Effects of Temperature and Salinity on Oxygen Consumption and Ammonia Excretion Rate of Whelk Cantharus cecillei with Different Sizes

Abstract:

In this study we used static water method to investigate the effects of temperature and salinity on oxygen consumption rate and ammonia excretion rate of Cantharus cecillei with two different sizes. The results were described as following: (1) Temperature and body size alone had significant effects on oxygen consumption rate (OR) and ammonia excretion rate (NR) (P<0.05), but the interaction of the two factors did not affect OR or NR (P>0.05). OR and NR increased along with rise in temperature (12−24℃) and reached the peak value at 24℃, but then started to decrease as the temperature continued to increase. At 12−28℃ OR and NR of the large size group (A group) were both lower than those of the small size group (B group). At 12−28℃, the O and N mole ratio varied between 8.17 and 17.31 and reached the highest at 20 and 24℃, and the ratio dropped at 28℃. (2) Salinity and body size alone also had significant effects on OR and NR (P<0.05) whereas the combination did not (P>0.05). At salinity 20−30, OR and NR increased along with salinity, and the peak value appeared at salinity 30, followed by a decrease as the salinity continued to rise. At salinity 20−40, OR and NR of A group were both lower than those of B group. The O and N mole ratio varied between 10.80 and 22.71, and the highest value appeared at salinity 30 before it began to fall along with further increase in the salinity. This study indicated that the optimum temperature and salinity for C. cecillei could be 24℃ and 30 respectively, and provided basic data for the development of the farming of C. cecillei.