水体中铅暴露对南方鲇 Silurus meridionalis胚胎发育和仔鱼存活的影响  

On Effect of Lead on Embryonic Development and Larval Survival of Southern Catfish(Silurus meridionalis)

作　　者：罗其勇[1] 闫玉莲[1] 李健[1] 房树林 潘天扬 谢小军[1] 

机构地区：[1]西南大学生命科学院,水生生物及水环境研究所,重庆400715

出　　处：《西南师范大学学报（自然科学版）》2015年第5期67-74,共8页Journal of Southwest China Normal University(Natural Science Edition)

基　　金：国家自然科学基金资助项目(31300338);重庆市自然科学基金重点项目(CSTC2013jjB80008);重庆市科委自然科学基金计划资助项目(CSTC2012jjA20017)

摘　　要：采用人工受精获得的南方鲇Silurus meridionalis Chen胚胎和仔鱼为实验对象,以Pb(NO3)2为毒物源,在水温22.5℃条件下,观察了水体中不同质量浓度铅(Pb)暴露对南方鲇胚胎孵化率、畸形率、自主运动、孵化历时的影响,并进行了初孵仔鱼的Pb暴露毒理实验.实验结果表明,在水体中Pb2+质量浓度分别为0(对照),4,8,12和16mg/L的条件下,南方鲇胚胎孵化率随着Pb质量浓度的上升呈下降趋势,分别为84.94%,71.23%,69.75%,66.57%和64.69%,各Pb质量浓度处理组的孵化率显著低于对照组(p<0.05);且孵出的仔鱼出现心包水肿,脊柱弯曲以及尾巴弯曲退化等畸形特征,畸形率随着Pb质量浓度的升高呈上升趋势,分别为10.27%,15.28%,22.28%和36.67%,各Pb暴露组均显著高于对照组(2.37%)(p<0.05);各Pb质量浓度暴露组胚胎在出膜前期的自主运动频率分别为63.86,52.71,48.43和47.14次/min均显著低于对照组(78.00次/min)(p<0.05);各Pb质量浓度暴露组的胚胎孵化历时均显著长于对照组(p<0.05).孵化后在净水(未加入Pb(NO3)2的实验水体)中养殖的卵黄囊期仔鱼72h死亡率随着其胚胎期Pb暴露质量浓度的上升呈上升趋势,胚胎期Pb暴露质量浓度分别为0,4,8,12和16mg/L的条件下,仔鱼期的净水死亡率分别为9.45%,18.22%,20.95%,24.05%和26.29%,胚胎期各Pb质量浓度暴露组所获仔鱼的死亡率均显著高于对照组(p<0.05).根据水体Pb暴露对南方鲇初孵仔鱼急性中毒致死的观测结果推算,其96h半致死质量浓度(96hLC50)为0.32mg/L.本研究结果表明,南方鲇胚胎对水体Pb暴露的耐受性高于其初孵仔鱼,可能与南方鲇的受精卵卵膜较厚,对水体中的Pb2+进入胚胎具有较大的阻滞作用有关.To determine the toxic effects of waterborne Lead （Pb） on embryonic and larval development of the southern catfish （Silurus meridionalis Chen） ,the embryos and larvae which have been bred with arti-ficial fertilization have been exposed to Pb solutions of five nominal concentrations （0 ,4 ,8 ,12 and 16 mg/L） at 22 .5℃ respectively .Embryonic hatching rate ,larval malformation rate ,spontaneous movements , incubation period have been evaluated at the end of embryonic period . Acute toxicity of Pb to newly hatched larvae has also been determined in this study .Embryonic hatchability has decreased with the in-creasing Pb concentration .The value in the groups of 4 ,8 ,12 and 16 mg/L were 71 .23% ,69 .75% ,66 .57%and 64 .69% respectively ,which are significantly lower compared with the control group （84 .94% ） （p〈0 .05） .Furthermore ,exposure of embryos to Pb has significantly increased morbidity of body malforma-tions in newly hatched larvae ,such as pericardial edema ,body curvature and degenerated tail .In the groups of 4 ,8 ,12 and 16 mg/L ,the malformation rate of newly larvae are 10 .27% ,15 .28% ,22 .28%and 36 .67% respectively ,which are significantly lower than that of the control group （2 .37% ） （p〈0 .05） .The average spontaneous movements of embryos decreased along the contamination gradient .In the concentrations of 4 ,8 ,12 and 16 mg/L ,the value are 63 .86 ,52 .71 ,48 .43 and 47 .14 beats/min , which are significantly lower compared with the control group （78 .00 beats/min） before hatching （44 hours post-fertilization） （p〈0 .05） .Pb also has an inhibitory effect on hatching time .The incubation peri-ods are significantly delayed compared to control （p〈0 .05） .Exposures to waterborne Pb during embryon-ic period alone causes adverse impact on larval performance even w hen larval development took place in clean w ater .And the lowest larval mortality in 72 hours after hatching occurred in the control group （9 .45% ） , which is significantly lower th

关 键 词：铅(Pb) 胚胎 仔鱼 急性毒性 南方鲇 LEAD (Pb) 

分 类 号：Q959.4[生物学—动物学]