运用热带爪蟾胚胎检测黑臭河道底泥的生态毒性

2010年9月~12月，在温州山下河（S）和九山外河（J）先后采集底泥样品5次.将热带爪蟾胚胎（NF10—NF11）暴露于1〖DK〗∶4底泥提取液（第1—4次）和间隙水（第5次）中48 h，观测其发育状况.结果表明，山下河S1样点连续5次的底泥样品均导致胚胎全部死亡，表现出很强的毒性.暴露于山下河底泥提取液的胚胎体长均显著短于空白对照组，而暴露于九山外河底泥提取液的胚胎体长仅第3次显著短于空白对照组.暴露于山下河底泥提取液的胚胎畸形率均高于暴露于九山外河底泥提取液的，尤其在第4次检测中，暴露于S2-S4底泥提取液的胚胎畸形率均高达100%，而九山外河最高仅为70%（J2）和40%（J1）.热带爪蟾胚胎直接暴露于所有采样点的山下河底泥间隙水均全部死亡.由此可见，山下河的整体毒性高于九山外河，底泥间隙水毒性高于底泥提取液.本研究表明，温州市典型的黑臭河道底泥对爪蟾胚胎的发育均有不同程度的影响，具有明显的生态毒性.同时，运用爪蟾胚胎可以有效地检测底泥的毒性效应，而且对不同河流和采样点的毒性评价具有较好的区分度.

Screening the ecological toxicity of sediments in black-odors rivers using Xenopus tropicalis embryos

To assess the pollution and management effects of the black-odors rivers from Wenzhou,we screened the toxocity of aqueous sediment extracts and interstitial water of rivers using Xenopus tropicalis embryos.The surface sediment samples were collected for 5 times from September to December in 2010.The embryos were exposed to the extracting solution of the sediments (1:4) for the first to the fourth tests and in the interstitial water for the fifth test for 48 h.Our results showed that all the embryos treated with samples from S1 died after 48 h of exposure during the 5 tests.This suggested that the sediments in S1 showed very high toxicity.Compared with the control,the body length of embryos treated with aqueous sediments extracts from Shanxia River was significantly decreased,but the body length of embryos treated with those from Jiushan River was decreased only in the third test.The percent of malformations were higher in Shanxia River than that in Jiushan River.Especially,the percent of malf oration was up to 100%in S2-S4,but the highest of percent of malformations was only 70%(J2) and 40(J1) in Jiushan River.The interstitial water of sediments in Shanxia River led to the death of all embryos. These results suggested that the toxicity of sediments in Shanxia River was generally higher than that in Jiushan River,and that the interstitial water was more toxic than aqueous sediments extracts.Our study indicates that the sediments of the black-odors rivers have adverse effects on the development of X.tropicalis embryos and show significant ecological toxicity.In addition, X.tropicalis embryos can be used for screening the hazards of sediments effectively.