Successions of zooperiphyton in a small river

Abstract

In the small Latka River, which is characterized by a high heterogeneity of abiotic characteristics and a rich fauna composition, a high diversity of developing zooperiphyton structures was recorded consisting of invertebrates with short life cycles: the larvae of chironomids, caddisflies, mayflies, oligochaetes, nematodes, and other animals. One distinctive feature of seasonal and interannual zooperiphyton succession is the annual prevalence in abundance of spreading chironomid larvae of age I, which belong to the most representative dominating group of amphibiotic invertebrates, including species adapted to different saprobic conditions. The taxonomic and quantitative domination of chironomids make it possible to consider the family Chironomidae a key group in the formation of the zoocenosis structure. Under disturbed habitat conditions (pollution, rainfall floods, and the press of omnivorous invertebrates), the restoration of typical structures occurs rather quickly due to the particular features of biology in species short life cycles. However, no relative stabilization in communities was observed. This is the main difference between the sequence of succession processes in the Latka River and that observed in large water bodies (lakes and water reservoirs), where there are no strict limitations on living-space volume or food availability and abiotic conditions are more stable, thus allowing filter-feeding sessile animals (sponges, bryozoans, and zebra mussels) to develop on solid substrates. These species are able to develop multispecies consortia and form relatively stable long-term communities.