Avoidance by Daphnia magna of fish and macrophytes: Chemical cues and predator‐mediated use of macrophyte habitat
Avoidance by Daphnia magna of fish and macrophytes: Chemical cues and predator‐mediated use of macrophyte habitat
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DOI：
10.4319/lo.1996.41.4.0794
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发表时间：
1996-06
影响因子：
4.5
通讯作者：
T. Lauridsen;D. Lodge
中科院分区：
文献类型：
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作者：
T. Lauridsen;D. Lodge
最近的生物操纵研究表明，大型水生植物是大型浮游动物免受鱼类捕食的重要避难所。我们进行了两个实验室实验，测试大型蚤的行为反应的大型水生植物（狐尾藻exalbescens L。）和太阳鱼（Lepomis cyanellus Rafinesque），以及反应是否是化学（鱼类）或结构（大型植物）介导的。在第一个实验中，我们测量了水蚤在不同的38升水箱中对四种处理的反应。在没有水生植物和鱼类的对照组中，15%的水蚤被发现在中心区域（约50%的水箱面积）;其他的被发现在水箱周边（特别是在角落）。与大型植物的存在，80%的水蚤被发现在中心区（在所有治疗无植被）。当鱼或鱼的气味单独存在时，分别有35%和45%的水蚤占据中心区域。因此，化学介导的Lepomis回避引起水蚤增加其占领的水生植物。在第二个实验中，我们测试了狐尾藻的驱避效果是否是由于大型植物的结构特征造成的;结果表明，化学和结构线索都有助于水蚤回避大型植物。总体而言，我们的研究结果是一致的建议，大型浮游动物可能会使用水生植物作为避难所在浅水湖泊的垂直迁移受到限制。
Recent biomanipulation studies suggest that macrophytes are an important refuge from fish predation for large pelagic zooplankton. We conducted two laboratory experiments that tested the behavioral responses of Daphnia magna to a macrophyte (Myriophyllum exalbescens L.) and a sunfish (Lepomis cyanellus Rafinesque) and whether responses were chemically (for fish) or structurally (for macrophytes) mediated. In the first experiment, we measured Daphnia response to four treatments in separate 38-liter tanks. In controls without macrophytes and fish, ∼ 15% ofthe daphnids were found in the central zone (∼ 50% of the tank area); the others were found around the tank perimeter (especially in the corners). With macrophytes present, 80% of the daphnids were found in the central zone (unvegetated in all treatments). When fish or fish odor alone were present 35% and ∼45%, respectively, of the Daphnia occupied the central zone. Thus, chemically mediated avoidance of Lepomis caused Daphnia to increase its occupation of macrophytes. In the second experiment, we tested whether the repellent effect of Myriophyllum resulted from structural characteristics of the macrophyte; the results suggest that both chemical and structural cues contributed to Daphnia avoidance of the macrophyte. Overall, our results are consistent with the suggestion that large pelagic zooplankton may use macrophytes as a refuge in shallow lakes where vertical migration is restricted.