Food habit divergence between white-spotted charr and masu salmon in Japanese mountain streams: circumstantial evidence for competition
Food habit divergence between white-spotted charr and masu salmon in Japanese mountain streams: circumstantial evidence for competition
复制标题
日本山间溪流中的白点红点鲑和马苏鲑鱼的食性差异：竞争的间接证据
DOI：
10.1007/s10201-002-0088-4
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发表时间：
2003
期刊：
影响因子：
1.6
通讯作者：
T. Furukawa
中科院分区：
文献类型：
--
作者：
H. Miyasaka;S. Nakano;T. Furukawa
的饮食和觅食的微生境的白斑红点鲑，红点鲑，进行了比较，山溪达到它发生（同域）和没有（异域）马苏鲑鱼，虹鳟，一个潜在的竞争对手，研究这些鱼类之间的种间竞争的证据，这通常共同出现在日本的山溪。在三个流检查，饮食的异域charr和鲑鱼之间的相似性远大于同域charr和鲑鱼之间的饮食。这两个allopatric charr和同域鲑鱼集中利用流漂流（52%-65%的饮食）之间的陆地无脊椎动物，而这类猎物只占同域charr饮食的中间部分（11%-29%）。可用的猎物组成流漂流物的检查表明，消费的陆地无脊椎动物的异域charr和同域鲑鱼约两倍，同域charr。鲑鱼的存在，一个潜在的竞争对手，可能会改变饮食的charr在同域河段。Charr持有焦点更接近河床被认为效率较低，比同域鲑鱼在其利用的陆地无脊椎动物漂流主要在流表面，虽然觅食的小生境的charr鲑鱼没有受到影响。负责同域性红点鲑和鲑鱼之间的饮食分歧的机制可能是陆地无脊椎动物漂流在流表面争夺竞争的结果。
The diet and foraging microhabitat of white-spotted charr,Salvelinus leucomaenis, were compared between mountain stream reaches where it occurs with (sympatric) and without (allopatric) masu salmon,Oncorhynchus masou masou, a potential competitor, to examine the evidence for interspecific competition between these fish, which commonly co-occur in Japanese mountain streams. In three streams examined, the similarity between the diets of allopatric charr and salmon was much greater than that between the diets of sympatric charr and salmon. Both allopatric charr and sympatric salmon intensively utilized terrestrial invertebrates among stream drifts (52%–65% of the diet), whereas this prey category made up only an intermediate portion of sympatric charr diets (11%–29%). Examination of available prey composition in stream drifts showed that the consumption of terrestrial invertebrates by allopatric charr and sympatric salmon was approximately twice as much as that by sympatric charr. The presence of salmon, a potential competitor, may alter the diet of charr in the sympatric reaches. Charr holding focal points closer to the streambed were considered less efficient than sympatric salmon in their utilization of terrestrial invertebrates drifting primarily on the stream surface, although the foraging microhabitat of the charr was not influenced by the salmon. The mechanisms responsible for the dietary divergence between sympatric charr and salmon are probably the consequence of scramble competition over terrestrial invertebrates drifting on the stream surface.