Experimental Study On Behavior And Toxicological Effects Of Phenol On Zebrafish

With the accelerated process of industrialization,the types and quantities of organic matter is increasing,and not only do organic pollutions cause water environmental degradation,but also risk human and aquatic organisms health. Zebrafish as a model organism,phenol contaminated water,with water quality and safety line biological early warning system (BEWs) and water toxicity bio-line monitor (RTB),zebrafish locomotor activity changes are monitored real-time online under the stress of phenol,and combined with toxicological effects of zebrafish to analyze the correlation between the zebrafish behavior changes and toxicology index after exposuring to phenol.Experimental study contents and conclusions are as follows:(1) Acute toxicity experimental studys of phenol on zebrafish were carryed out with semi-static test method,obtaining LC50 of different times.The results showed that phenol was a medium toxic substance to zebrafish,LCso-48h,LC50-96hwere 18.548,13.554mg/L,and safe concentration was 1.355mg/Lof phenol to zebrafish; compared with the LCso-96h of phenol to other fishes,the tolerance abilities of phenol to zebrafish were lower,and the sensitivities were higher.Under 30,40,50mg/L phenol stress, the time of the zebrafish mortality rate reached 100% were 48,12,12h, and 12,24,48,96h mortality rate waere 53%,66%,86%,27%.(2) Based on the acute toxicity tests of phenol to zebrafish,monitoring the behavior changes of the zebrafish under the stress of phenol by using the principle of signal wave,the effects of phenol and the comprehensive behaviors of zebrafish were analysed.From the test results could be known that throughout the test period, the behavior intensitys of zebrafish were significantly decreased in 0.18-36mg/L groups(p<0.05).When the concentration of phenol was 0.18mg/L (0.01TU) and the above,it could realize the alarm of water pollutions by analyzing the behavior intensity changes of zebrafish in 48h.Compared with the low concentration test groups (0.18,0.9mg/L), the time of reaching the most value of zebrafish behavior intensity were ahead of about 1h in the high concentration groups(18,36mg/L),the behavior intensity tending to stable also extended 10h.(3) Swimming behaviors (swimming speed, swimming height),communication behaviors(communication distance,communication dispersion) and other sporting behavior parameters of zebrafish under the stress of phenol were monitored online by using the principle of moving image monitor,and water quality health index was responsed.The results showed that differences of water quality health index between the control group and low concentration (0.18,0.9mg/L), general concentration (1.8,9mg/L),high concentrationtest groups(18,36mg/L) were 15%,20%,30%.The differences of water quality health index were significant between the control groups and the experimental groups(p<0.05),and the change trend was consistent with BEWs.Compared with the low concentration,the time of peak value of zebrafish swimming behaviors and communication behaviors were shortened by 1-2h,2-4h in high concentration experimental groups(18,36mg/L).The time of peak value of swimming was more 1-2h than swimming speed,swimming speed of zebrafish under the stress of phenol was more sensitive than other indicators,swimming speed could be selected as abnormal behavior index of monitoring phenol pollution.(4) Toxicological effects of phenol to zebrafish were studied.Through studying the changes of the activities of ATP enzyme,acetylcholinesterase(AChE),superoxide dismutase(SOD),catalase(CAT)of zebrafish in experimental groups,the correlation of movement behavior changes and toxicological effects under the stress of phenol was explored.The results showed that,compared with the control group,ATP, AChE, SOD and CAT activities increased respectively by 10-18%,20%,0.5-8% in low concentration groups(0.18,0.9mg/L) during the early stage(6h)under the stress of phenol,presenting toxic excitatory effects.Short time stress, enzyme activities could be induced by phenol, with the extension of exposure time, induced weakened and even inhibition;with the concentration of phenol increasing, ATPase and AChE activities decreased gradually, and the activities of SOD and CAT gradually rise.Due to the lag effect of reaction, time of reaching the peak of CAT activities was lagged of about 24h than SOD in 0.18-36mg/L six test groups.A variety of biological enzyme activities were effected by phenol,which led to changes in the nervous system,brain,muscle and organ function, thereby affecting the behaviors of animals,and there was a significant dose effect relationship between the intensity of exercise behaviors and the activities of enzymes to zebrafish.