脂肪酸对中华哲水蚤摄食两种海洋微藻的指示作用  

Identification of trophic relationships between marine algae and the copepod Calanus sinicus in a fatty acid approach

作　　者：刘梦坛[1,2] 李超伦[1,3] 孙松[1,3] 

机构地区：[1]中国科学院海洋研究所海洋生态与环境科学重点实验室,青岛266071 [2]中国科学院研究生院,北京100049 [3]山东胶州湾海洋生态系统国家野外科学观测研究站,青岛266071

出　　处：《生态学报》2011年第4期933-942,共10页Acta Ecologica Sinica

基　　金：国家自然科学基金资助项目(40776092;40631008;40821004);IPY中国行动计划

摘　　要：在室内以饥饿培养为对照,以海洋原甲藻(Prorocentrum micans)和中肋骨条藻(Skeletonema costatum)培养中华哲水蚤(Calanus sinicus),研究了各脂肪酸标记对中华哲水蚤摄食不同饵料的指示作用。结果显示,海洋原甲藻中18∶4ω3、22∶6ω3含量较高,中肋骨条藻中16∶1ω7、20∶5ω3的含量较高。二者分别表现出典型的甲藻门和硅藻门的脂肪酸组成特征。中华哲水蚤的脂肪酸组成有两个特点:(1)20∶5ω3和22∶6ω3的含量均较高;(2)其体内表征桡足类浮游植物食性、由桡足类自身合成的20∶1和22∶1脂肪酸占有相当的比例。虽然中华哲水蚤对不同脂肪酸的吸收和转化效率不同,但以脂肪酸作为标记还是成功的指示了中华哲水蚤对微藻的摄食。在饥饿培养中,首先消耗的是那些浮游动物自身不能合成的多不饱和脂肪酸,而结构脂肪酸都表现出了较高的保守性。结合各脂肪酸标记变化趋势和Pearson相关性分析的结果认为,18∶4ω3、18∶4ω3/16∶1ω7、∑18/∑16能较好的指示中华哲水蚤对海洋原甲藻的摄食,仅16∶1ω7/18∶4ω3能指示中华哲水蚤对中肋骨条藻的摄食。The concept of fatty acid trophic marker is based on the fact that the fatty acids of primary producers may be transferred conservatively to,and can be identified in,primary consumers.Recently,fatty acid markers have been widely used to trace or confirm predator-prey relationships so as to illustrate the key trophic linkages in the marine ecosystem.To verify the validity of fatty acid as markers in the trophic relationships between marine algae and the copepod Calanus sinicus,feeding experiment was carried out with this dominant herbivorous copepod from Jiaozhou Bay.During the experiment,Prorocentrum micans and Skeletonema costatum were offered as diets,and starvation was preceded as control.The fatty acid compositions of both the algae and the copepods before and after the experiment were analyzed.Over all,P.micans and S.costatum exhibited different fatty acid patterns.P.micans was characteristic of 18 ∶ 4ω3 and 22 ∶ 6ω3,indicating a typical feature of dinoflagellate.S.costatum was characterized by high amounts of 16 ∶ 1ω7 and 20 ∶ 5ω3,suggesting a systematic status in Bacillariophyceae.Additional,P.micans was found to be much more abundant in the content of total fatty acid than S.costatum.The fatty acid composition of C.sinicus was significantly different from the two algae.Firstly,C.sinicus was rich in both 20 ∶ 5ω3 and 22 ∶ 6ω3,while only one of them was found in large amount in P.micans and S.costatum.Secondly,20 ∶ 1 and 22 ∶ 1 were identified in C.sinicus,demonstrating an herbivorous feeding of this copepod.Although the incorporation and turnover rates of dietary fatty acids were different from each other,the feeding experiment could still provide clear evidence for the potential of specific fatty acids as trophic markers.Polyunsaturated fatty acids which cannot be synthesized by copepods decreased obviously during the starvation experiment,while structural fatty acids with more conservative chemical properties were consumed in a lesser degree.It could be inferred that in the process

关 键 词：中华哲水蚤 海洋原甲藻 中肋骨条藻 脂肪酸 标记 

分 类 号：Q958.8[生物学—动物学]