不同藻类对三角帆蚌能量代谢相关指标的影响

Effects of different microalgae species on bioenergetic parameters of Hyriopsis cumingii

在水温21℃时,测定暴露于相同密度8种不同藻类条件下,一龄三角帆蚌对藻类的同化率、排氨率和耗氧率,实验周期为24 h。结果显示,在相同密度下,三角帆蚌对硅藻的同化率最高,为0.660±0.003;明显高于绿藻和蓝藻(0.142±0.003和0.095±0.004);摄食蓝藻的三角帆蚌排氨率和耗氧率最大,分别为(1.346±0.024)μg/(g·h)和(25.78±0.237)μg/(g·h)。摄食绿藻的排氨率最小,为(0.795±0.015)μg/(g·h),摄食硅藻的耗氧率最小,为(13.307±0.127)μg/(g·h)。耗氧率与排氨率比值(O∶N)揭示三角帆蚌摄食硅藻后,其呼吸代谢底物主要以蛋白质为主;当饵料改变为蓝藻和绿藻时,O∶N比值开始明显变高,表明其呼吸代谢底物由以蛋白质为主转变为以脂肪和蛋白质为主。蓝藻和绿藻类浮游植物对三角帆蚌具有一定的胁迫效应。

Assimilation efficiency （AE） of triangle sail mussel Hyriopsis cumingii which fed on eight species of microalgae was determined during the 24 hours trial, at 21 ℃ of water temperature. Oxygen consumption and ammonia N excretion rates of Hyriopsis cumingii were also studied in laboratory. Results showed that AE of Hyriopsis cumingii on Bacillariophyta （0.660±0.003） was higher than that on other microalgae species at the same level of algal density. The highest oxygen rates of consumption and the highest ammonia N excretion rates were found with the group fed on the Cyanophyta, which were at 1.346±0.024 μg/（g·h） and 25.78±0.237 μg/（g·h）, respectively. while the lowest ammonia N excretion rate and the lowest oxygen rate were in Chlorophyta group （0.795±0.015 μg/（g·h）） and the Bacillariophyta group （13.307±0.127 μg/（g·h）） .Furthermore, the O∶N ratio revealed that protein was consumed by Hyriopsis cumingii when they fed on Bacillariophyta, while more fat and protein were consumed when fed on Cyanophyta or Chlorophyta.