About the relationship between the zooplankton and fluctuating water levels of Lago Camaleão, a Central Amazonian várzea lake

Abstract

Throughout 1981 and 1982 a study of the composition and abundance of the three main groups of zooplankton, Rotifera, Copepoda, and Cladocera, was conducted in Lago Camaleão, an Amazonian floodplain lake. Rotifers are dominant both in terms of species numbers and abundance. Rotifers exhibit two standing-stocks peaks during the year. One, during the extreme dry season, and another at the beginning of the rising water period. The species associations of rotifers also reflect the flooding regimes - and its consequences. The extremely low standing-stock observed during the high water season is attributed mainly to prevailing poor oxygen conditions during normal floods and current during extreme floods.