The object of this study is to understand the effect of food on the speed of ciliary movement of the gill of cultured hard clam. It is known that the speed of ciliary movement of the gill of cultured hard clam is affected by temperature and salinity, so this study explores the influence of food on speed of ciliary movement of the gill under the different temperature-salinity conditions. This study used three methods to test for the speed of ciliary movement of the gill of cultured hard clam. By the first method, using a piece of aluminum foil tested for the gill in vivo, demonstrated none of Isochysis galbana¡BSynechococcus sp.¡Btemperature¡Bphase and sizes of aluminum foil affected significantly on the speed of ciliary movement of the gill of cultured hard clam. By the second method, using sand tested for the gill in vitro, demonstrated adding I. galbana or the high concentration (1¡Ñ105 cells ml-1) of Tetraselmis chui caused the speed of ciliary movement of the gill of cultured hard clam increased significantly at room temperature, 15 psu. At 32¢J, only the low concentration(1¡Ñ103 cells ml-1) of I. galbana affected significantly the speed of ciliary movement of the gill, and the mean speed of 1.36 cm/min at 32¢J was slower than the mean speed of 2.05 cm/min at room temperature. At 10 psu, both high and low concentration of I. galbana influenced the speed of ciliary movement of the gill, besides the mean speed of 2.82 cm/min at 10 psu was faster than the mean speed at 25 psu. The ciliary movement of the gill of cultured hard clam had no response to I. galbana, and the mean speed of 1.76 cm/min at 25 psu. By the third method, using sands tested for the gill in vivo, the results showed that adding the high concentration of I. galbana caused the speed of ciliary movement of the gill of cultured hard clam to increase significantly, and 33.85¢H of the change of this speed was not different significantly with 33.00¢H of the change of the speed of the gill in vitro adding the high of I. galbana. Besides, the mean speed of 1.99 cm/min by using sands tested for the gill in vivo was not also different significantly with the mean speed of the gill in vitro.Based on the above results, the result tested the gill in vitro by the second method was similar to the result tested the gill in vivo by the third method. Under the same condition, the maximum change of speed of ciliary movement of the gill was about sixty percent from the experiment of adding the low concentration of I. galbana, and the minimum change of speed was about ten percent from the experiment of the low concentration of T. chui. The change of the speed of ciliary movement of the gill of cultured hard clam was most affected by I. galbana, and the change was about thirty percent.

Abstract The combinations of four temperatures (20, 25, 30, 35¢J) and six salinities (5, 10, 15, 20 ,25, 30psu ) were employed to study the effects of environmental factors on the speed of ciliary movement of the gill and the oxygen consumption of hard clam Meretrix lusoria and purple clam Sanguinolaria rostrata. The results show that, at the same salinities, the speed of ciliary movement of the gill and the oxygen consumption of M. lusoria increased with increasing temperature and reached the maximum at 30¢J, but declined at 35¢J. In contrast , the speed of ciliary movement of the gill and the oxygen consumption of S. rostrata increased with increasing temperature, and the maximum was at 35¢J. S. rostrata can adapt to higher temperature than M. lusoria does. At the same temperature, the speed of ciliary movement of the gill and the oxygen consumption of two bivalves increased with increasing salinity, reaching its maximum at 15~25psu, and declining at higher salinity ranges. These two bivalves like to live in estuaries. The maximal speed of ciliary movement of the gill and the maximal oxygen consumption of M. lusoria occurred at 30¢J, 20 psu (1.23 cm/min and 1.78 mgO2/hr/g, respectively). The ratio of the maximun to the minimun were 2.5 and 2.8, respectively. The maximal speed of ciliary movement of the gill and the maximal oxygen consumption of S. rostrata were at 35¢J, 25 psu (1.64 cm/min and 1.45 mgO2/hr/g, respectively). The ratio of the maximun to the minimun were 4.0 and 5.8, respectively. Temperature and salinity had more remarkable effects on S. rostrata than on M. lusoria. In another experiment, the combinations of four temperatures (20 ,25 ,30 ,35¢J) and three salinities (10, 20, 30 psu) were employed to study the effects on the speed of ciliary movement of the gill and the oxygen consumption of small M. lusoria and small S. rostrata. The results show that the effects of all temperature-salinity combination on the speed of ciliary movement of the gill and the oxygen consumption of the small bivalves were similar to that of the large ones. The physiological conditions of the small bivalves were similar to that of the large ones. The maximal speed of ciliary movement of the gill and the maximal oxygen consumption of small M. lusoria were at 30¢J, 20 psu (1.31 cm/min and 5.56 mgO2/hr/g, respectively). The ratio of the maximun to the minimun were 2.5 and 3.0, respectively. The maximal speed of ciliary movement of the gill and the maximal oxygen consumption of small S. rostrata were at 35¢J, 20 psu (1.67 cm/min and 3.96 mgO2/hr/g, respectively). The ratio of the maximun to the minimun were 2.9 and 7.1, respectively. Temperature and salinity had more remarkable effects on small S. rostrata than small M. lusoria. Our results also show that the oxygen consumption is positively correlated with the speed of ciliary movement of the gill in both bivalves (R2¡á0.94). The speed of ciliary movement of the gill can be regarded as an physiological indicator. The speed of ciliary movement of the gill of M. lusoria changed very significantly when the temperature was suddenly changed 5¢J or when the salinity was suddenly changed 10psu. The condition then stabilized only gradually. The speed of ciliary movement of the gill showed no pronounced variations after 50~70 minutes. We found that when the temperature or salinity was changed suddenly, the physiological condition of M. lusoria was disturbed and became stable after 70 minutes. M. lusoria died at 5psu (35¢J), but S. rostrata didn¡¦t. S. rostrata can adapt to higher temperature and lower salinity. The cultivation of S. rostrata is easier than M. lusoria. The effects of temperature changes were more significant than those of salinity. Temperature variations were more important than salinity variations on cultivation of M. lusoria and S. rostrata.