Alterations in Hemolymph Ion Concentrations and pH in Adult Daphnia magna in Response to Elevations in Major Ion Concentrations in Freshwater

Increases in the concentrations of major ions (Na⁺ , K⁺ , Ca²⁺ , Mg²⁺ , Cl^- ) in freshwater are a growing concern for ecosystem health. These increases may originate from anthropogenic activities such as road deicing, fracking spills, mining, and fertilizer application and have detrimental effects on freshwater organisms through disturbances in ionoregulation and acid-base balance. The cladoceran Daphnia magna is adapted for active ion uptake …