The biodiverse rotifer assemblages (Rotifera: Eurotatoria) of Arunachal Pradesh, the eastern Himalayas: alpha diversity, distribution and interesting features

The rich and diverse alpha diversity and biogeographic interest of Rotifera of this Himalayan biodiversity hot-spot is noteworthy in light of predominance of the small lentic ecosystems. Lecanidae> Brachionidae> Lepadellidae> Trichocercidae collectively comprise ~71% of total rotifer species. Brachionidae records the highest richness known from any state of India.

This study indicates the role of thermophiles with overall importance of ‘tropic-centered’ genera Lecane and Brachionus, and particularly at lower altitudes; species of ‘temperate-centered’ genera Keratella, Notholca and Synchaeta are notable in our collections at middle and higher altitudes, while Trichocerca and Lepadella are other species-rich genera. The rotifer fauna shows a mixture of ‘tropical’ and ‘cold-water’ elements, depicts the littoral-periphytonic character, and records a large component of cosmopolitan species.

The study of more collections from middle and higher altitudes of Arunachal Pradesh are desired for an update on Rotifera from the eastern Himalayas.