Biotoxicity Effect Studies On Dichlorvos And Cyfluthrin In Ctenopharyngodon Idellus

Fish is one of the main economical resouse.It sets up the aquatic ecological system with the aquatic organisms and the surroundings.Fish makes a significant effection on the energy moving, circl of material and ecological balance in the system.It also has effected the aquatic productivity and the improvement of economical benefits.However,agricultural chemicals releasing to water has effection on the aquatic system during the several tens of years.It can enter into water-bodies by the ways of surface water runoff,eluviation,dry or wet sedimentations,and so on,influencing directly the vascular bundle hydrophytes and floating algae and it also producing toxicological effects on aquatic animals like fishes at the same time.Recently,a great deal of attention has focused on atrazine for its large use,long persistence,high detection ratio in natural water-bodies and endocrine disruption and so on.So it is consideration to evaluate the water ecological safety of agricultural chemicals.DDVP and Cyfluthrin is the frequent pollutant in the water-bodies,the experiment used grass carp as the trier,and researched the biotoxicity of the agricultural chemicals to grass carp, included acute toxicity experiment and subacut acute toxicity experiment.Acute toxicity experiment detected the acute toxicity of the agricultural chemicals,subacute acute toxicity experiment researched the influence of pollutant to grass carp's AKP,AChE,AST and ALT activities.Following are the main results obtained in the experiments:1.acute toxicity experimentUsed method of static state and treated the data with Bliss statistical method,96hours' half lethal concentration of DDVP and Cyfluthrin on grass carp were 21.9mg/L and 1.125μg/L,safe concentration were 2.19 mg/L and 0.1125μg/L.So we could reach a conclusion that the magnitude of toxicity is Cyfluthrin>DDVP.2.Subacute acute toxicity experimentSet up 4 experiment groups and 1 control group on the base of 96hours' half lethal concentration and safe concentration.The experiment carried out 10 days,the experiment liquor could be replaced by new liquor every day.The samples were gathered at 1th,2th,3th,5th and 10th day.The result testified,the effect of DDVP and Cyfluthrin on the AKP activities of grass carp liver and kidney were inhibition,and the inhibition effect increased with the increase of concentration and the extension of exposure time.The AKP activities of grass carp liver reached minimum value at 10th day,in which the suppression ratio of 20 mg/L DDVP was maximum and reach 95.50%.AKP activities of grass carp liver and kidney were iduced at low concentration.There were no significant differences(P＜0.05) with that of the control group.DDVP and Cyfluthrin could significantly make AChE activities of grass carp liver and kidney. AChE activities in liver and kidney were induced strongly at low concentration during the experiment;and,what is more,the inducement effect increased firstly and then decreased with extension of exposure time,and AChE activities of that above maintained in a level just having feeble changes finally.AChE activities were inhibited at high concentrations at the end of test.The AChE activities of grass carp liver and kidney reached minimum value at 10th day,and the strongest inhibitive rate achieved above 80%in 20 mg/L DDVP and 0.8μg/L Cyfluthrin.The activities of ALT and AST in liver and kidney increased in the initial exposure days,and then declined with increase of DDVP and Cyfluthrin concentration and extension of exposure time, suggesting that the changes of enzyme activities correlated to the DDVP and Cyfluthrin concentration and the exposure time.It is concluded that DDVP and Cyfluthrin exposure can result in changes of the physiological and biochemical indexes and subsequently damage the physiological function of grass carp.At the same time,the significant change of the indexes chosen in the research and the dose-reponse or time-response relationships between DDVP,Cyfluthrin and the indexes showed they were likely to become biomarkers to estimate DDVP and Cyfluthrin pollution in water-bodies.