Introduction of the non-indigenous amphipod Gammarus pulex alters population dynamics and diet of juvenile trout Salmo trutta
Introduction of the non-indigenous amphipod Gammarus pulex alters population dynamics and diet of juvenile trout Salmo trutta
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DOI：
10.1111/j.1365-2427.2004.01315.x
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发表时间：
2005-01-01
影响因子：
2.7
通讯作者：
Dick, JTA
中科院分区：
文献类型：
--
作者：
Kelly, DW;Dick, JTA
1.片足类Gammarus pulex，引入爱尔兰河流的目的是提高鳟鱼喂养，正在取代本地Gammarus duebeni celticus。这两个物种通常与不同的环境条件和大型无脊椎动物群落，混淆评估的影响，入侵者与本地鱼类种群。在这里，我们从环境梯度中分离出两种钩虾的影响。一个堰将利桑河的一段低地分开，减缓了G. pulex和相邻的G.蚤状蚤、混合种和蚤状蚤。D.凯尔特人到达。底栖无脊椎动物的总丰度和生物量均显著高于长江三角洲。pulex reach，由高入侵丰度驱动，其他类群丰度低。蚤状钩虾的夜间漂移尤为突出.相应地，0+鳟鱼的密度和生物量在G。pulex reach，而瞬时损失率较低。三个河段的鱼类生长率相似.在G.在pulex河段，这种入侵者控制了0+鳟鱼的饮食，导致摄入的无脊椎动物生物量明显高于其他河段的鱼类。鱼类对钩虾的捕食一般与其丰度成比例，但对钩虾表现出一定的正选择作用。入侵范围内的蚤状虫.本地的无脊椎动物的入侵者的负面影响进行了对比与青少年鳟鱼的积极影响。这表明入侵后能量通量的变化，与不同的资源利用或同化G。可能的潜在机制。随着片足类动物入侵的频率在全球范围内的增加，如果要预测故意和无意引入的后果，并最终预防，则需要调查它们在生态组织的多个层面上作为强相互作用者的作用。
1. The amphipod Gammarus pulex, introduced to Irish rivers with the aim of enhancing trout feeding, is displacing the native Gammarus duebeni celticus. These two species are generally associated with different environmental conditions and macroinvertebrate communities, confounding assessment of effects of the invader as compared with the native on fish populations. Here, we uncouple effects of the two Gammarus species from environmental gradients.2. A weir dissects a lowland stretch of the River Lissan, slowing the upstream invasion by G. pulex and resulting in contiguous G. pulex, mixed species and G. d. celticus reaches. Total invertebrate abundance and biomass in the benthos were significantly higher in the G. pulex reach, driven by high invader abundance, with low abundance of other taxa. Gammarus pulex was particularly prominent in night-time drift.3. Correspondingly, densities and biomass of 0+ trout were significantly higher in the G. pulex reach, while instantaneous loss rates were lower. Fish growth rates were similar among the three reaches.4. In the G. pulex reach, this invader dominated the diet of 0+ trout, leading to ingestion of significantly higher invertebrate biomass than fish in the other reaches. Fish generally preyed on Gammarus in proportion to its abundance, but exhibited some positive selection for G. pulex in the invaded reach.5. The negative effects of the invader on native invertebrates are contrasted with positive effects on juvenile trout. This indicates changes in energy flux after invasion, with differential resource use or assimilation by G. pulex probable underlying mechanisms. As the frequency of amphipod invasions increases globally, investigations of their role as strong interactors at multiple levels of ecological organisation is required if the consequences of deliberate and unintentional introductions are to be predicted, and ultimately, prevented.