The aim of this study was to examine relations between the density and species richness of rotifers and environmental factors in 55 small water bodies in the Wielkopolska region. Canonical correspondence analysis (CCA) revealed that typically pelagic rotifers (species of the genera Brachionus, Keratella, or Polyarthra) occurred in larger and deeper reservoirs in conjunction with open water and helophytes. Their distribution was conditioned by the presence of fish, by the lack of overshading, and high concentrations of phosphorus. Littoral rotifers (Cephalodella, Lecane, or Lepadella) were typical of small surface and shallow ponds and of areas with a high degree of spatial complexity – elodeids. They preferred fishless water bodies with strong overshading and high transparency of water. The distribution of pelagic species was dependant on high concentrations of chlorophyll a, while littoral species depended on high concentrations of dissolved organic matter.
Variance partitioning extracted the type of habitat and the associated degree of habitat heterogeny as very strong predictors of rotifer distribution in mid-field reservoirs.