Subtle top‐down control of a freshwater meiofaunal assemblage by juvenile fish
Subtle top‐down control of a freshwater meiofaunal assemblage by juvenile fish
复制标题
幼鱼对淡水小型动物群的微妙自上而下控制
DOI：
10.1111/j.1365-2427.2010.02416.x
复制
发表时间：
2010
影响因子：
2.7
通讯作者：
A. Robertson
中科院分区：
文献类型：
--
作者：
G. Dineen;A. Robertson
总结
1.自上而下的控制猎物组合的鱼类捕食者已经清楚地表明，在湖泊（浮游动物的猎物）和河流（大型无脊椎动物的猎物）。鱼类捕食可以有一个显着的影响，对猎物组合的身体大小，往往是大型的猎物减少的丰度，和间接促进小型的猎物发生潜在的启动营养级联。
2.水生生态系统中的底栖生物群落也包括许多具有重要功能的小型底栖生物组成部分，但在淡水中，鱼类捕食对小型底栖生物组合的影响尚不清楚。我们使用了一个实验室的微观宇宙研究，探讨幼鱼捕食的影响，丰富和大小结构的河流小型底栖动物组合。
3.在我们的微观世界中，鱼类的存在对整体小型底栖动物（临时和永久）丰度没有显着影响。然而，桡足类，我们发现了第一个证据的自上而下的控制淡水小型底栖动物组合，在与幼鱼的缩影中，大型桡足类的丰度显着减少，而小型桡足类显着更丰富的间接促进。
4.我们的结论是，幼鱼捕食可以改变淡水小型底栖动物组合的结构，虽然我们还不知道这些相对微妙的变化是否被大规模的事件，如流量扰动所淹没。
Summary
1. Top-down control of prey assemblages by fish predators has been clearly demonstrated in lakes (for zooplankton prey) and rivers (for macroinvertebrate prey). Fish predation can have a significant impact on the body size of prey assemblages; often large-bodied prey are reduced in abundance, and indirect facilitation of small-bodied prey occurs potentially initiating a trophic cascade.
2. Benthic communities in aquatic ecosystems also include a numerous and functionally important meiofaunal-sized component, but in freshwaters the impact of fish predation on meiofaunal assemblages is unknown. We used a laboratory microcosm study to explore the impact of juvenile fish predation on the abundance and size structure of a riverine meiofaunal assemblage.
3. The presence of fish in our microcosms had no significant effect on overall meiofaunal (temporary and permanent) abundance. However, for the Copepoda, we found the first evidence of top-down control of freshwater meiofaunal assemblages; in microcosms with juvenile fish, the abundance of large-bodied Copepoda was significantly reduced, whereas small-bodied Copepoda were significantly more abundant suggesting indirect facilitation.
4. We conclude that predation by juvenile fish can alter the structure of freshwater meiofaunal assemblages, although we do not yet know whether these relatively subtle changes are overwhelmed by large-scale events such as flow disturbances.