Effects of Irrigation On Growth of Polychaetes in Sedimentary Environments

水生生物之间潜在的一类重要相互作用涉及由水生生物驱动的沉积环境化学变化以及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活动，即多毛类蠕虫对洞穴的灌溉，如何影响共生生物的生长。多毛类是沉积组合中的优势分类群。从物种特征和群落结构两方面评价了洞灌的重要性。需要解决的具体问题包括：(1)共存生物的穴居灌溉在多大程度上影响了单个多毛体的生长？这种效益是否与灌溉地穴的密度、分布和灌溉频率有关？(2)在多大程度上，穴居灌溉对个体的益处取决于个体的生理或管状特征？(3)在底栖生物群落中，其他生物过程（如竞争或捕食）如何影响多毛体之间的生物化学相互作用？这些问题将使用结合生物生物学和沉积物中的运输和反应过程的综合方法进行评估。这种方法包括在实验室和现场进行操作实验，以及对影响动物和/或受动物影响的目标物质进行成岩模拟。计划期内的研究将探讨利用生长生化指标或生长潜力来研究多毛类的可行性。这些指标包括(1)脂质组成分析和(2)RNA:DNA比率。这些指数已被证明是检验许多海洋无脊椎动物和脊椎动物类群（包括桡足类、鱼类、棘皮类、双壳类和甲壳类）营养状况和环境条件的有用工具。这些技术的发展将为研究底栖生物群落中一个突出的分类群的生态和环境问题提供一个重要的替代方法。规划研究是一个必要的先导，因为评估多毛类生长的常用方法可能是不充分的。总的来说，规划期的研究和未来有待开发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，它们将对了解不同大型动物组合如何影响沉积物中的溶质运输，以及评估自然环境中多毛类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. ***