A Comparison of the Biochemistry and Physiology of the Eastern Oyster, Crassostrea virginica, and the Asian Oyster, Crassostrea ariakensis

Abstract

The Chesapeake Bay Foundation, US Environmental Protection Agency, and the Chesapeake Bay Commission, requested research on the introduction of the Asian oyster, Crassostrea ariakensis, to help restore the fishery and ecosystem function of the native Eastern oyster, Crassostrea virginica. In order to augment the role of C. virginica in Chesapeake Bay, C. ariakensis will likely require tolerances to low dissolved oxygen similar to that of the native oyster. This research showed that triploid and diploid C. virginica lived significantly longer than C. ariakensis under anoxic conditions, although the oxygen consumption rates of diploid oysters did not differ between species. Free amino acid pools in the gill tissue of oysters exposed to normoxia or hypoxia were analyzed. Alanine increased in both species during hypoxia, indicating the use of alternative metabolic pathways. Aspartate was consumed by C. virginica during hypoxia, confirming the use of a pathway coupling glucose and aspartate fermentation. Differences in the free amino acid pools of these two species suggest an explanation for the disparity in anaerobic metabolism between C. ariakensis and C. virginica.