3.3 Rotifera
In the present study period totally, 18 species of rotifera belonging to 7 genera were recorded (Table 2) during the period of December-2011 to November- 2012. The population density of rotifera was ranged between 648 and 1304 (ind./L) (Table 3). A maximum density of 1304 (ind./L) was noticed in April and minimum of 684 (ind./L) in October. The species dominance was found high (0.101) during October and low (0.077) in March and April. The Shannon diversity index (H) was found to be high (2.713) in March-April and low (2.528) in October. Simpson’s diversity index was maximum (0.923) during March-April while minimum (0.899) in October. The high species evenness (0.837) was found during March-April and low evenness (0.695) was noticed in October. The Margalef species richness (R1) was found maximum (2.604) in October and minimum (2.37) in April. The Menhinick index (R2) values were fluctuated throughout the study period with maximum (R2) (0.688) recorded during October and minimum (0.498) in April (Table 3).