壬基酚对中国林蛙蝌蚪生长发育的毒性效应

Toxicity effects of nonylphenol on tadpoles Rana chensinensis growth and development

为评价壬基酚对中国林蛙（Ranachensinensis）蝌蚪的急性毒性，将26—28期的中国林蛙蝌蚪暴露于浓度为0．05—0．5mg·L-1壬基酚（NP）的水体中进行急性毒性试验。结果表明：24、48、72、96h蝌蚪的死亡几率与浓度对数的回归方程分别为Y=8．4087x＋10．202、Y=9．5104x＋11．745、Y=10．284x＋12．498、Y=10．619x＋13．095；半数致死浓度（LC轴）分别为0．24、0．20、0．19、0．17mg·L-1；安全浓度（SC）为0．017mg·L-1；96h的LC。为0．14mg·L-1。证明林蛙蝌蚪的死亡几率与一定范围的NP浓度呈线性正相关。为探讨低浓度壬基酚对中国林蛙蝌蚪生长发育的影响，将26期林蛙蝌蚪分别在100、60、30、10μg·L-1NP的水体中连续暴露直至完全变态，并以3、0．3μg·L-1雌二醇（E：）作为阳性对照，分别统计林蛙蝌蚪暴露于NP和E：中20、40d和完成变态后幼蛙的体质量、全长以及从26期到完全变态所需的时间。结果表明，NP浓度在100μg·L-1以下，对林蛙蝌蚪不能致死。100、10μg·L-1NP与3μg·L-1 E的效应相似，均可滞后蝌蚪变态时间，降低蝌蚪变态后幼蛙的体质量。说明NP浓度在100μg·L-1以下不直接损伤蝌蚪机体，但可以通过干扰内分泌活动影响林蛙幼体的生长发育。

The individuals of tadpoles Rana chensinesis at stages 26-28 were exposed to 0.05- 0. 5 mg nonylphenol （NP） per liter water to estimate the acute toxicity effects of NP. The results showed that the regression equations between the individuals＇ death probability and the logarithm of NP concentration for 24, 48, 72 and 96 h were y = 8.4087x ＋ 10.202, y = 9. 5104x ＋ 11. 745, y = 10. 284x ＋ 12. 498, y = 10. 619x ＋ 13.095, with the mean LC50 values being 0. 24, 0.20, 0. 19 and 0. 17 mg·L-1 respectively. The safe concentration （SC） was O. 017 mg·L-1 , and the 96 h LC0 value was 0. 14 mg·L-1, suggesting that the death probability of tadpoles R. chensinensis individuals had a positive linear correlation with definite range of NP concentrations. In order to examine the effects of lower concentration NP on the growth and development of R. chensinensis, the individuals at stage 26 were continuously exposed to 100, 60, 30, and 10μg·L-1 of NP till metamorphosis, with 3 and 0.3μg·L-1 of E2 as positive control. The body mass, total length, and the duration of metamorphosis were determined at 20 days, 40 days, and after metamorphosis. It was shown that 〈 100 μg·L-1 of NP had no effects on the mortality of tad- poles R. chensinensis, while 10 and 100μg·L-1 of NP had the similar effects of 3 μg·L-1 E2, i. e. , delayed the time of metamorphosis, and decreased the body mass of froglets after metamorphosis. It was suggested that NP with the concentration of 〈 100μg·L-1 did not directly damage the organism, but disrupted its endocrine activity to affect the development of tadpoles R. chensinensis.