The characteristics of successful invaders often include generalist traits that enable adaptation to new environments through plastic responses, including their diet. The use of trophic resources of invasive driftwood catfish Trachelyopterus galeatus of the Upper Parana River basin, Brazil, were studied with diet analysis and stable isotopic niche metrics based on δ15N and δ13C to test differences between a free-from-dam and damming population, and between wet and dry season. Stomach content analyses revealed significant differences between the populations. The diet of the riverine free-flowing river population was macroinvertebrate dominated, with Coleoptera and Lepidoptera prominent. In the damming population, diet was largely plant based, although Coleoptera was also prominent. Trophic niche breadth comparisons revealed a larger niche in the free-from-dam population versus the damming population that was independent of season. In both sites had dietary differences between the wet and dry season according to stomach contents analyses, although these were less prominent according to stable isotope metrics. Therefore, the diet of this invader is relatively general and plastic, enabling their exploitation of the varying availability of food resources between free-from-dam and damming river sections, and between wet and dry season.

中文翻译：

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巴西新热带河流域入侵性浮木鲶鱼 Trachelyopterus galeatus 饮食的季节性和栖息地变化

成功入侵者的特征通常包括通才特征，这些特征能够通过塑料反应（包括他们的饮食）来适应新环境。通过饮食分析和基于 δ15N 和 δ13C 的稳定同位素生态位指标，研究了巴西上巴拉那河流域入侵浮木鲶鱼 Trachelyopterus galeatus 营养资源的利用，以测试无坝种群和筑坝种群之间的差异，以及在雨季和旱季之间。胃内容分析揭示了人群之间的显着差异。河流自由流动的河流种群的饮食以大型无脊椎动物为主，以鞘翅目和鳞翅目为主。在筑坝种群中，饮食主要以植物为基础，尽管鞘翅目也很突出。营养生态位宽度的比较显示，与不受季节影响的筑坝种群相比，无坝种群具有更大的生态位。根据胃内容物分析，这两个地点在湿季和干季之间存在饮食差异，尽管根据稳定同位素指标，这些差异不那么明显。因此，这种入侵者的饮食相对一般和可塑性，使它们能够利用无坝和筑坝河段之间以及雨季和旱季之间不同的食物资源可用性。