The Toxicity Studies Of Chlorine Dioxide And Malachite Green On Crucian (Carassius Auratus)

This paper utilized Cruciam(Carassius auratus) as the experimental fish and studied the acute toxicity tests of chlorine dioxide and malachite green on Crucian; The activity change trend of catalase(CAT),superoxide dismutase(SOD) and glutathione-S-transferase(GST) in the liver and muscle were studied in exposure to different concentrations of chlorine dioxide and malachite green.The effect of chlorine dioxide and malachite green on Crucian serum biochemical indicators (glucose GLU,total cholesterol T-CHO,albumin ALB and total protein TP) were studied too.The main research results were as follows:1.The acute toxicity test of chlorine dioxide and malachite green on larvae Crucian were studied by hydrostatic biological test.The semi-lethal concentration (LC₅₀) on 24h,48h,96h and the safe concentration of the two drugs to Crucian were determined.The results indicated that,the semi-lethal concentration on 24,48h and 96h of chlorine dioxide to Crucian were 23.34,20.80 and 20.40mg/L,safe concentration was 2.04mg/L;the semi-lethal concentration on 24h,48h and 96h of malachite green to Crucian were 0.44,0.35 and 0.31mg/L,safe concentration was 0.031mg/L.According to the toxicity evaluation criteria of toxic substances to fish, chlorine dioxide is the low toxicity to Crucian,but malachite green is the high toxicity.2.Crucian were dealed with four chlorine dioxide concentration of 4.08,2.04,1.02 and 0.51mg/L.The activities of antioxidant enzymes and serum biochemical indicators were mensurated in 0d,2d,4d,8d,16d,24d by reagent box. The results were as follows:The activity of SOD in liver of Crucians was inhibited first,then activated,but was lower than the control group at all times;Chlorine dioxide had no significant effect to the activity of CAT in liver;The activity of GST in liver was activated in the initial experiment then suppressed;The activity of SOD in muscle remained almost unchanged in the low concentration group,while it was first rise then fall and eventually stabilized in the high concentration group;The activity of GST in muscle was varied by the concentration of chlorine dioxide,the higher the concentration,the greater inhibited degree of GST:The activity of these three enzymes in liver were higher than in muscle.The content of glucose had no significant change in low concentration group,and it was increased after the first drop in high concentration group.GLU content of the highest concentration was signiticantly lower than the control group(P＜0.01) at 8d:Content of T-CHO was depressed then rising to the normal level gradually,there was no significant difference(P＞0.05)in different groups;chlorine dioxide had almost no effect on content of serum ALB;Chlorine dioxide had promoted the TP content mainly,the trend of TP content was increased then drop,the two higher group were very significantly higher(P＜0.01)than the control group in the first 8d,at the end of the experiment,TP content slight decreased,but TP content of all the group's were still equal to or higher than the control group.3.The change trend of activities of antioxidant enzymes and serum biochemical indicators were studied in different concentration of malachite green(62.00,31.00, 15.50 and 7.75μg/L)at 0d,2d,4d,8d,16d,24d.The results indicated that,the activity of SOD in liver was inhibited-promoted- inhibited,and the higher the concentration of MG,the greater inhibited or activation degree of SOD activity;the activity of CAT in liver was inhibited then activated,finally stabilized gradually,the time of induced.was short,the high concentration of group the changes of CAT activity in hinger concentration were significanter than the lower;The activity of GST in liver had a short-term suppression only at the beginning of the experiment, and then activated gradually;The activity of SOD and GST in muscle were reduced then stabled gradually,suppression of enzyme activity had positive correlation with concentration of MG;GLU of Crucian was sensitive to MG,GLU concentration was decreased in the beginning,with the exposure time,GLU concentration has been declining in high concentrations group,the change of the other group were not significant,at the end of the experiment,GLU content of the lowest concentration group had no significant difference(P＞0.05) with the control group,the other three groups were very significant difference(P＜0.01) with the control group;T-CHO was also sensitive to MG,in the early exposure,T-CHO content changed little,with the exposure time,the concentration of T-CHO declined verily in different group;With the increasing concentration of malachite green and exposure time.ALB contene of Crucian declined;MG had promoted the TP content mainly,TP content of all the group's were all significantly(P＜0.05)or very significantly(P＜0.01) higher than the control group at the end of the experiment.The results indicated that changes of indicators in the Crucian exposed in MG were more significant than in chlorine dioxide,it indicated that MG was more venenous to Crucian.