Najeeb Ahmad Bhat Ashwani Wanganeo Parvaiz Ahmad Bhat Rajni Raina Proceedings of the International Academy of Ecology and Environmental Sciences ISSN 2220-8860 http://www.iaees.org/publications/journals/piaees/online-version.asp 2013 3 3 238 246 09/2013 International Academy of Ecology and Environmental Sciences Cladocera Copepoda diurnal migration Bhoj wetland The diurnal dynamics of the vertical distribution of zooplankton was studied in Bhoj Wetland, Bhopal. Vertical distribution of the zooplankton community in general showed a clear diurnal variation in the water column of a typical stratified lake. Zooplankton concentration was found to be high at the surface layer during night hours with peak abundance around the middle of the night and another peak was observed just before sunrise, followed by a rapid nadir after sunrise. Zooplankton can offset the loss of daytime foraging opportunity by moving up into the water column to graze at night, when predation by visual predators is greatly reduced and it can be also attributed to light intensity which is responsible for vertical migration during the twenty four hour cycles. Among different classes, cladocerans and the copepod showed nocturnal migration conversely rotifers, had a relatively uniform distribution throughout the water column Out of the twenty three species, Bosmina species and Cyclops species ascended at night and descended during day hours, however, Keratella cochlearis showed uniformity in distribution throughout the water column during the study. DOI 10.0000/issn-2220-8860-piaees-2013-v3-0020 http://www.iaees.org/publications/journals/piaees/articles/2013-3(3)/diurnal-variation-of-zooplankton.pdf