Perkinsus marinus IN Crassostrea gigas AND Chione fluctifraga FROM KINO BAY, SONORA, MEXICO

*Autor para envío de correspondencia: José Manuel Grijalva-Chon Correo electrónico: [email protected] Recibido: 22 de mayo de 2014 Aceptado: 05 de octubre de 2014 ABSTRACT At present, the Pacific oyster Crassostrea gigas is the most cultivated shellfish in northwest Mexico. Nonetheless, other mollusks species such as the black clam Chione fluctifraga, which can be found along with cultured C. gigas in Sonora, represents a profitable emerging fishery resource. Since 1997, the oyster industry along the Gulf of California has been affected by severe mortality episodes disturbing almost all the farming areas. In order to evaluate the prevalence of Perkinsus marinus, a monthly sampling of 30 oysters and 30 clams was carried out during a one-year period. A total of 360 oysters and 360 clams were analyzed by Ray’s fluid thyoglicolate medium (RFTM) and PCR. The RFTM assay showed prevalence ranging from 3.3 to 60% for both oysters and clams through the study period, with infection levels from light to moderate, according to the Mackin scale. The PCR analysis was positive to P. marinus in the only one C. gigas with moderate infection in the RFTM analysis. The resulting sequence revealed 100% identity with the ITS region of P. marinus. To our knowledge, this is the first indication of Perkinsus sp. in the C. fluctifraga clam.