Biological Research Laboratory, Post-Graduation Program in Conservation of Cerrado Natural Resources, Goiano Federal Institute - Urutaí Campus, Urutaí, GO, Brazil.
Biological Research Laboratory, Post-Graduation Program in Conservation of Cerrado Natural Resources, Goiano Federal Institute - Urutaí Campus, Urutaí, GO, Brazil.
Sci Total Environ. 2020 Nov 10;742:140217. doi: 10.1016/j.scitotenv.2020.140217. Epub 2020 Jun 27.
The potential transfer of microplastics (MPs) between vertebrates belonging to the same taxonomic group, and the impact of such a transfer on higher trophic levels remains little explored. An experimental food chain with two fish species was installed to test the hypothesis that polyethylene MPs (PE MPs) can accumulate in animals and cause behavioral, mutagenic and cytotoxic changes at upper trophic levels. Poecilia reticulata fry were exposed to MPs for 48 h and, subsequently, offered (as food) to Danio rerio adults for 10 days to simulate an upper level food chain. PE MPs quantification in fry and in different Danio rerio tissues evidenced their accumulation at the two assessed trophic levels. This finding suggested their absorption, adherence and translocation from one organism to another. The accumulation seen in D. rerio directly exposed to MPs was associated with behavioral disorders at upper trophic level. These animals presented behavior suggestive of anti-predatory response deficit when they were confronted with a potential aquatic predator (Geophagus brasiliensis). This finding was inferred through lower school cohesion, shallower school depth and shorter distance from the potential predator. In addition, animals exposed to MPs recorded higher nuclear abnormality rates and changes in the size and shape of erythrocytes and in their nuclei; this outcome has suggested mutagenic and cytotoxic effects, respectively. Based on the current results, MPs are transferred through a food chain that only involves two vertebrates. MPs enter the vertebrates' organs, change their behavior and induce mutagenic and cytotoxic processes in animals, which can cause significant ecological consequences in freshwater ecosystems.
微塑料（MPs）在同一分类群的脊椎动物之间的潜在转移，以及这种转移对更高营养级的影响仍鲜有研究。建立了一个包含两种鱼类的实验食物链，以检验以下假设，即聚乙烯 MPs（PE MPs）可以在动物体内积累，并在上层营养级引起行为、致突变和细胞毒性变化。将罗非鱼幼鱼暴露于 MPs 中 48 小时，然后用其投喂成年斑马鱼 10 天，以模拟上层食物链。PE MPs 在幼鱼和不同斑马鱼组织中的定量表明它们在两个评估的营养级中积累。这一发现表明它们可以从一个生物体吸收、附着和转移到另一个生物体。在直接暴露于 MPs 的斑马鱼中观察到的积累与上层营养级的行为障碍有关。当这些动物面对潜在的水生捕食者（G. brasiliensis）时，它们表现出行为异常，表现出捕食防御反应不足。这一发现是通过较低的群体凝聚力、较浅的群体深度和与潜在捕食者的较短距离推断出来的。此外，暴露于 MPs 的动物记录到更高的核异常率以及红细胞大小、形状和核的变化；这分别表明了致突变和细胞毒性作用。根据目前的结果，MPs 通过仅涉及两种脊椎动物的食物链进行转移。MPs 进入脊椎动物的器官，改变其行为，并在上层营养级的动物中引起致突变和细胞毒性过程，这可能对淡水生态系统造成重大的生态后果。
