Temperature effects on the feeding and electron transport system (ETS) activity of Gammarus fossarum

The effects of an increase in water temperature as a direct consequence of global change on organisms living in springs and spring brooks have rarely been studied in laboratory experiments. In this study, experiments were conducted to test the response of Gammarus fossarum Koch, 1836, as an abundant representative of the European spring fauna, to changing water temperatures. The aim was to find out experimentally how G. fossarum reacts to varying and increasing water temperatures. The experiments were conducted in flow channels with spring water. In each flow channel, G. fossarum were placed in boxes with a flow-through system for 4 weeks. Two analytical methods were applied: the feeding activity of the amphipods was quantified in order to determine the reaction of G. fossarum on the level of the organism and the respiratory electron transport system (ETS) assay was conducted in order to determine changes in the test organisms on the cellular level. The results show that the feeding activity of G. fossarum increased with increasing water temperature, up to an optimum, indicating an increase in their metabolic activity. The ETS activity does not show significant differences at the different temperatures tested. A possible explanation for this is the ability of the organisms to adapt quickly to the changed environmental circumstances.