The process of urbanisation is increasing the frequency and magnitude of fluctuations in the availability of food resources for fish. In this study, we investigated whether the diet and prey selected by the guppy Poecilia reticulata reflect the different levels of urbanisation using the total area of impervious surface soil as the metric. Rural streams (low percentage of urbanisation—LPU) and urban streams (high percentage of urbanisation—HPU) were sampled during both the rainy and dry seasons. The hypothesis tested was that the diet and selective behaviour differ spatially and seasonally between LPU and HPU streams. Among the analysed items, seasonal significant differences were only observed in HPU streams. In LPU streams, the trophic spectrum was wider, and a higher diversity of prey was selected. In HPU streams, the diet richness was lower with a dominance of Chironomidae, and there was also less variability in selected prey. Ephemeroptera and Trichoptera were always avoided, but Coleoptera were avoided only in LPU, while Oligochaeta were avoided in HPU streams. Thus, the diet and prey selected by P. reticulata were different between LPU and HPU streams, and this species has potential to compete for food with the native fauna in a wide variety of environmental conditions and available resources. Therefore, this dietary flexibility probably offers competitive advantages when colonising and establishing in a new habitat.

中文翻译：

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城市化影响入侵孔雀鱼 Poecilia reticulata 的饮食和摄食选择性

城市化进程增加了鱼类食物资源可用性波动的频率和幅度。在这项研究中，我们以不透水表层土壤的总面积为指标，调查了孔雀鱼 Poecilia reticulata 选择的饮食和猎物是否反映了不同的城市化水平。在雨季和旱季对农村河流（低城市化百分比 - LPU）和城市河流（高城市化百分比 - HPU）进行采样。测试的假设是 LPU 和 HPU 流之间的饮食和选择行为在空间和季节上不同。在分析的项目中，仅在 HPU 流中观察到季节性显着差异。在 LPU 流中，营养谱更宽，选择的猎物多样性更高。在 HPU 流中，由于摇蚊科占优势，饮食丰富度较低，所选猎物的变异性也较小。蜉蝣目和毛翅目总是被避免，但鞘翅目只在 LPU 中被避免，而寡毛纲在 HPU 流中被避免。因此，P. reticulata 选择的饮食和猎物在 LPU 和 HPU 流之间是不同的，并且该物种有可能在各种环境条件和可用资源中与本地动物竞争食物。因此，这种饮食灵活性可能会在新栖息地殖民和建立时提供竞争优势。P. reticulata 选择的饮食和猎物在 LPU 和 HPU 流之间是不同的，并且该物种有可能在各种环境条件和可用资源中与本地动物竞争食物。因此，这种饮食灵活性可能会在新栖息地殖民和建立时提供竞争优势。P. reticulata 选择的饮食和猎物在 LPU 和 HPU 流之间是不同的，并且该物种有可能在各种环境条件和可用资源中与本地动物竞争食物。因此，这种饮食灵活性可能会在新栖息地殖民和建立时提供竞争优势。