Population genetics of the oyster Crassostrea corteziensis in the Gulf of California

The native oyster Crassostrea corteziensis is a cultured species along the Mexican Pacific with considerable growth potential. For this reason CIBNOR is working towards obtaining greater knowledge that can be used in the future to begin a selective breeding program. To take advantage of the potential of using multiple populations, the genetic diversity and structure of the wild population was analyzed. Samples were obtained from five sites from Sonora to Nayarit in the Gulf of California (Mexico). Allozyme analysis showed high gene flow in the area, indicating no genetic structure. High genetic diversity was also observed, indicating an adequate potential for selective breeding and species recovery management. Allozyme and mitochondrial DNA analyses revealed the presence of a sympatric species, presumably C. columbiensis, which was found at one of the collection sites instead of C. corteziensis. Further ecological and molecular studies on both species are recommended to understand the relationships between them and the environment.