铬对中国林蛙蝌蚪生长发育的毒性效应  

Toxicity effect of chromium on the growth and development of Rana chensinensis tadpoles

作　　者：李勃[1,2] 王维君[1] 李忻怡[1] 张育辉[1] 

机构地区：[1]陕西师范大学生命科学学院,西安710062 [2]陕西省微生物研究所,西安710043

出　　处：《生态学杂志》2013年第3期648-654,共7页Chinese Journal of Ecology

基　　金：国家自然科学基金资助项目(30770243);陕西省科学院重点项目(2010ZD01);中央高校基本科研项目(GK200902039)资助

摘　　要：为评价水域环境中铬元素对两栖动物幼体的急性毒性,将中国林蛙(Rana chens-inensis)28～29期蝌蚪分别暴露于30～35mg·L-1Cr(Ⅲ)6个不同浓度和10～45mg·L-1Cr(Ⅵ)6个不同浓度的水体中,分别在24、48、72和96h统计蝌蚪的死亡率及半致死浓度(LC50)。结果表明:暴露24、48、72和96h,Cr(Ⅲ)对蝌蚪的LC50分别为34.09±1.06、33.47±0.65、32.58±0.11和(32.05±0.20)mg·L-1,安全浓度(SC)为(3.21±0.02)mg·L-1;Cr(Ⅵ)对蝌蚪的LC50分别为91.97±5.32、51.19±4.62、35.79±1.40和(28.81±1.87)mg·L-1,安全浓度(SC)为(2.88±0.19)mg·L-1。观察表明:Cr(Ⅲ)的急性毒性是通过与蝌蚪皮肤表面的分泌物结合后粘附在鳃部,导致呼吸障碍致死;而Cr(Ⅵ)的强氧化性可导致蝌蚪的表皮溃变,鳃部萎缩致死;另外,将28～29期蝌蚪暴露于安全浓度(SC)以下的含铬水体进行慢性实验,通过检测蝌蚪的体长、体重和完全变态时间显示,低浓度的Cr(Ⅲ)和Cr(Ⅵ)对蝌蚪的生长发育仍具有一定的抑制作用,并可导致畸型发生,其作用强度呈现剂量效应,但时间累积效应不规律。In order to evaluate the acute toxicity of chromium （Cr） on amphibian larvae, the Rana chensiensis tadpoles at the stages 28-29 were exposed to the water contaminated by 30-35 mg·L^-1 of Cr（III） and 10-45 nag ·L^-1 of Cr（ VI）, with the death rate of the tadpoles and the sublethal concentration （LCso） of Cr （III） and Cr （VI） for 24, 48, 72, and 96 h determined, respectively. Both the Cr（III） and the Cr（VI） had obviously acute toxicity on the tadpoles. The LCs0 of Cr（III） for 24, 48, 72, and 96 h was 34.09 ± 1.06, 33.47 ±0.65, 32.58 ±0.11, and 32.05±0.20 mg ·L^-1 , and the LCs0 of Cr（VI） was 91.97±5.32, 51.19±4.62, 35.79±1.40, and 28.81~1.87 mg·L^-1 , respectively. The safe concentration （SC） of Cr（III） and Cr（VI） was 3.21±0.02 and 2.88±0.19 mg·L^-1, respectively. The acute toxicity of Cr（III） was from its combination with the skin secretion of the tadpoles, forming a complex compound sticking on the gill chamber, and then, causing the tadpoles dead from breath obstacle; whereas the acute toxicity of the Cr（VI） was due to its strong oxidizing property, causing the tadpoles skin fester, gill atrophy, and ultimately, the mortality of the tadpoles. The assessment of the sublethal con- centrations of Cr（III） and Cr（VI） on the growth and development of R. chensiensis tadpoles showed that Cr was a teratogenic substance which could restrain the growth and development of the tadpoles. This effect also had a dose-effect relationship with the Cr concentrations, but the time cumulative effect was irregular.

关 键 词：铬 中国林蛙蝌蚪 毒性 生长发育 

分 类 号：X174[环境科学与工程—环境科学]