Teleosts are the largest class of bony fishes and account for more than 90% of fish species. Their reproductive systems are the key feature to adopt gradual evolutionary change under aquatic environmental conditions. Aquatic ecosystems are faced with a serious threat to their proliferation due to the discharge of untreated industrial effluents into them. Here, scanning electron microscopy (SEM) was used to examine the damaged ovaries of the freshwater fish Rohu, Labeo rohita (Hamilton-Buchanan), due to their exposure to different heavy metals in the polluted waters of Harike Wetland in Punjab, India. Deformed oocytes with rough and distorted surfaces were observed in SEM. Microscopic analysis showed that environmental pollution caused by municipal effluents had damaged the microstructural surface on the fish ovaries. Energy-dispersive X-ray spectroscopy also showed damage of the microstructural surface and an abnormal deposition of heavy metals. The alterations in the reproductive system of the fish appeared to be the most responsive and a reliable indicator of environmental pollution, which indicates their significance in aquatic biomonitoring systems. This is the first report in North India showing tissue level markers in biomonitoring programs using the ovary of Labeo rohita as the model system. Microscopic analysis showed that environmental pollution caused by municipal effluents damaged the microstructural surface of the fish ovaries.

中文翻译：

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Labeo rohita (Hamilton-Buchanan) 卵巢的超微结构和元素组成的变化作为印度 Harike 湿地 (拉姆萨尔遗址) 的污染指标

硬骨鱼是最大的硬骨鱼类，占鱼类的 90% 以上。它们的生殖系统是在水生环境条件下逐渐进化变化的关键特征。由于未经处理的工业废水排放到水生生态系统中，水生生态系统的增殖面临严重威胁。在这里，扫描电子显微镜 (SEM) 用于检查淡水鱼 Rohu、Labeo rohita (Hamilton-Buchanan) 受损的卵巢，因为它们在印度旁遮普邦的 Harike 湿地受污染的水域中暴露于不同的重金属。在 SEM 中观察到具有粗糙和扭曲表面的变形卵母细胞。微观分析表明，城市污水造成的环境污染已经破坏了鱼类卵巢的微结构表面。能量色散 X 射线光谱还显示出微结构表面的损坏和重金属的异常沉积。鱼类生殖系统的变化似乎是环境污染最敏感和最可靠的指标，这表明它们在水生生物监测系统中的重要性。这是印度北部第一份使用 Labeo rohita 的卵巢作为模型系统的生物监测项目中显示组织水平标记的报告。微观分析表明，市政污水造成的环境污染破坏了鱼类卵巢的微观结构表面。鱼类生殖系统的变化似乎是环境污染最敏感和最可靠的指标，这表明它们在水生生物监测系统中的重要性。这是印度北部第一份使用 Labeo rohita 的卵巢作为模型系统的生物监测项目中显示组织水平标记的报告。微观分析表明，市政污水造成的环境污染破坏了鱼类卵巢的微观结构表面。鱼类生殖系统的变化似乎是环境污染最敏感和最可靠的指标，这表明它们在水生生物监测系统中的重要性。这是印度北部第一份使用 Labeo rohita 的卵巢作为模型系统的生物监测项目中显示组织水平标记的报告。微观分析表明，市政污水造成的环境污染破坏了鱼类卵巢的微观结构表面。