CO2 acidification and its differential responses on aquatic biota – a review

•Anthropogenic CO2 emission along with other stressors influences climate change.•Ocean acidification decreases the saturation state and the shallowing carbonate saturation depth in ocean bodies.•Increase in acidification stressor influence strong selection pressure on traits for fitness and evolutionary change.•Responses to CO2 exposure are species-specific.•Acclimation and adaptation strategies induce physiological and genetic responses to acidification stressor.