Studies of Microbial Foodwebs: I. Nutrition and Growth Rates of Phagotrophic Nanoflagellates in a Coastal Pelagic Foodweb

在远洋系统中，微生物食物网代表了固定碳到后生动物食物链的主要环节，而与此同时，浮游植物生产的很大一部分是由微生物呼吸的。最近的研究表明，小于5微米的吞噬性鞭毛虫是微浮游生物的主要捕食者，而稍大的鞭毛虫（5-10微米）既消耗小于5微米的自养细胞，也消耗异养细胞，大于10微米的鞭毛虫和纤毛虫捕食较小的鞭毛虫。也有初步数据表明，一些吞噬性鞭毛虫可能能够直接吸收高分子量溶解有机物（DOM）。本研究旨在研究盐沼河口开放水域中三种大小的纳米浮游生物（小于5微米、5-10微米和大于10微米）的营养来源，包括DOM、细菌和蓝藻、浮游植物和无色鞭毛虫，以及吞噬性鞭毛虫的生长速度。

In pelagic systems, the microbial foodweb represents the primary link for fixed carbon to metazoan food chains, while at the same time a large fraction of phytoplankton production is respired by microbes. Recent studies suggest that phagotrophic flagellates less than 5 um are the dominant grazers of picoplankton, while slightly larger flagellates (5-10 um) consume both autotrophic and heterotrophic cells less than 5um, and flagellates and ciliates larger than 10 um prey on smaller flagellates. There is also preliminary data that suggest that some phagotrophic flagellates may be capable of direct uptake of high molecular weight dissolved organic matter (DOM). This research is to examine the sources of nutrition, including DOM, bacteria and cyanobacteria, phytoplankton and colorless flagellates, as well as the rates of growth, of phagotrophic flagellates in three size classes of nanoplankton (less than 5 um, 5-10 um, and greater than 10 um) in the open waters of a salt marsh estuary.