Analysis of the inland cladocerans of Flanders (Belgium) – Inferring changes over the past 70 years

The four crustacean orders of the cladocerans repre-sent, together with copepods and rotifers, the most com-mon zooplankton taxa in all types of lentic freshwater bodies (1). They exhibit a parthenogenetic (clonal) repro-duction mode during periods of favourable environmental conditions, and produce sexual dormant eggs (ephippia) when conditions deteriorate (2). As such they are capable of remaining dormant in the habitat for decades (3). Because of their capacity for rapid population growth, some pelagic members of the group (especially the large-bodied Daphnia and Diaphanosoma) are able of keeping water bodies in a clear water state by grazing down the phytoplankton (4). Most species feed on bacteria, protists, periphyton, and detritus (many chydorids and macrothric-ids), some are parasitic (e.g. Anchistropus on the poly