Ocean acidification from the uptake of anthropogenic CO2 is expected to have deleterious consequences for many marine animals. Forecasting the vulnerability of these organisms to climate change is linked to an understanding of whether species possess the physiological capacity to compensate for the potentially adverse effects of ocean acidification. We will carry out a microarray-based transcriptomic analysis of the physiological response of the white leg shrimp, Penaeus vannamei to CO2-driven seawater acidification. This analysis consist in screening thousand of genes to detect which physiological functions are affected through changes in genetic expression. P. vannamie was chosen as potential model because as subtropical specie the effect of ocean warming can also be evaluate, calcium carbonate is part of the shrimp exoeskeleton and the implication of biomineralization of other key calcifaying marine animals can be inferred, ecdysis makes crustacean vulnerable to ocean change and the effect of other invertebrates can be indirect evaluated and, P. vannamei genoma project is an outgoing research and genomics tools such as microarray can be used. In lab-based cultures, organism will be raised under conditions approximating current ocean pH conditions and at projected, more acidic pH conditions in seawater aerated with CO2 gas. Genomics-based studies, such as the one proposed, have the potential to identify potential ‘weak links' in physiological function that may ultimately determine an organism's capacity to tolerate future ocean conditions.