Hyperventilation and loss of hemolymph Na+ and Cl- in the freshwater amphipod Gammarus fossarum exposed to acid stress: a preliminary study.

The effect of acidification on the acid-sensitive species Gammarus fossarum was investigated in the laboratory. The results showed that as mortality increased, mean hemolymph chloride and sodium concentrations decreased rapidly. Concomitantly, organisms hyperventilated during the first 24 h and then started to hypoventilate. These results demonstrated that exposure to acid stress in the acid-sensitive species G. fossarum led to ion-regulatory and respiratory failure as previously reported in fish and crayfish exposed to acid stress.