The Importance of Inter-species Predation among Marine Ciliate Protozooplankton

纤毛虫对其他纤毛虫的捕食在浮游原生动物中很常见，可能是次生生产力转移的重要途径。切萨皮克湾物种间纤毛虫捕食的影响将通过实验室实验、野外种群操纵以及对纤毛虫原生浮游动物丰度、物种组成和饮食习性的调查相结合的方式进行研究。提出：1)纤毛虫间捕食者是海洋原生浮游动物群落中一致的和局部丰富的组成部分；2)细菌和草食性纤毛虫的大量次生生产力被纤毛虫捕食消耗；3)种间纤毛虫捕食者的捕食和生长速度足以利用和潜在地控制当地密集的猎物种群。海洋原生浮游动物中纤毛虫的大量和广泛存在表明，它们在海洋浮游食物网中发挥着关键作用。纤毛虫作为浮游植物和浮游细菌的消费者的重要性已经得到了很好的研究，现在已经被普遍接受。虽然大型浮游动物一直被视为纤毛虫的主要消费者，但几乎没有证据表明后生动物的放牧对纤毛虫种群有实质性影响。因此，纤毛虫二次生产的命运仍然存在不确定性。科茨设计了一系列猎物交换实验，以检验某些种类的纤毛虫本身消耗了大量这种次级产品的假设。最近发现，海洋中的许多动植物相互作用是由这些微生物的活动所主导的，这项新的工作将阐明纤毛虫间捕食在海洋食物网中的作用。

Ciliate predation on other ciliates is common among members of the protozooplankton and may be a significant pathway through which secondary production is transferred. The impact of inter- species ciliate predation in Chesapeake Bay will be studied through a combination of laboratory experiments, manipulations of field populations, and surveys of ciliate protozooplankton abundance, species composition, and dietary habits. It is proposed that: 1) inter-ciliate predators are a consistent and locally abundant component of the marine protozooplankton community; 2) a significant amount of secondary production by bacterivorous and herbivorous ciliates is consumed by ciliate predation; 3) grazing and growth rates of inter-species ciliate predators are sufficient to exploit and potentially control locally dense prey populations. The abundance and widespread occurrence of ciliated protozoa among the marine protozooplankton suggest that they play a pivotal role in the planktonic food web of the ocean. The importance of ciliates as consumers of phytoplankton and, to a lesser extent, bacterioplankton has been well studied and is now generally accepted. While large zooplankton have been viewed as the predominant consumers of ciliates, there is little evidence indicating that grazing by metazoa has a substantial impact on ciliate populations. Therefore, uncertainty still exists as to the fate of secondary production by ciliates. Coats has designed a series of prey switching experiments to examine the hypothesis that certain species of the ciliates themselves consume much of this secondary production. It has recently become apparent that much of the plant - animal interactions in the sea are dominated by the activities of such microbial organisms and this novel work will clarify the role of inter - ciliate predation in marine food webs.