The River Yamuna emerges from Saptarishi Kund, Yamunotri and merge with River Ganges at Allahabad, India. Anthropogenic stress has affected the water quality of the river Yamuna drastically in the stretch traversing Delhi and its satellite towns (National Capital Region, NCR). In the present study, effect of water quality on the microbial life in the River Yamuna was analyzed using ciliate communities (Protista, Ciliophora) as bio-indicators. Water samples were collected from six sampling sites chosen according to the levels of pollution along the river and water quality was analysed using standard physicochemical factors. As the river traverses Delhi NCR, water quality deteriorates considerably as indicated by the Water Quality Index at the selected sampling sites. Seventy-four ciliate species representing nine classes were recorded. Based on the Shannon diversity index, maximum species diversity was found at the point where the river enters Delhi. The saprobity index showed the river water was beta-mesosaprobic when the river enters Delhi and alpha-mesosaprobic at downstream sites after the first major drain outfall. Significant relationship between the spatial variation in ciliate communities and abiotic parameters indicate that ciliates can be used as effective bioindicators of pollution in the River Yamuna.

Yamuna河从Yamunotri的Saptarishi Kund涌出，并与印度阿拉哈巴德的恒河合并。在穿越德里及其附属城镇（国家首都地区，NCR）的人行道上，人为压力极大地影响了亚穆纳河的水质。在本研究中，使用纤毛虫群落（Protista，Ciliophora）作为生物指标，分析了水质对亚穆纳河微生物生活的影响。根据沿河的污染水平从六个采样点采集水样，并使用标准理化因子分析水质。由于这条河流流经德里NCR，因此水质大大恶化，如所选采样点的水质指数所表明的那样。记录了代表9类的74种纤毛虫。根据香农多样性指数，在河流进入德里的地点发现了最大的物种多样性。腐烂指数显示，当河流进入德里时，河水是β-中异波的，而在第一次主要排水口之后，河水在下游站点是α-中异波的。纤毛虫群落的空间变化与非生物参数之间的显着关系表明，纤毛虫可以用作亚穆纳河污染的有效生物指标。