Some observations of zooplankton composition and abundance in river Damodar during winter season.

Abstract

The investigation has been made to examine the hydrological condition of the studied area (some physicochemical parameter of water, zooplankton community and its diversity).During the study it was observed that the trend of variation of water temperature was from 15.9ºc to17.5ºc. pH was found to alkaline ranging from 8.5 to 9.1.During the study there was afluctuation in O2levelfrom 3.2 mg/lit. to 5.2 mg/lit.Free CO2 was found to be higher throughoutthe study with a variation from 14 to 18 mg/lit.In the study of Zooplankton,Cladocera and Rotifera were chiefly present comprising mostly of Daphniasp, Rotariasp., Brachionussp.and Cyclopsspp. Besides theae groupsof speciesCopepoda was also present.A total of 10 genera includingone larval form were found during study. Among 10 genera only 5were dominant ( Daphniasp., Rotariasp., Brachionus sp., Mesocyclopssp.and nauplius larvae), within these dominant species the most dominant wereDaphniasp., Rotaria sp.and Brachionus sp.which occur more than three times during study.While the community study was concerned it was foundthatthe species richness ranged from 0.734 to 1.17, Evenness from 0.911 to 0.975and Shannon-Wiener index value was varied between 1.85 and 2.43. The mean values of them were0.924, 0.939and 2.25respectively.