As oceans and many estuaries become more acidic, identifying adaptable or nonadaptable species (“winners” or “losers”) will enable better predictions of community and ecosystem function alterations due to climate change. Marine bivalves are frequently subjects of ocean acidification (OA) research because of their perceived vulnerability, which also threatens loss of their valuable ecosystem services. Studies indicate that larvae of many broadcast spawning oyster and mussel species are physiologically sensitive to alterations in carbonate chemistry. Running counter to this trend are recent investigations of brooding oyster species (genus Ostrea) that suggest their offspring may be considerably more resistant to OA stress. Although the precise mechanism conferring OA resistance to Ostrea larvae is unknown, a strong candidate appears to be exaptation of traits developing embryos that require to cope with adverse carbonate conditions they typically encounter in the brood chamber. New and previously reported data on Ostrea brood chamber conditions are discussed in the context of OA. Novel technical and experimental approaches are offered to address current knowledge gaps in future studies.