Studies on the Physiological Ecology of Hydrothermal Vent Chemoautotrophic Symbioses

9632861奇尔德里斯喷口动物群是全球分布于深海的古老动物群。在分类学上，它与其他深海生物群落的亲缘关系有限，但与深海碳氢化合物渗漏和其他渗漏环境的动物群有亲缘关系。这种深海喷口环境可能是保护喷口生物群免受对其他群落产生重大影响的灭绝事件影响的避难所。因此，深海热液喷口是地球上主要的生态系统类型之一，但可能是最鲜为人知的。这些群落的存在取决于一些无脊椎动物/细菌共生体利用周围深海水中的氧化剂（氧气或硝酸盐）氧化喷口中还原的化学物质（硫化物或甲烷）的能力，以推动初级生产。因此，共生体与喷口环境的化学特性相互作用的能力对于支持这些生态系统的初级生产至关重要。该项目的中心目标是描述和量化管虫Riftia pachyptila与流过它的喷口流体的化学相互作用，以便可以为整个动物组合模拟这些相互作用。该项目包括根据对新收集的蠕虫进行的测量，制定生长率、初级生产、状况和环境条件的指数。该项目有3个组成部分：1）调查不同的喷口和渗漏环境，以确定化能自养共生体对各种不同条件的反应。其目的是量化从新鲜捕获的蠕虫样本的参数范围广泛，并将这些与环境特征，以便在现场的蠕虫与喷口流体的相互作用可以估计。2)支持共生喷口动物自养的生理学的船上研究。这些研究的目的是测量Riftia与各种化学参数的相互作用，以及温度对这些相互作用的影响，以了解蠕虫的功能。长期维持蠕虫在压力水族馆的生长研究是这些计划研究的一部分。3)在13 N.这包括部署温度记录器，以测量条件的变化，并对生物群进行选定的观察，以描述随时间的变化。其目的是在较长的时间尺度上描述管虫的生态位，以便能够在较长的时间内估计初级生产和与喷口流体的相互作用。该项目将大大增加我们对喷口动物及其化学环境之间相互作用性质的了解，有助于我们了解喷口和其他化能自养支持的生态系统的功能。

9632861 CHILDRESS The vent fauna is an ancient fauna of global distribution in the deep-sea. It has limited taxonomic affinities to other deep sea communities, and yet it has affinities to the faunas of deep-sea hydrocarbon seeps and other seep environments. This deep-sea vent environment may have been a refuge protecting vent taxa from the extinction events which had great impacts on other communities. Thus, deep-sea hydrothermal vents are one of the major ecosystem types on the earth, but probably the least known. The existence of these communities depends upon the ability of a few invertebrate/ bacteria symbioses to oxidize reduced chemical species (sulfide or methane) from the vents using oxidants (oxygen or nitrate) from the surrounding deep-sea water to power primary production. Thus the capacities for interaction of the symbioses with the chemical properties of vent environments is fundamental to the primary production which supports these ecosystems. The central objective of this project is to describe and quantify the chemical interactions of the tubeworm Riftia pachyptila with the vent fluids which flow over it so that these interactions can be modeled for entire assemblages of animals. This project includes development of indices of growth rate, primary production, condition, and environmental conditions based on measurements made on freshly collected worms. The project has 3 components: 1) Survey of diverse vent and seep environments to determine the responses of chemoautotrophic symbioses to widely differing conditions. The objective is to quantify a broad range of parameters on samples from freshly captured worms and to correlate these with environmental characteristics so that the in situ interactions of the worms with the vent fluids can be estimated. 2) Shipboard studies of the physiology supporting autotrophy in symbiotic vent animals. The objective of these studies is to measure the interactions of Riftia with the various chemical parameters, a s well as the effects of temperature on these interactions, to develop an understanding of the functioning of the worms. Long term maintenance of worms in pressure aquaria for growth studies is part of these projected studies. 3) The observation and measurement of temporal changes at 13 N. This includes deployment of temperature recorders to measure the variation in conditions and selected observations of the biota to describe the changes over time. The objective is to describe the niche of the tubeworm on longer time scales so that primary production and interactions with vent fluids can be estimated over longer time periods. This project will greatly increase our understanding of the nature of the interactions between the vent animals and their chemical environments, contributing to our understanding of the functioning of the vent and other chemoautotrophically supported ecosystems.