The effects of the decline in ocean pH,termed as ocean acidification (OA) due to elevated carbondioxide,on calcifying organisms such as marine crustacean are unclear yet.To understand the effectof lower pH levels on the physiological responses of a marine crustacean brine shrimp,Artemiasinica,the animals were raised for two weeks at different pH levels ranging from 8.2 to 7.6 followed byproteomics and fatty acids determination.