河流汞污染对青鳉鱼早期发育的毒性影响

清镇市化工厂是贵州省东门桥河汞污染的重要来源。为了评估这条河流的汞污染程度,本研究调查了东门桥河环境样品中的汞含量和分布情况。河流水体总汞(THg)和甲基汞(MeHg)的平均含量分别为(135.79±47.40)和(0.64±0.58) ng·L^-1;生物膜中THg和MeHg的平均含量分别为(3.38±1.91) mg·kg^-1和(10.47±0.40)μg·kg^-1;沉积物中THg和MeHg的平均含量分别为(23.21±20.22) mg·kg^-1和(32.74±10.96)μg·kg^-1。为了进一步了解这条河流中汞对水生生物的风险,将青鳉鱼胚胎和仔鱼分别暴露于从河中收集的被汞污染的河水、生物膜和沉积物中。青鳉鱼胚胎经15 d暴露后,孵化时间延长、孵化率显著降低,死亡率显著升高,实验暴露还导致胚胎无法破膜、卵黄囊水肿等畸形效应,以及初孵仔鱼不同程度的畸形。青鳉鱼仔鱼经24、48、96 h和21 d暴露后,各暴露组的死亡率和畸形率随着暴露时间的延长而显著升高,且表现出一系列以脊...

Toxic effects of river mercury contamination on early development of Oryzias latipes

The Qingzhen chemical industry is an important source of Hg pollution to the Dongmenqiao River,Guizhou Province,southwest China.To evaluate the Hg pollution status of this river,we measured the concentration and distribution of Hg in environmental samples collected from the Dongmenqiao River.The average THg and MeHg concentrations were(135.79±47.40)and(0.64±0.58)ng·L-1 in river water,(3.38±1.91)mg·kg^-1 and(10.47±0.40)μg·kg^-1 in biofilms,and(23.21±20.22)mg·kg^-1 and(32.74±10.96)μg·kg^-1 in sediments,respectively.To further clarify the risk of mercury on aquatic organisms in this river,embryos and larvae of Oryzias latipes were exposed to different treatments with Hg-contaminated water,biofilms and sediments collected from the river.After 15 days of exposure,the hatching time of embryos was prolonged,the hatching rate was significantly decreased,and the mortality rate was significantly increased.The results showed the inability of embryos in breaking the membrane,yolk sac edema and other malformation effects,as well as different degrees of malformation of the newly hatched larvae.After 24 h,48 h,96 h,and 21 d exposure,the mortality and deformity rates significantly increased with the increasing time of exposure,and a series of deformity effects occurred mainly as spinal curvature.Our results indicated that mercury pollution in the Dongmenqiao River may significantly affect the early growth of O.latipes.