贼摄食习性研究

FEEDING ECOLOGY OF STHENOTEUTHIS OUALANIENSIS BASED ON CARBON AND NITROGEN STABLE ISOTOPE ANALYSIS IN THE NORTHWEST INDIAN OCEAN

内壳是头足类重要的硬组织器官之一,鸢乌贼(Sthenoteuthis oualaniensis)内壳的生长具有不可逆性,是记录鸢乌贼整个生活史信息的良好载体。根据2019年3~5月中国灯光罩网渔船在西北印度洋生产调查期间采集的鸢乌贼样本,利用碳氮稳定同位素技术,研究了个体间的营养生态位关系、摄食习性等。结果表明,雌、雄鸢乌贼个体的内壳δ^(13)C不存在显著性差异(P>0.05),而δ^(15)N存在显著性差异(P<0.05)。营养生态位结果显示,雄性群体的生态位宽幅比雌性群体的要大。雌、雄个体的内壳生长对δ^(13)C均没有显著影响(P>0.05),但雌、雄个体的内壳生长对δ^(15)N均有显著影响(P<0.05),δ^(13)C(1.28‰)和δ^(15)N(3.46‰)值的变化表明鸢乌贼在生长过程中存在洄游现象,营养等级发生改变,且同时期的雌性个体较雄性个体捕食营养层级更高的食物。

Gladius is one of the most important hard tissues of cephalopods.The gladius is a good carrier for recording the whole life history of Sthenoteuthis oualaniensis.S.oualaniensis samples were collected by Chinese light falling-net fishery in March to May 2019 in the northwest Indian Ocean,from which the trophic niche and feeding ecology of S.oualaniensis were studied using stable isotope technology.Results showed that no significant difference inδ^(13)C between female and male individuals with gladius length(P>0.05),butδ^(15)N of male individuals had significant differences with gladius length(P<0.05).The gladius growth of both males and females had no significant relation withδ^(13)C content(P>0.05),but a significant relation withδ^(15)N(P<0.05).The changes inδ^(13)C(1.28‰)andδ^(15)N(3.46‰)indicate a migratory phenomenon that the migration and trophic level of S.oualaniensis were improved as it grew.Furthermore,the females were in a higher trophic level than males.