Zooplankton of the lake Jaisamand was represented by 50 taxa out of which 22 were Rotifera, 18 Cladocera, 5 Protozoa, 3 Copepoda and 2 Ostracoda. The total zooplankton exhibited n bimodal pattern with the first peak occurring in December and the second of a little less magnitude in June. The perennial zooplankters were Kerutella valgo, Brachionus jalcatus from Rotifera, Cerioduphnia spec. from Cladocera and Me8ocydops and Heterocyclops spp. from Copepoda. Considering surface zooplankton as a whole, Rotifera dominated the planktonic biomass followed by Copepoda, Cladocera, Ostracoda, Protozoa and Insecta. The species composition of the mid-stratum zooplankton was not much different from that of the surface. Interestingly, there was a presence of Cladocera in the anoxic bottom waters. The low and occasional presence of Calanoid copepods, the abundance of Cyclopoids and Cladocerans point to the eutrophication in the lake.
'l'he lake .laisamand, situated 54 kin south vast of Udaipur a t the latitude of 24' 14' N and the longitude of 73' 57' E, is the oldest man-made lake in India. The lake Jaisamand commands a total catchment area of about 1127 h i ? , almost all of which 12*