The biodiverse rotifers (Rotifera: Eurotatoria) of Majuli River Island – an alluvial floodplain of Assam state (northeast India) and the largest river island

Our assessment of Rotifera biodiversity of the floodplain wetlands of the Majuli River Island of the Brahmaputra basin in Assam state, northeast India (NEI) reveals a total of ۱۷۵ species belonging to ۳۹ genera and ۱۹ families. The rich and diverse assemblages of the phylum categorize the Majuli as one of the megadiverse Rotifera region of India. The observed biodiversity of  Rotifera is hypothesized to be associated with the habitat diversity of the Majuli wetlands, including its varied aquatic macrophytes, the location of the study areas in the ‘Indo-Burmese biodiversity hotspot’ and the ‘Rotiferologist effect’, and merits conservation interest in light of the extinction threat to this alluvial floodplain. We record one rotifer species as new to the Indian sub-region and NEI, and ۲۹ species as new records from the Majuli. We also consider various newly recorded species to be of global and regional biogeography interest, with some hypothesized to have a biogeographic role linked to the ‘Assam gateway’. High richness of Lecane > Lepadella ≥ Trichocerca, the richness of Testudinella, and the paucity of Brachionus species are noteworthy features. Reports of ۱۷۵ species from floodplain lakes and ۱۴۸ species from small wetlands indicate biodiverse rotifer assemblages in these two categories of wetlands and present a useful contribution to Rotifera ecological diversity of the Indian and the tropical floodplains.

کلیدواژه ها:

Alluvial floodplain ، biodiversity ، distribution ، largest river island ، megadiverse ، wetlands