In this study,the authors investigated the effects of residual chlorine on mortality,grazing and respiration of Labidocera euchaeta in laboratory.The grazing rate was evaluated by subtraction method of food concentrat...In this study,the authors investigated the effects of residual chlorine on mortality,grazing and respiration of Labidocera euchaeta in laboratory.The grazing rate was evaluated by subtraction method of food concentration and respiration rate was measured using oxygen electrode.It was found that the lethal effect of residual chlorine on L.euchaeta increased with enhanced concentration and prolonged duration.The medium lethal concentration （LC 50 ） of chlorine for L.euchaeta in 24 h was about 0.58 mg/L and the safe concentration was about 0.21 mg/L.However,the grazing and respiration of L.euchaeta decreased by 32.6% and 18.9% when exposed to 0.2 mg/L residual chlorine for 4 h.It indicated that the physiological activities of zooplankton could be suppressed by the residual chlorine less than the safety concentration.Therefore,both survival and physiological activities of the organisms living in the thermal （nuclear） power plant discharging waters should be considered when carrying out the ecological risks assessment.展开更多
-The development rate of Labidocera euchaeta Giesbrecht in the Xiamen Harbor was studied in laboratory. The results showed that the development times of egg and larval stages ( D ) were significantly correlated with t...-The development rate of Labidocera euchaeta Giesbrecht in the Xiamen Harbor was studied in laboratory. The results showed that the development times of egg and larval stages ( D ) were significantly correlated with temperature ( T ), following the Belehradek function, D = α( T -7. 5)-1.0634. The development time from egg to larval stages and adult, as well as generation time can be predicted from the equation for egg development ( α=411/24) by appropriately multipling the constant (α) with a proportion. The development was not isochronal over the whole larval period. Durations of naupliar stages were short and quasi-isochronal, which favored their non-feeding development. In contrast, durations of copepodid stages (C) were long. CV had the longest duration followed by CI, both of which are considered as the critical stages in the larval development. The acclimation effect of the seasonal temperature on the development rate was also observed.展开更多
基金The National Maritime Bureau's special fund for scientific research on public causes under contract No. 200905010-12special research fund for the national non-profit institutes under contract No. 2008M15
文摘In this study,the authors investigated the effects of residual chlorine on mortality,grazing and respiration of Labidocera euchaeta in laboratory.The grazing rate was evaluated by subtraction method of food concentration and respiration rate was measured using oxygen electrode.It was found that the lethal effect of residual chlorine on L.euchaeta increased with enhanced concentration and prolonged duration.The medium lethal concentration （LC 50 ） of chlorine for L.euchaeta in 24 h was about 0.58 mg/L and the safe concentration was about 0.21 mg/L.However,the grazing and respiration of L.euchaeta decreased by 32.6% and 18.9% when exposed to 0.2 mg/L residual chlorine for 4 h.It indicated that the physiological activities of zooplankton could be suppressed by the residual chlorine less than the safety concentration.Therefore,both survival and physiological activities of the organisms living in the thermal （nuclear） power plant discharging waters should be considered when carrying out the ecological risks assessment.
文摘-The development rate of Labidocera euchaeta Giesbrecht in the Xiamen Harbor was studied in laboratory. The results showed that the development times of egg and larval stages ( D ) were significantly correlated with temperature ( T ), following the Belehradek function, D = α( T -7. 5)-1.0634. The development time from egg to larval stages and adult, as well as generation time can be predicted from the equation for egg development ( α=411/24) by appropriately multipling the constant (α) with a proportion. The development was not isochronal over the whole larval period. Durations of naupliar stages were short and quasi-isochronal, which favored their non-feeding development. In contrast, durations of copepodid stages (C) were long. CV had the longest duration followed by CI, both of which are considered as the critical stages in the larval development. The acclimation effect of the seasonal temperature on the development rate was also observed.
文摘基于2016年5月乐清湾海域的海洋调查资料,分析了浮游动物真刺唇角水蚤( Labidocera euchaeta )的优势度及其与海水盐度( S )的相关性,并利用高斯模型研究了在盐度梯度下真刺唇角水蚤丰度的生态阈值(Ecological Threshold, ET)。结果表明:真刺唇角水蚤是乐清湾海域春季浮游动物优势种之一,优势度为0.061;其丰度与盐度呈极显著负相关关系( p <0.01),盐度是影响真刺唇角水蚤水平分布的主要因素之一;其最适盐度值为21.36,最适盐度生态阈值区间为[20.17,22.55],真刺唇角水蚤在盐度梯度下的生态阈值区间为[18.99,23.73]。此外,还探讨了盐度对真刺唇角水蚤生长的影响,以及此生态阈值研究在乐清湾海域资源环境承载能力监测预警中的作用。
