Bacterivorous Ciliates in Marine Food Webs: Lipid Chemistry and Copepod Nutrition

食菌纤毛虫是浮游食物网的重要组成部分。它们可以消耗很大比例的细菌生产，并将基本脂肪含量较低的物质(细菌生物量和碎屑)转化为富含脂肪的纤毛虫生物量。消费者如何从这些纤毛虫中获得营养上的好处，它们在纤毛虫碳的生化转化中扮演了什么角色？为了研究纤毛虫脂肪的性质及其在海洋食物网中的命运和重要性，哈维博士和麦克马努斯博士将：-识别和量化纤毛虫脂肪，特别是那些在营养研究中可能作为群体特异性生物标志物有用的纤毛虫脂肪。-检查纤毛虫饮食中的脂类来源，并跟踪纤毛虫如何吸收和修改膳食脂类。-测量纤毛虫主要消费者之一--桡足类对纤毛虫脂肪的同化和转化。该项目将生化测量与饲养实验相结合。对一些纤毛虫物种的详细脂肪分析将首先提供关于他们已经观察到的独特化合物普遍存在的额外数据。他们将详细测量食物对几种典型的食菌性纤毛虫的脂肪含量和分布的影响。最后，他们将进行深入的摄食实验，以跟踪食草性桡足类对纤毛虫脂肪的并入和转化。这些结果将为食菌性纤毛虫在海洋食物网中的作用提供大量新的信息，特别是它们在桡足类营养中的重要性。

Bacterivorous ciliates are an important component of planktonic food webs. They can consume a large proportion of bacterial production, and convert material that is low in essential lipids (bacterial biomass and detritus) into lipid-rich ciliate biomass. How do consumers benefit nutritionally from these ciliates, and what role do they play in the biochemical transformation of ciliate carbon? To investigate the nature of ciliate lipids and their fate and importance in the marine food web Dr. Harvey and McManus will: - identify and quantify ciliate lipids, especially ones that may be useful as group-specific biomarkers in trophic studies. - examine sources of lipids in the ciliate diet and follow how ciliates assimilate and modify dietary lipids. - measure the assimilation and transformation of ciliate lipids by one of their principal consumers, copepods. This project combines biochemical measurements with feeding experiments. Detailed lipid analysis of a number of ciliate species will first provide additional data on the ubiquity of the unique compounds they have already observed. They will measure in detail the role of diet on lipid content and distribution of several representative bacterivorous ciliates. Finally, they will conduct in-depth feeding experiments to follow the incorporation and transformation of ciliate lipids by grazing copepods. These results will provide substantial new information on the role of bacterivorous ciliates in the marine food web, especially their importance in copepod nutrition.