higher abundance of cladocerans (comprising 48% of all samples) in the Prado Reservoir, where small algae are abundant (Salazar et al. 2002). Tropical and temperate limnological comparative studies have demonstrated that oligotrophic systems are dominated by copepods, whereas more eutrophic systems are dominated by rotifers and cladocerans. Nevertheless, the work by Pinto-Coelho et al. (2005) established that cladocerans and cyclopoids are associated to the more eutrophic lakes and reservoirs, which support greater crustacean abundances in most latitudes.