Vertical diurnal migration of Daphnia cucculata and Eudiaptomus graciloides in eutrophic Frederiksborg Castle Lake, Denmark

Abstract

In euthrophic Frederiksborg Castle Lake, Berg & Nygaard were the first to study vertical migration. They obtained water samples at various time intervals over several days and concluded that the bulk of the population of the zooplankton they were studying shifted from one depth to another. D. cucculata and E. graciloides are the two most dominant zooplankters in Frederiksborg Castle Lake. The vertical migration of these species was studied, and the observations are reported in this paper.