3种渔用药物对斜生栅藻的毒性效应研究

Toxic Effects of Three Fishery drugs on Scenedesmus obliquus

强力霉素、甲苯咪唑和替米考星是水产养殖业中的常用渔用药物,为了阐明这3种渔用药物对水环境中斜生栅藻(Scenedesmus obliquus)的毒性效应,研究了强力霉素、甲苯咪唑和替米考星对斜生栅藻生长和叶绿素a含量的影响。结果表明,低质量浓度(2 mg·L^(-1))的强力霉素对斜生栅藻的生长和叶绿素a的含量均具有促进作用,高质量浓度(12、27和64mg·L^(-1))时则表现出明显的抑制效应,且质量浓度越高,抑制效应越强。质量浓度为5 mg·L^(-1)的强力霉素在48~72 h之间对斜生栅藻叶绿素a的含量具有促进作用,96 h后才开始表现出抑制作用。甲苯咪唑在低质量浓度(0.5 mg·L^(-1))时对斜生栅藻的生长和叶绿素a的含量便表现出抑制效应,且抑制效应随其质量浓度(1、2、3、4 mg·L^(-1))的增加而增强。替米考星在质量浓度为0.5 mg·L^(-1)时,48 h内对斜生栅藻的生长和叶绿素a的含量没有明显作用,48~96 h表现出抑制作用;而在1~8 mg·L^(-1)浓度范围则均表现出抑制作用。强力霉素、甲苯咪唑和替米考星对斜生栅藻24 h、48 h、72 h和96 h的半抑制质量浓度(EC50)分别为9.564、11.905、11.046、16.214 mg·L^(-1),1.198、3.979、5.118、3.940 mg·L^(-1),7.744、7.691、7.548、7.251 mg·L^(-1)。甲苯咪唑(0.5、1、2、3和4 mg·L^(-1))、强力霉素(2、5、12、27和64 mg·L^(-1))和替米考星(0.5、1、2、4和8 mg·L^(-1))分别处理斜生栅藻96 h后叶绿素a含量分别为空白对照组的89.8%、70.8%、26.6%、15.5%和7.5%,111.9%、94.1%、65.9%、58.5%和30.3%,81.5%、55.6%、47.4%、20.7%和13.3%。3种渔用药物对斜生栅藻的毒性效应表现为甲苯咪唑>替米考星>强力霉素。

Doxycycline,mebendazole and tilmicosin as the fishery drugs are commonly used in aquaculture.In order to reveal thetoxic effect of the three fishery drugs on Scenedesmus obliquus,the growth and content of chlorophyll a of Scenedesmus obliquuswere investigated.The results showed that the growth of Scenedesmus obliquus was promoted by doxycycline at the low massconcentration of2mg·L-1and inhibited at these high mass concentrations of12,27and64mg·L-1,and the inhibition effectsincreased with the increasing of doxycycline mass concentrations.The content of Scenedesmus obliquus chlorophyll a was promotedat the doxycycline mass concentration of5mg·L-1between48h and72h,and the inhibition effect was observed at96h.Theinhibition effect on the growth and the content of Scenedesmus obliquus chlorophyll a was observed at the mebendazole massconcentration of0.5mg·L-1and the effect increased with the increasing of mass concentrations(1,2,3and4mg·L-1).The weakeffect on the growth and the content of Chlorophyll a of Scenedesmus obliquus at the mass concentration of0.5mg·L-1within48h,and the inhibition effect was observed from48h to96h,and the inhibition effects were all presented in the range of massconcentration from1mg·L-1to8mg·L-1.The24h,48h,72h and96h-EC50of doxycycline,mebendazole and tilmicosin toScenedesmus obliquus were9.564,11.905,11.046and16.214mg·L-1,1.198,3.979,5.118,3.940mg·L-1and7.744,7.691,7.548and7.251mg·L-1,respectively.The content of Chlorophyll a of Scenedesmus obliquus treated with mebendazole(0.5,1,2,3and4mg·L-1),doxycycline(2,5,12,27and64mg·L-1)and tilmicosin(0.5,1,2,4and8mg·L-1),were89.8%,70.8%,26.6%and15.5%;7.5%,111.9%,94.1%,65.9%,58.5%and30.3%,81.5%,55.6%,47.4%,20.7%and13.3%compared with control group respectivelyat96h.The order of toxic effect on Scenedesmus obliquus of the three3fishery drugs was mebendazole>tilmicosin>doxycycline.