Zooplankton fauna of Asartepe Dam Lake (Ankara, Turkey) was surveyed and forty-eight taxa were recorded by collecting samples in three different seasons (Autumn 2007, Spring and Summer 2008).
Species richness of Rotifera was found high (43), while species richness of Cladocera (3) and Copepoda (2) was found low (Table 1). One of these rotifers, Encentrum felis, is a new record for Turkey. Twentyeight taxa were observed in autumn and spring, but 34 taxa were observed in summer. Twelve taxa were seen together in three seasons, while twenty-two taxa were seen in only one season. Some water parameters (pH, dissolved oxygen, electrical conductivity and watertemperature) were measured during field trips (Table 2).