Owning to dissimilarity with native macrophytes, invasive macrophytes may negatively affect the diet and foraging efficiency of fishes. We evaluated the invertebrate availability, diet composition, and foraging efficiency of four fish species that use macrophytes as habitat in a native and a highly invasive macrophyte. The samples were taken in a reservoir in Brazil (22° 33′ S, 52°54′ W). We collected invertebrates and fishes simultaneously in macrophyte stands dominated by the invasive Poaceae Urochloa arrecta and the native Eichhornia azurea . We evaluated the foraging efficiency by the total number of prey consumed and by the degree of stomach fullness. We used an approach based on resampling procedures to compare differences in composition of invertebrates, composition of fish diet, and the similarity between invertebrates and fish diet. The abundance of invertebrates and the diet composition differed significantly between plants. On the other hand, fish foraging efficiency did not differ between macrophytes. Despite this lack of difference of foraging efficiency, the lower abundance of food items in the invasive macrophyte and the significant changes in fish diet suggest that U. arrecta is not a favorable feeding habitat for fishes, compared to the native E. azurea .

中文翻译：

---

饲养栖息在新热带水库中的原生和非原生大型植物群落的鱼类

由于与本地大型植物的不同，入侵的大型植物可能会对鱼类的饮食和觅食效率产生负面影响。我们评估了四种鱼类的无脊椎动物可用性、饮食组成和觅食效率，这些鱼类使用大型植物作为原生和高度入侵大型植物的栖息地。样品取自巴西的一个水库（南纬 22° 33 分，西经 52 度 54 分）。我们同时在大型植物群中收集了无脊椎动物和鱼类，这些植物群主要是入侵的禾本科 Urochloa arrecta 和本地的 Eichhornia azurea。我们通过消耗的猎物总数和胃饱胀程度来评估觅食效率。我们使用基于重采样程序的方法来比较无脊椎动物组成、鱼类饮食组成以及无脊椎动物与鱼类饮食之间的相似性的差异。无脊椎动物的丰度和饮食成分在植物之间存在显着差异。另一方面，大型植物之间的鱼类觅食效率没有差异。尽管觅食效率没有差异，但侵入性大型植物中食物的丰度较低以及鱼类饮食的显着变化表明，与原生 E. azurea 相比，U. arrecta 不是鱼类的有利觅食栖息地。