Hill Cathy, Elmgren Ragnar
Department of Zoology, Stockholm University, S-106 91, Stockholm, Sweden.
Department of Systems Ecology, Stockholm University, S-106 91, Stockholm, Sweden.
Oecologia. 1992 Aug;91(2):153-156. doi: 10.1007/BF00317777.
Predation by Saduria entomon on the depositfeeding amphipods Monoporeia (=Pontoporeia) affinis and Pontoporeia femorata was studied in laboratory experiments. Prey vulnerabilities were compared in singleprey treatments and in mixed-prey treatments, where the proportions of the two species were varied at one total density. In a pilot experiment, P. femorata was the more vulnerable prey, both in single-prey and mixed-prey treatments. In later experiments, the amphipod species were equally vulnerable in single-prey treatments, while in mixed-prey treatments Saduria preyed preferentially on M. affinis, even when this prey was rare, i.e. it did not "switch". We suggest that the different result in the later experiments may have been due to a change in the search mode of the isopods.
在实验室实验中研究了萨杜里亚虫（Saduria entomon）对沉积取食性双壳纲动物细纹单孔贝（Monoporeia (=Pontoporeia) affinis）和股孔单孔贝（Pontoporeia femorata）的捕食情况。在单猎物处理和混合猎物处理中比较了猎物的脆弱性，在混合猎物处理中，两种物种的比例在一个总密度下变化。在一个预实验中，无论是在单猎物处理还是混合猎物处理中，股孔单孔贝都是更易受攻击的猎物。在后来的实验中，在单猎物处理中这两种双壳纲动物同样易受攻击，而在混合猎物处理中，萨杜里亚虫优先捕食细纹单孔贝，即使这种猎物很稀少，即它不会“转换”。我们认为后来实验中不同的结果可能是由于等足类动物搜索模式的改变。
