Rotifer communities of ponds supplied with post‐waste water

Abstract

The studies concern the changes in communities of rotifers in a model system of 4 through‐flow ponds linked in a row and constantly supplied with waste‐water after mechanical‐biological treatment. Studies were carried out from the spring of 1977 to the spring of 1978 – i.e. during the first year the ponds were used.Twenty‐four species of rotifers, forming three cenotic communities differing in number of species, dominance structure and abundance, were found. Gradually increasing similarity of communities with the distance from the source of post‐waste water reflects the increasing stability of physico‐chemical and biological conditions in the examined model ecosystem.Maximum biocenotic stability was observed in the last pond with the highest specific differentiation, and also considerable share of oligo‐ and β‐mesosaprobionts, the highest frequency of species and slight differences in abundance between the dominant and accompanying species.The role of trophic factor in formation of rotifer communities in the successive links of the presented model pond system is pointed out.