Characteristic features of bi-valvias’ physiology indwelling different habitats

The analysis of cardiac activity in the oyster Crossastrea brasiliana and in the soft clam Anomalocardia brasiliana indwelling the surface, the upper, and the inner layer of the ground was carried out. A considerable difference in cardiac activity of mollusks was revealed: the rate of the heart beat in oyster was 28 ± 1 beats per min, while the heart activity of the soft clam was aperiodic - from total cardiac arrest up to 12 beats per min. It is suggested that the difference in physiology of the studied clams is caused by the mollusks’ mode of life.