Effects of salinity and acidity on oxygen consumption and ammonia excretion rates of Coelomactra antiquata

LUO Jie; WANG Zhongduo; CAO Fujun; LIANG Libin

doi:10.13984/j.cnki.cn37-1141.2023.06.013

Abstract：At salinities(12,17,22,27,32 and 37)and acidities(pH5.0,6.0,7.0,8.0,9.0 and 10.0),the effects of large(L),medium(M)and small(S)of C.antiquata on oxygen consumption and ammonia excretion rates were studied with experimental ecological method.The results showed that salinity has a significant effect on the oxygen consumption rate of C.antiquata(p＜0.05),and a very significant effect on ammonia excretion rate(p＜0.01).Within the salinity range set,the oxygen consumption rate of C.antiquata rised with the increase of salinity when the salinity varied between 12 and 22,and maximized at 22 and decreased with the increase of salinity.The ammonium excretion rate reached its maximum when the salinity was 27,and then decreases with the increase of salinity.Acidity had significant effects on both oxygen consumption rate and ammonia excretion rate of C.antiquata(p＜0.05).With the increase of acidity,the oxygen consumption rate and ammonia excretion rate of C.antiquata increased first and then decreased,reached the maximum at pH8,and then decreased gradu-ally.Under the same salinity or acidity,the oxygen consumption rate and ammonium excretion rate of C.antiquata of different specifications decreased with the increase of unit body mass,and unit body mass had a very significant influence on the oxygen consumption rate and the ammonia excretion rate(p＜0.01).In the salinity experiment,the O∶N ratio of the three specifications of C.antiquata ranged from 5.733 to 7.543,increasing first and decreasing then with the increase of salinity.With the increase of acidity,the variation of O∶N varied in a similar way of salinity,ranging from 5.722 to 6.574,and reached the maximum at pH 7.The O∶N increased with the increase of individual.The change of salinity or acidity had little effect on O∶N ratio.