Foraging modes of stream benthic fishes in relation to their predation effects on local prey density
Foraging modes of stream benthic fishes in relation to their predation effects on local prey density
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溪流底栖鱼类的觅食方式及其捕食对当地猎物密度的影响
DOI：
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发表时间：
2005
影响因子：
2
通讯作者：
Shinzaburo Sone
中科院分区：
文献类型：
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作者：
Mikio Inoue;Masanobu Miyayoshi;Shinzaburo Sone
两种底栖食虫虾虎鱼（Rhinogobius sp.）的栖息地利用和觅食行为。 CO（钴型）和 Rhinogobius sp。在日本四国西南部的一条沿海小溪中，研究了 DA（暗型）对当地猎物密度的捕食影响。觅食范围、觅食尝试频率和水流速度之间的相关性表明，使用快速水流栖息地的个体的觅食范围较小且很少进行觅食尝试，而那些在缓慢水流栖息地的个体则经常在大范围内觅食。前者和后者分别被认为是伏击者和流浪觅食者。栖息地利用、觅食行为和猎物偏好的种间比较表明，Rhinogobius sp。 CO 通过在快速水流中伏击选择性地寻找移动猎物，而 Rhinogobius sp。 DA 通过在慢流栖息地游荡来随机寻找可用的猎物。进行笼子实验来评估猎物迁移率以及捕食对当地猎物密度与当前速度的影响程度。实验结果至少部分支持我们的初步预测：（1）猎物迁移率随着当前速度的增加而增加；（2）鱼类捕食对当地猎物密度的影响随着当前速度的增加而减少。总体结果表明，溪流虾虎鱼的觅食方式与其捕食对当地猎物密度的影响之间存在联系：在快速水流中，鱼类采用伏击式觅食，猎物密度下降幅度较小；而在缓慢水流中，鱼类则主动大面积觅食，猎物减少相对较多。
Habitat use and foraging behavior of two benthic insectivorous gobies, Rhinogobius sp. CO (cobalt type) and Rhinogobius sp. DA (dark type), were examined in relation to their predation effects on local prey density in a small coastal stream in southwestern Shikoku, Japan. Correlations among the foraging range, frequency of foraging attempts and current velocity indicated that individuals using fast-current habitats had small foraging ranges and infrequently made foraging attempts while those in slow currents frequently foraged over large areas. The former and the latter were recognized as ambush and wandering foragers, respectively. Interspecific comparisons of habitat use, foraging behavior and prey preference suggested that Rhinogobius sp. CO selectively forage mobile prey by ambushing in fast currents, whereas Rhinogobius sp. DA randomly forage available prey by wandering in slow-current habitats. A cage experiment was conducted to assess prey immigration rate and the degree of predation effects on local prey density in relation to current velocity. The results of the experiment support, at least in part, our initial predictions: (1) prey immigration rates increase with current velocity and (2) the effects of fish predation on local prey density are reduced as current velocity increases. Overall results illustrated a link between the foraging modes of the stream gobies and their predation effects on local prey density: fish adopt ambush foraging in fast currents, where the decrease in prey density tends to be less, whereas fish actively forage over large areas in slow currents, where the decrease in prey is relatively large.