关键词：
三角帆蚌;耗氧率;静水法;流水-静水法;流水法
摘 要：
比较采用静水法、流水法或流水-静水法(在流水条件下适应一段时间后在静水条件下测定耗氧率)对二龄三角帆蚌[蚌质量(41.95±6.23)g]耗氧率测定结果的影响.结果发现:在实验结束时采用静水法或流水-静水法的呼吸瓶内下层溶解氧(dissolved oxygen,DO)质量浓度显著低于上层和中层的DO质量浓度,而采用流水法的呼吸瓶内DO分层现象不明显;采用静水法或流水-静水法时根据实验结束时呼吸瓶内上层或中层DO质量浓度计算的耗氧率均显著低于根据下层DO质量浓度计算的耗氧率;在22℃水温下,采用流水法测定的蚌耗氧率为(504.7±103.1)mg/(kg.h),采用静水法、流水-静水法时根据各层DO质量浓度并利用修正公式计算得到的蚌耗氧率分别为(552.8±115.1)mg/(kg.h)、(625.4±72.4)mg/(kg.h),3种方法对三角帆蚌耗氧率测定结果间的差异无统计学意义(P>0.05).表明采用静水法或流水-静水法时如不注意校正呼吸瓶内DO分层将会导致测定结果出现较大的误差,因此,建议采用流水法测定贝类耗氧率.
译 名：
Comparison of methods for measuring oxygen consumption rate of Hyriopsis cumingii
作 者：
ZHENG Xiafei,WANG Yan(College of Animal Sciences,Zhejiang University,Hangzhou 310058,China)
关键词：
Hyriopsis cumingii;oxygen consumption rate;closed respirometry;flow-closed respirometry;flowthrough respirometry
摘 要：
Oxygen consumption rate is an important physiological indicator for evaluating the environmental adaptation of bivalves.Generally,oxygen consumption rate of bivalve is measured with closed respirometry or flow-through respirometry.So far,the influence of different respirometry on oxygen consumption rate of bivalve has not been well evaluated.In this paper,we reported the oxygen consumption rate of two-year-old freshwater mussel Hyriopsis cumingii(mussel mass(41.95±6.23)g)measured with closed respirometry,flow-through respirometry and flow-closed respirometry(oxygen consumption rate was measured with closed respirometry after the mussel was acclimated in flow-through respirometer for 2h),respectively.The measurement of oxygen consumption rate lasted for 2h,during which water temperature was 22℃.After the measurement,water samples were collected at the upper,middle and lower stratifications of the respiration chamber by siphon,and DO(dissolved oxygen) concentrations and pH values were measured.In the respiration chambers of the closed respirometry and flow-closed respirometry,significant stratification in DO concentration was detected.The results showed that the DO concentration was significantly higher at the upper or middle stratification than that at the lower stratification in the respiration chambers of the closed or flow-closed respirometry,whereas no significant DO stratification was detected in the respiration chambers of the flow-through respirometry.The oxygen consumption rates of the mussel based on DO concentrations at the upper and middle stratifications using closed respirometry were(100.9± 49.5) and(199.7±49.9) mg /(kg.h) respectively,which were significantly lower than the oxygen consumption rate [(1 710.8±509.6) mg /(kg.h)] calculated based on DO concentration at the lower stratification.The oxygen consumption rates of the mussel based on DO concentrations at the upper and middle stratifications using flow-closed respirometry were(390.06±88.2) and(653.3±78.7) mg /(kg.h) respectively,which were significantly lower than the oxygen consumption rate [(1 116.4±300.9) mg /(kg.h)] calculated based on DO concentration at the lower stratification.The errors introduced by the DO stratification were calibrated by measuring DO concentrations at different stratifications in the respiration chambers and calculating the oxygen consumption rate with a calibrated equation.The result indicated that the calibrated oxygen consumption rates measured with the closed and flow-closed respirometry were(552.8±115.1) and(625.4±72.4) mg /(kg.h) respectively,which did not statistically differ from the oxygen consumption rate measured with the flow-through respirometry [(504.7±103.1) mg /(kg.h)].The above results reveal that the oxygen consumption rate of the mussel can be erroneously estimated using closed or flow-closed respirometry without the calibration of DO stratification in the respiration chambers.Using the flow-through respirometry can diminish the stress of operation disturbance and monitor the oxygen consumption rate of the tested mussel at a long time scale.Therefore,the flow-through respirometry was recommended for measuring the oxygen consumption rate of bivalve.
