Free-living ciliated protist diversity in the freshwater ecosystems of Delhi, India

A series of investigations was carried out on the freshwater free-living ciliate fauna from sixteen sites along the Yamuna River and various freshwater bodies in the Delhi region. These studies, conducted over the past 35 years, focused on the identification and documentation of ciliate diversity based on live-cell observations and silver staining techniques. In total, 104 species were documented, both from ongoing studies and published literature, representing 9 classes, 19 orders, 38 families, and 61 genera. Of these, one species, Sterkiella multicirrata (Li et al., 2018), is a new record for the Indian fauna. A large number of Spirotrich species were identified, along with a smaller proportion of ciliates belonging to classes Heterotrichea, Litostomatea, Phyllopharyngea, Oligohymenophorea, Prostomatea, and Colpodea. The highest ciliate diversity was observed in water samples from the Okhla Bird Sanctuary (OBS). Ciliate diversity and distribution recorded have been listed along with some photomicrographs.