Linkage between microbial loop and grazing food chain in benthic environments of streams

1.我们确定了垂直变化的流速和溶解氧饱和度的生物膜上的人工和天然基板上使用微电极。流速与深度的垂直剖面表明存在粘性底层。研究结果还表明，基质表面的光滑度与溶解氧饱和度的垂直分布有关.在河床卵石生物膜的微生物生产力的各种测量分析了几乎每月一年，以量化的重要性，初级生产作为一个土生土长的有机物质来源，用于支持异养细菌生产的动态食物网在这个自然的微生物栖息地。这可能是本地和外来的有机物质供应是重要的生产细菌的卵石生物膜中发展迅速流动的淡水流。2004年7月至8月，我们在爱媛县的日治海峡（其主要水源是一个富营养化水库）研究了水生昆虫对微藻的食物选择性。研究结果表明，当微囊藻的殖民地较小时，红腹锦鸡儿对微囊藻有选择性摄食，对盘星藻和针座藻等真核微藻也有选择性摄食.为了验证附着生物和食草动物之间的线索通信的假设，我们进行了两种实验室通道实验，使用案件轴承石蛾食草动物（Glossosoma spp.）和微藻提示。尽管对粒子线索的选择性（即，化学气味和视觉漂流微藻）的选择性高于溶解的线索（仅化学气味），颗粒和溶解的线索之间的选择性也没有显著差异。因此，可以得出结论，舌体鱼幼虫能够检测视觉（即，漂流的微藻）和化学线索。

1. We determined vertical changes in flow velocity and dissolved oxygen saturation in biofilms on artificial and natural substrates using microelectrodes. Vertical profile of current velocity versus depth indicated a presence of viscous sublayer. Our results also suggest smoothness of substrate surface is related to vertical profile of DO saturation.2. Various measurements of microbial productivity in streambed pebble biofilms were analyzed almost monthly for one year to quantify the importance of primary production as an autochthonous source of organic matter utilized to support heterotrophic bacterial production in the dynamic food web within this natural microbial habitat. It is likely that both autochthonous and allochthonous supplies of organic matter are important for production of bacteria in the pebble biofilms that develop in rapidly flowing fresh water streams.3. We examined food selectivity on microalgae by aquatic insects in Hiji Steram, Ehime, whose main water source is a eutrophic reservoir, from July to August 2004. Our results suggest that Cheumatopsyche selectively grazes on Microcystis when the size of the colony is small, and that the insect shows selective grazing on some eukaryotic microalgae such as Pediastrum and Synedra.4. To test hypotheses relating the cue communication between periphyton and grazers, we performed two kinds of laboratory channel experiments using case-bearing caddisfly grazer (Glossosoma spp.) and microalgal cue. Although the selectivity to the particle cue (i.e., chemical scent and visual drifting microalgae) was higher than that of the dissolved cue (only chemical scent), the selectivity was also not significantly different between the particle and the dissolved cues. Thus, it was concluded that Glossosoma larvae were able to detect both the visual (i.e., drifted microalgae) and the chemical cues.