Abstract：
Fish are excellent bioindicators and can reveal the presence of plastic in the environment. Diagnosing the composition and abundance of polymers in the fish diet makes it possible to evaluate their point sources and possible trophic transfers. We aimed to use the gastrointestinal contents of Poecilia reticulata in subtropical urban streams to detect the occurrence, shape, color, size, and chemical composition of polymers. For this, the diet of 240 individuals was analyzed using the volumetric method, and the microplastics (MPs; < 5 mm) recorded were characterized using Raman spectroscopy. Individuals predominantly consumed organic detritus and aquatic macroinvertebrates, with higher proportions of Diptera. A total of 111 plastic particles (< 0.5 to 12 mm) were recorded, and a subset of 14.4% was subjected to a micro-Raman spectrometer (830 nm excitation). The occurrence of polyethylene terephthalate (PET) and polypropylene (PP) with phthalocyanine dye was recorded. Some fragments could not be identified by Raman, but they contained indigo blue dye. Poecilia reticulata had a predominantly detritivorous diet with a record of plastic consumption, reflecting environmental pollution. Our results demonstrate that individuals of P. reticulata have ingested MPs in urban streams. This reinforces the need for future studies on the relationship between the presence of MPs in fish and the level of pollution in streams, comparisons with species of different feeding habits, and the potentially harmful effects on the entire biota.
摘要：
鱼是优秀的生物指标，可以揭示环境中塑料的存在。诊断鱼类饮食中聚合物的组成和丰度可以评估它们的点源和可能的营养转移。我们的目的是利用亚热带城市溪流中网纹Poeciliareticulata的胃肠道内容物来检测这种情况。形状,颜色,尺寸,和聚合物的化学成分。为此，用容量法分析了240名个体的饮食，使用拉曼光谱表征记录的微塑料(MPs;<5mm)。个人主要消耗有机碎屑和水生大型无脊椎动物，双翅目的比例较高。总共记录了111个塑料颗粒（<0.5至12毫米），对14.4%的子集进行显微拉曼光谱仪(830nm激发)。记录了具有酞菁染料的聚对苯二甲酸乙二醇酯（PET）和聚丙烯（PP）的发生。一些碎片无法通过拉曼识别，但里面有靛蓝染料.网纹Poecilia的饮食主要是有害的，有塑料消耗的记录，反映环境污染。我们的结果表明，网状鱼腥草的个体在城市溪流中摄入了MP。这加强了对鱼类中MP的存在与溪流污染水平之间关系的未来研究的需要，与不同摄食习惯的物种进行比较，以及对整个生物群的潜在有害影响。
