Effects of temperature on the oxygen consumption rate, ammonia excretion rate and their diurnal variations of Potamilus alatus

Abstract:

The oxygen consumption rate (OCR) and ammonia excretion rate (AER) of pink heel splitter Potamilus alatus were studied using closed respirometry under three different water temperature conditions. The respiratory metabolic differences between male and female mussels and the diurnal variation were studied.. The results show that when water temperature ranges from 17 ℃ to 27 ℃, both OCR and AER increase with the increase of water temperature; the OCR of male mussels is higher than that of females but the difference is not significant, whereas the AER of males is lower than that of females and the difference is significant at 22 ℃ and 27 ℃(P=0.014,P<0.01). At 27 ℃, the oxygen nitrogen ratio of male mussels is significantly higher than that of females(P=0.019, P<0.05), possibly due to their physiological differences. When temperature is at 22 ℃,there are obvious diurnal variations in both OCR and AER which are significantly higher in nighttime than daytime; the respiratory metabolism peak of both males and females appears in the early morning from AM 1:00 to 3:00, while all troughs are found in the afternoon from 15:00 to 17:00 except that the AER of males appears between AM 9:00-11:00;during the whole day, the males show a higher average OCR and lower AER compared with females, but the difference is not significant (P>0.05). The present study preliminarily reveals the effect of temperature on the respiratory metabolism and diurnal variation of pink heel splitters, providing theoretical references for enhancing the domestication survival rate, improving reasonable pond stocking and for further research on male-female growth differences.