Effects of ocean acidification on life parameters and antioxidant system in the marine copepod Tigriopus japonicus

Ocean acidification (OA) is caused by alteration of global ocean carbon chemistry due to the increased pCO(2) in the atmosphere and caused deleterious impacts on the marine ecosystem. Although various detrimental effects of OA were reported in marine organisms, the potential impact of OA on aquatic invertebrates still remains largely unknown. Here, we examined changes in life parameters and antioxidant system in response to low pH (7.5 and 7) in the marine copepod Tigriopus japonicus. Exposures to lower pHs (pH 7.5 and 7.0) of copepods resulted in lengthening of the developmental time with decreased fecundity and body length. Also, they showed increased reactive oxygen species contents with enhanced glutathione S-transferase and glutathione reductase activities but decreased glutathione peroxidase and superoxide dismutase activities in pH-dependent manner, indicating that OA exposure caused disturbance of the redox system in T. japonicus. Among several oxidative stress-related genes, GSTs2b was significantly up-regulated in response to OA. These findings will be helpful for a better understanding on the potential impact of OA on life parameters and antioxidant system in the marine copepod T. japonicus.