Physiological response of the oyster Crassostrea gigas during an exposure and depuration period to the dinoflagellate Prorocentrum lima

Blooms caused by the dinoflagellate Prorocentrum lima produce toxins potentially harmful to human health indirectly by the consumption of mollusks. The short-term exposure and depuration period to the dinoflagellate P. lima in Crassostrea gigas was studied to know the effects induced in the physiological system. Three treatments were evaluated: control diet with 2 x 106 cell mL-1 C. muelleri; T1, oysters fed with P. lima (6 x 103 cell mL-1), and T2, oysters fed with P. lima (6 x 103 cell mL-1), and C. muelleri (2 x 106 cell mL-1), during 13 days exposure phase, followed by 15 days depuration phase. Differentiation and count of hemocyte, as well as, hemolymph parameters: protein, glucose, lactate, cholesterol, and triglycerides were examined. A significant decrease in the total hemocyte, granulocytes, and hyalinocytes count after 13 days of exposure phase was detected in the treatments with P. lima. The physiological response of C. gigas against the dinoflagellate was also affected, with significant differences in the concentration of glucose, lactate, cholesterol, and triglycerides during the trial. Experimental results suggest an affection in the physiological response of C. gigas as a result to P. lima exposure, with recuperation after 8 days with a control di