Faunal diversity of Cladocera (Crustacea: Branchiopoda) in wetlands of Majuli (the largest river island), Assam, northeast India

Abstract

Our collections from the wetlands of Majuli, the largest river island of the world and a unique fluvial landform of the Brahmaputra river basin of northeast India, reveal 55 Cladocera species belonging to 36 genera. These represent ~46.0% and ~79.0% of the freshwater species and genera of the taxon known from India, respectively. The Indo-Chinese Alona kotovi is new record from India and the Indo-Chinese Chydorus angustirostris is new to northeast India. The Australasian Disperalona caudata, the Indo-Chinese Alona cheni, and the Oriental Celsinotum macronyx and Kurzia (Rostrokurzia) brevilabris are other biogeographically notable elements while several species are of regional interest. The speciose and diverse Cladocera reflect habitat diversity and environmental heterogeneity of the sampled ecosystems. The fauna records rich diversity of the littoral-periphytonic taxa in general and the Chydoridae in particular. Majuli Cladocera is characterized by lack of Leydigiopsis, Daphnia spp. and Acroperus harpae; fewer Diaphanosoma spp., and uncommon occurrence of the Bosminidae and Moinidae as compared with our samples elsewhere from the floodplains of the Brahmaputra basin.

Keywords

• Biodiversity
• Brahmaputra basin
• fluvial floodplain
• distribution
• Cladocera biogeography.