SEASONAL ABUNDANCE OF ZOOPLANKTON IN THE ASHTAMUDI LAKE – SOUTHWEST COAST OF KERALA, INDIASoumya Jalal and Biju A.Abstract Seasonal abundance of zooplankton in the Ashtamudi lake was studied. Monthly zooplankton samples were collected from ten different stations of the Ashtamudi lake for a period of one year from February 2018 to January 2019. Sixteen zooplankton groups viz. medusae, chaetognaths, polychaetae, copepods, decapod larvae, cladocerans, stomatopod larvae, ostracods, gastropods, mollusc larvae, mysids, amphipods, isopods, lucifer, fish egg and fish larvae were observed. Among these, copepods were the most prominent group and contribute 41.59% of the total zooplankton group. Total abundance of different zooplankton groups was about 21171796.44 No/100m3 were observed from the study area. Zooplankton abundance was maximum at S7 near the barmouth and minimum zooplankton abundance was observed at S1 near the upstream. The seasonal abundance of different zooplankton groups was maximum during pre-monsoon season (40.34%) which is followed by post-monsoon season (31.91%) and monsoon season (27.75%). Various diversity indices were also presented in this study. |