Effects of Irrigation On Growth of Polychaetes in Sedimentary Environments

9314681 Marinelli一类潜在的重要底栖生物之间的相互作用涉及底栖动物驱动的沉积环境化学变化和其他生物对这种变化的反应。该项目将研究一项重要的动物群活动，即多毛虫灌溉洞穴，如何影响共生生物体的生长。多毛类是沉积组合中的优势类群。根据物种特有的特性和群落组织，对穴灌的重要性进行了评估。要解决的具体问题包括：(1)共生生物的洞穴灌溉在多大程度上影响单个多毛类的生长？效益是否与灌溉洞穴的密度和分布以及灌溉的频率有关？(2)个体在多大程度上感受到穴位灌溉的益处取决于个体的生理或管道特征？(3)底栖群落中多毛类之间的生物-化学相互作用如何受到其他生物过程的影响，如竞争或捕食？这些问题将使用一种综合的方法进行评估，该方法结合了生物体的生物学以及沉积物中的运输和反应过程。这种方法包括在实验室和野外进行操纵性实验，以及对影响和/或受动物群影响的目标物质进行成岩模拟。规划期内的研究将探讨使用多毛类生长或生长潜力的生化指标的可行性。这些指标包括(1)脂质成分分析和(2)RNA/DNA比率。这些指数已被证明是检查一些海洋无脊椎动物和脊椎动物分类的营养状况和环境条件的有用工具，包括桡足类、鱼类、棘皮动物、双壳类和甲壳类。这些多毛类技术的发展将为研究底栖生物组合中突出分类群的生态和环境问题提供一种重要的替代方法。规划研究是一个必要的先导，因为通常使用的评估多毛类生长的方法可能是不够的。综上所述，规划期的研究以及未来将开展的研究项目，将为推动底栖生物分布和相互作用的力量提供一个新的视角。此外，它们将对了解不同的大型动物组合如何影响沉积物中的溶质运输，以及评估多毛类在自然环境中的营养状况或生长潜力具有重要意义。***

9314681 MARINELLI A potentially important class of interactions among infaunal organisms involves infaunal-driven changes in the chemistry of the sedimentary environment and responses of other organisms to the modification. This project will examine how one important infaunal activity, irrigation of burrows by polychaete worms, affects the growth of co-occurring organisms. Polychaetes are a dominant taxon in sedimentary assemblages. Evaluation of the importance of burrow irrigation is made in light of species-specific traits and community organization. The specific questions to be addressed include: (1) To what extent does burrow irrigation by co-occurring organisms affect the growth of individual polychaetes? Is the benefit related to the density and distribution of irrigated burrows, and the frequency of irrigation?; (2) To what extent is the benefit of burrow irrigation experienced by an individual dependent on the physiology or tube characteristics of the individual?; (3) How are biological-chemical interactions among the polychaetes affected by other biological processes, such as competition or predation, in benthic communities? These questions will be evaluated using a combined approach that incorporates the biology of organisms, and transport and reaction processes in sediments. This approach includes manipulative experimentation in the laboratory and field, and diagenetic modelling of target substances that affect, and/or are influenced by, infauna. The research in the planning period will examine the feasibility of using biochemical indices of growth or growth potential for the polychaetes. These indices include (1) analysis of lipid composition and (2) RNA:DNA ratios. These indices have proven useful as tools for examining nutritional status and environmental conditions for a number of marine invertebrate and vertebrate taxa, including copepods, fish, echinoderms, bivalves, and crustaceans. Development of these techniques for the polychaetes wo uld provide an important alternative method for examining ecological and environmental questions for a prominent taxon in benthic assemblages. The planning research is a necessary precursor because commonly-used methods of assessing growth in polychaetes are likely to be inadequate. Taken together, the research in the planning period, and the future to be developed research project, will provide a novel perspective on the forces which drive the distributions of, and interactions between benthic organisms. Furthermore, they will have important implications for understanding how different macrofaunal assemblages affect solute transport in sediments, and evaluating the nutritional status or growth potential of polychaetes in the natural environment. ***