On the Significance of Doliolids as Consumers and Producers

9633401 Paffenhofer该项目将调查doliolids（被囊纲，海樽纲）控制原生动物和自由产卵的哲水蚤桡足类丰度的能力。远洋被囊动物的摄食率一直难以量化，特别是海樽纲。在这项工作中，Paffenhofer和Verity博士将同时量化doliolids的摄食，生长和繁殖率，这些doliolids反复构成温带和亚热带沃茨浅海浮游动物的主要组成部分。其主要假设是：（1）600个以上的大型动物m-3以上的硅砾藻组合能够控制浮游植物、浮游原生动物和自由产卵的哲水蚤;（2）如此高浓度的大型硅砾藻是通过两个连续无性阶段的强烈繁殖和高个体生长率迅速获得的。这些研究的意义有几个方面：第一，获得环境现实和同步信息的消费和生产率的不同doliolid类动物;第二，实验确定在何种浓度doliolids控制浮游植物，浮游原生动物和自由产卵的哲水蚤;第三，开发一个模型描述的直接和间接影响的doliolid组合可以对这些猎物种群。***

9633401 Paffenhofer This project will investigate the ability of doliolids (Tunicata, Thaliacea) to control the abundance of protozoa and free-spawning calanoid copepods. Pelagic tunicate feeding rates have been difficult to quantify, particularly for Thaliacea. In this work, Drs. Paffenhofer and Verity will quantify simultaneously the feeding, growth and reproduction rates of doliolids, which repeatedly have constituted a major component of neritic zooplankton in temperate and subtropical waters. The main hypotheses are that:(1) doliolid assemblages above ~ 600 large zooids m -3 are able to control phytoplankton, protozooplankton and free- spawning calanoids, and (2) that such high concentrations of large doliolids are rapidly attained by intense reproduction of two consecutive asexual stages, and high individual grown rates. The significance of these studies is several fold: first, to obtain environmentally-realistic and simultaneous information on rates of consumption and production of the different doliolid zooids; second, determine experimentally at which concentrations doliolids control phytoplankton, protozooplankton and free-spawning calanoids; third, develop a model describing the direct and indirect effects which a doliolid assemblage can have on these prey populations. ***