The diet of deep-sea macrobenthic isopods (Crustacea, Malacostrace) and polychaetes (Annelida) with focus on the importance of foraminiferans for their nutrition

对深海生态系统功能的有限调查仍留下许多未解之谜。南大洋深海的情况也是如此，那里原生动物有孔虫、有孔虫甲壳类动物（即等足类动物）和多毛类蠕虫的数量很多。为了了解它们的生态相互作用，拟议项目的目的是：（1）调查深海等足类动物和多毛类动物的饮食，重点是有孔虫的作用;（2）建立分子方法，以确定无脊椎动物肠道内容物;（3）揭示与不同的摄食偏好有关的可能机制，这种偏好可能是深海分类群高度多样性的基础。将分析前四次极地船考察（ANDEEP I-III和PINCOCO）的海底表层样品以及新材料。为了回答有针对性的问题，将采用选定的方法，包括显微镜肠道内容物分析，研究口器的功能形态以及设计和优化遗传引物，以基于PCR方法进行肠道内容物分析（即使在肠道内容物无法通过显微镜识别的情况下也适用）。后者包括测试不同的通用引物，以开发用于分析生物体一般饮食的合适方法，以及应用有孔虫特异性引物，以确定不同有孔虫物种在等足类和多毛类饮食中的作用。研究结果不仅将提供关于南大洋深海大型底栖生物饮食的信息，包括有孔虫的作用，而且还将为今后分析各种生物的饮食提供一个创新工具。

The limited investigations studying the functioning of abyssal ecosystems still leave many unanswered questions. This is also the case for the Southern Ocean deep sea, a habitat with high abundances of protozoan foraminiferans, peracarid crustaceans (namely isopods) and polychaete worms. To gain knowledge on their ecological interactions, the proposed project aims at 1) investigating the diet of abyssal isopods and polychaetes, focusing on the role of foraminiferans, 2) the establishment of molecular methods to identify invertebrate gut contents, and 3) revealing possible mechanisms connected with distinct feeding preferences which might underlie the high degree of diversity found in deep-sea taxa. Epibenthic sledge samples from four previous Polarstern expeditions (ANDEEP I-III and SYSTCO) as well as new material will be analysed. To answer the targeted questions, selected methods will be employed including microscopic gut content analysis, studying functional morphology of mouthparts as well as the designing and optimisation of genetic primers to conduct gut content analyses based on PCR methods (which are even applicable if the gut content is not identifiable by microscopy). The latter include the testing of different universal primers to develop a suitable method for the analyses of an organism’s general diet as well as the application of foraminiferan specific primers to define the role of different foraminiferan species in the diet of isopods and polychaetes. The results will not only deliver information on the diet of deep sea macrobenthos of the Southern Ocean including the role of foraminiferans, but also provide an innovative tool to analyse the diet of various organisms in the future.