Seasonal Variations and Diversity of Planktons in River Rapti at Gorakhpur

The paper deals with occurrence and biodiversity of planktons in river Rapti observed through out the year. During the study period total 47 species were observed of which 29 were of phytoplanktons belonging to 4 families: Bacillariophyceae (11), Chlorophyceae (10), Cyanophyceae (6) and Euglenophyceae (2) and 18 of zooplanktons including Protozoa (6), Rotifera (4), Cladocera (3), Copepoda (4) and Ostracoda (1). The total number of planktons in summer season exceeded that of in winter and lowest number of planktons was recorded during monsoon.