Cu2＋和Cd2＋对日本青鳉(Oryzias latipes)早期发育阶段的急性毒性效应研究

Acute Toxicity Effects of Copper and Cadmium on the Early Developmental Stage of Oryzias latipes

为探究并比较淡水鱼种日本青鳉早期发育阶段对Cu^(2+)和Cd^(2+)等重金属胁迫的响应,在实验室通过半静态方式,对日本青鳉受精卵和仔稚鱼分别进行了48 h和96 h急性毒性实验。结果表明:Cu^(2+)对日本青鳉胚胎24、48 h-LC_(50)分别为8.164 mg·L^(-1)和6.965 mg·L^(-1);Cd^(2+)对日本青鳉胚胎24、48 h-LC_(50)分别为63.084 mg·L^(-1)和53.093 mg·L^(-1);较低浓度组Cu^(2+)(≤1.97 mg·L^(-1))时日本青鳉胚胎的发育速率快于对照组,而较高浓度组(≥3.87 mg·L^(-1))胚胎的发育速率则慢于对照组;与Cu^(2+)略有不同,无论浓度高低Cd^(2+)对胚胎的孵化速率均产生抑制作用;Cu^(2+)和Cd^(2+)质量浓度分别高于1.97 mg·L^(-1)和19.68 mg·L^(-1)时,两种重金属离子均显著降低胚胎的孵化率(P<0.05)。Cu^(2+)对日本青鳉初孵仔鱼24、48、72和96 h-LC_(50)分别为5.361 mg·L^(-1)、2.844 mg·L^(-1)、2.020 mg·L^(-1)和1.352 mg·L^(-1);Cd^(2+)对日本青鳉初孵仔鱼24、48、72和96 h-LC_(50)分别为15.907 mg·L^(-1)、10.550 mg·L^(-1)、7.986 mg·L^(-1)和6.346 mg·L^(-1);Cu^(2+)对日本青鳉稚鱼24、48、72和96 h-LC_(50)分别为5.732 mg·L^(-1)、4.037 mg·L^(-1)、2.498 mg·L^(-1)和1.955 mg·L^(-1);Cd^(2+)对日本青鳉稚鱼的24、48、72和96 h-LC_(50)分别为16.419 mg·L^(-1)、11.745 mg·L^(-1)、8.516 mg·L^(-1)和6.776 mg·L^(-1)。与其它淡水水生生物相比,日本青鳉仔稚鱼对铜和镉离子较为敏感。

In order to explore and compare the toxicity responses of Oryzias latipes at its early developmental stage under the exposure of Cu2＋ and Cd2＋, static-renewal acute toxicity （48 h） on the embryo of Oryzias latipes and acute toxicity （96 h） on the fry and fingerling were investigated. The results showed that the 24 and 48 h-LC50values were 8.164 and 69965 mg·L（-1） ,respectively,for Cu2＋-exposed embryos of Oryzias latipes ; and were 63.084 and 53.093 mg·L（-1） ,respectively, for Cd2~ -exposed embryos of Oryzias latipes. Embryo incuba- tion time of Oryzias latipes was shortened in low Cu2＋ concentration （〈--1997 mg·L（-1）） while was prolonged in high Cu2＋ concentration （i〉3.87 mg·L（-1））. In contrast, regardless of what the cadmium concentration was, all the embryo incubation time of Oryzias latipes exposed to Cd2＋ were prolonged significantly. Cu2＋ and Cd2＋ could decrease the hatchability of the embryos when the concentrations were higher than 1.97 mg·L（-1） and 19.68 mg·L（-1） ,respectively. The 24,48,72 and 96 h-LC50 values for Oryzias latipes larvae exposed to Cu2＋ were 5.361,2.844,2.020 and 1352 mg·L（-1） ,respectively;the 24,48,72 and 96 h-LC50 values for Oryzias latipes larvae exposed to Cd2＋ were 15.907,10.550,7.986 and 6.346 mg·L（-1） , respectively ; the 24,48,72 and 96 h-LC50 values for Oryzias latipes fingerling exposed to Cu2＋ were 5.732,4.037,2.498 and 1.955 mg·L（-1） ,respectively ;and the 24,48,72 and 96 h-LC50 values for Oryzias latipes fingerling exposed to Cd2＋ were 16.419,11.745,8.516 and 6.776 mg·L（-1） ,respectively. Compared with other freshwater aquatic organisms ,the Oryzias latipes fry and fry and fingerling were sensitive to copper and cadmium.