Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region, Ministry of Education, Chang'an University, Xi'an, 710064, China; School of Environmental Science and Engineering, Chang'an University, Xi'an, 710064, China.
Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region, Ministry of Education, Chang'an University, Xi'an, 710064, China; School of Environmental Science and Engineering, Chang'an University, Xi'an, 710064, China.
Chemosphere. 2017 Sep;182:617-623. doi: 10.1016/j.chemosphere.2017.02.156. Epub 2017 Apr 3.
Although nitrogen fertilizer is commonly used worldwide, little information is currently available about NH-N toxicity on amphibians. This study determined the acute and chronic toxic effects of NH-N on two native Chinese amphibian species (Bufo gargarizans and Rana chensinensis), and compared the negative sensitivity of different embryos to NH-N. Static renewal aqueous exposures were performed using B. gargarizans and R. chensinensis embryos at Gosner stage 2 over 96 h. In terms of 96 h-LC, B. gargarizans and R. chensinensis embryos had significantly different responses to NH-N, and the latter was more sensitive to NH-N than the former. In the chronic toxicity test, exposure to 10 mg LNH-N or higher significantly decreased the hatching rate of embryos in both species. Significant increases in the abnormality rate of embryos at 50 mg LNH-N or higher were observed and morphological abnormalities were characterized by axial flexures, yolk sac edema, and hyperplasia in both species. Additionally, the total length of embryos decreased in a dose-dependent manner after exposure to NH-N. The results indicate that NH-N exposure can increase abnormality and inhibit the hatching and development of embryos in B. gargarizans and R. chensinensis.
尽管全球范围内普遍使用氮肥，但目前有关氨氮对两栖动物的毒性的信息却很少。本研究确定了 NH-N 对两种中国本土两栖动物（中华蟾蜍和中国林蛙）的急性和慢性毒性作用，并比较了不同胚胎对 NH-N 的负敏感性。使用 B. gargarizans 和 R. chensinensis 胚胎在 Gosner 阶段 2 下进行了 96 小时的静态更新水暴露实验。就 96 小时 LC 而言，B. gargarizans 和 R. chensinensis 胚胎对 NH-N 的反应有明显差异，后者对 NH-N 的敏感性高于前者。在慢性毒性试验中，暴露于 10mg/L NH-N 或更高浓度会显著降低两种物种胚胎的孵化率。在 50mg/L NH-N 或更高浓度下，胚胎的畸形率显著增加，两种物种的形态畸形特征为轴向弯曲、卵黄囊水肿和增生。此外，暴露于 NH-N 后，胚胎的总长度呈剂量依赖性下降。结果表明，NH-N 暴露会增加畸形率，并抑制中华蟾蜍和中国林蛙胚胎的孵化和发育。
