Synecology of rotifers in a tropical flood plain lake of upper Assam

Rotifera (37 species) comprised dominant qualitative component of zooplankt on of Samuajan beel. Littoral and limnetic communities included 35 and 33 s pecies, indicated monthly richness of 4-16 and 9-16 species and registered 17.4 - 71.4 % and zero - 84.2 % community similarities. The former reflecte d abundance ranging between 17 and 138 ind./l (57 +/- 34 ind./litre), depic ted bimodal pattern and comprised between 17.1-71.4 % of total zooplankton. Limnetic rotifers (16-167 ind./litre; 54 +/- 42 ind./litre) comprised betw een 14.3 and 69.6 % of zooplankton and indicated trimodal pattern. Comments are made on temporal variations in the rotifer abundance and on the factor s influencing their production.