Trophic relationships of nonnative brown trout, Salmo trutta, and native Bonneville cutthroat trout, Oncorhynchus clarkii utah, in a northern Utah, USA river
Trophic relationships of nonnative brown trout, Salmo trutta, and native Bonneville cutthroat trout, Oncorhynchus clarkii utah, in a northern Utah, USA river
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美国犹他州北部河流中非本地褐鳟鱼 Salmo trutta 和本地邦纳维尔切喉鳟鱼 Oncorhynchus clarkii utah 的营养关系
DOI：
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发表时间：
2007
影响因子：
1.4
通讯作者：
E. VanDyke
中科院分区：
文献类型：
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作者：
Peter Mchugh;P. Budy;G. Thiede;E. VanDyke
外来鳟鱼的入侵导致了北美西部切喉鳟鱼种群的普遍下降。与其他非本地鲑鱼相反，非本地褐鳟鱼在本地切喉鳟鱼数量下降中的作用人们知之甚少。具体而言，这些物种之间的生态相似性水平和其他营养机制的重要性（例如，捕食）的相互作用是关键的不确定性。我们评估了营养关系的褐鳟鱼和切喉鳟鱼在北方犹他州河流使用饮食和稳定同位素分析相结合。我们使用多种互补措施比较了这两个物种的饮食习惯。基于胃内容物和δ 13 C特征，我们发现这些物种消耗了类似的机会主义饮食（即，它们在觅食模式上没有选择性）。然而，在大多数尺寸下，褐鳟鱼摄取更大的猎物-包括鱼类-并占据更高的相对营养位置（即，δ 15 N）比切喉鳟高。总的来说，这些结果表明了高度的饮食相似性，因此加强了早期的结论，这两个物种之间的种间竞争。我们的研究，当与其他人的工作一起考虑时，表明这些物种之间存在捕食性相互作用的潜力（即，捕食小的割喉鳟鱼的褐鳟鱼）。我们认为，未来的研究褐鳟鱼，割喉鳟鱼的相互作用应该考虑更详细的捕食效应。
Nonnative trout invasions have caused the widespread decline of cutthroat trout populations in western North America. In contrast to other nonnative salmonids, the role of nonnative brown trout in native cutthroat trout decline is poorly understood. Specifically, the level of ecological similarity that occurs between these species and the importance of other trophic mechanisms (e.g., predation) in their interactions are key uncertainties. We evaluated the trophic relationships of brown trout and cutthroat trout in a northern Utah river using a combination of diet and stable isotope analyses. We compared the dietary habits of these two species using multiple and complementary measures. Based on both stomach contents and δ13C signatures, we found that these species consumed a similar and opportunistic diet (i.e., they were nonselective in their foraging patterns). However, at most sizes, brown trout ingested larger prey—including fishes—and occupied a higher relative trophic position (i.e., δ15N) than cutthroat trout. Overall, these results demonstrate a high degree of dietary similarity and therefore strengthen earlier conclusions regarding interspecific competition between these two species. Our study, when considered alongside the work of others, suggests there is potential for predatory interactions between these species (i.e., brown trout preying on small cutthroat trout). We believe that future research on brown trout–cutthroat trout interactions should consider predatory effects in greater detail.