阿曼原油和溢油分散剂对斑马鱼(Danio rerio)胚胎形态发育的毒性效应

Morphological and Developmental Toxicity of Oman Crude Oil and Dispersant to Zebrafish(Danio rerio) Embryos

为研究经溢油分散剂(GM-2)处理阿曼原油对硬骨鱼类形态学发育毒性,将斑马鱼胚胎作为受试生物,采用半静态暴露方法,观察0~120 hpf(hour post-fertilization)斑马鱼胚胎的致死率、孵化率和畸形率,并应用斑马鱼胚胎发育毒性试验形态学得分系统(General Morphology Score(GMS)System)评估阿曼原油暴露诱导的斑马鱼胚胎形态发育毒性。结果显示,相较于水溶组分(water-accommodated fractions,WAF),加入GM-2后的化学增强型水溶组分(chemically enhanced water-accommodated fractions,CEWAF)水样中总石油烃(total petroleum hydrocarbons,TPH)浓度显著增加,由(5.233±0.213)mg·L-1增至(292.989±11.905)mg·L-1;120 hpf时,WAF和CEWAF组的致死率均有不同程度的升高,100%WAF的致死率为30.2%±2.8%,而≥40%CEWAF的致死率均已超过半数致死率,其半数致死浓度LC50为153.318 mg·L-1;通过对GMS分析,WAF和CEWAF暴露均会在不同程度上导致斑马鱼胚胎发育显著延迟,主要表现在鱼鳔未形成、心率异常、血液循环停滞和行动(胸鳍摆动、尾部摆动等)迟缓,且均能显著延迟胚胎孵化甚至造成胚胎不孵化;由畸形率可知,阿曼原油具有较强的致畸性,以心包水肿、背部弯曲和尾部弯曲最显著。由结果可知,经GM-2处理后的阿曼原油(CEWAF)比未处理的阿曼原油(WAF)对斑马鱼胚胎产生更严重的毒性效应。

To determine the morphological and developmental toxicity of Oman crude oil dispersed by GM-2 dispersant to the teleost, zebrafish （Danio rerio） embryo was chosen to be semi-statically exposed to water-accommo- dated fractions （WAF） of Oman crude oil, GM-2 dispersant and chemically enhanced water-accommodated fractions （CEWAF） of Oman crude oil （dispersed by GM-2） at 0-120 hpf （hour post-fertilization） with observing the lethality, hatching and malformation rates. And the general morphology score （GMS） system was used to assess the morphological and developmental toxicity induced by crude oil. Resuks indicated that compared to that of WAF （with a maximum concentration of 5.233 mg·L-1 ＋0.213 mg·L-1）, total petroleum hydrocarbons （TPH） concentra- tions of CEWAF apparently increased to 292.989 mg·L-1± 11.905 mg·L-1. Lethality induced by WAF and CEWAF also increased with a varying extent, which was only 30.2% ±2.8% at 100% WAF, but was more than the median lethal rate at ≥ 40% CEWAF with the LC50 of 153.318 mg·L-1. By GMS analysis, WAF and CEWAF could significantly delay the development of zebrafish embryos to some extent, especially inducing swim bladder absence, heart rate abnormality, circulation stagnation and sluggish movement （pectoral fins, tail, etc.）. Meanwhile, WAF and CEWAF also delayed embryo hatching notably, and even caused embryo unhatching. Results also revealed that O- man crude oil is highly teratogenic, especially in term of pericardial edema, deformed body shape and malformation of the tail. This study indicated that CEWAF of Oman crude oil （dispersed by GM-2） is more toxic than WAF to zebrafish embryo.