Metabolic Rate in Hydrobionts of Different Ecological Groups in an Experiment.

The intensity of oxygen consumption and the rate of phosphorus excretion are studied in planktonic crustaceans Daphnia longispina O.F. Müller (Cladocera), benthic crustaceans Hyalella azteca (Saussure) (Amphipoda), and fish Oryzias latipes (Temminck & Schlegel) (Beloniformes) united in one trophic net in an experimental ecosystem. The highest rates of metabolic intensity are established for small organisms Daphnia longispina (7.44 ± 2.49 mgO/(g h) and 0.447 ± 0.143 mgP/(g h)). The rate of phosphorus excretion differed by an order of magnitude between hydrobionts of different ecological groups and decreased in the order planktonic crustaceans –> benthic crustaceans –> fish. It is shown that the contribution of hydrobionts to the creation of primary production depends on the biomass of a particular species. [ABSTRACT FROM AUTHOR]