Vegetos

Abstract

Present communication deals with the phytoplankton community, their diversity, distribution during different seasons in Ranchi Lake and their correlation with physico-chemical properties of the water. Study reveals the presence of 126 algal taxa belonging to 58 genera. The recorded genera were represented by five algal groups viz. Cyanophyceae, Chlorophyceae, Bacillariophyceae, Euglenophyceae and Dinophyceae. Study reveal 12 genera and 29 species from Cyanophyceae, 34 genera and 77 species from Chlorophyceae, 7 genera and 7 species from Bacillariophyceae, 2 genera and 9 species from Euglenophyceae and 3 genera and 4 species from Dinophyceae. Based on the percentage composition, algae belonging to Cyanophyceae (61%) occupied dominant position followed by Chlorophyceae (33%), Bacillariophyceae (3%), Euglenophyceae (2%), and Dinophyceae (1%). All the above five groups of phytoplankton have a marked alteration and distribution in the lake water. Shannon Weaver index, Evenness index and index of Dominance showed the highest value in the winter season and the least value in the summer season. The Species Richness index value was minimum in the summer season and maximum during the rainy season. The study further exhibits that the phytoplankton show summer peak in March- April and winter peak in September-October.