Two Heavy Metalcobalt And Nickel's Toxicity Effects On Two Different Loaches

In recent years,with the growing prominence of food safety problems,rice pollution has become one of the main pollution problems,chemical plant emissions of a large number of waste liquid containing heavy metals through various channels into the rice fields,through the food chain into the human body,which endangering human health.The "three wastes" damage aquatic organismswhich is becoming more and more serious,people gradually pay attention to it.In this study,regardingtwo different loaches as subjects,through acute test,micronucleus test,single cell gel electrophoresis assay,embryo toxicity test,physiological tests and histological sections of several parts to study heavy metal?cobalt ion and nickel ion?toxicity on M.anguillicaudatusand P.dabryanus.The two kinds of heavy metals?cobalt ion and nickel ion?on aquatic toxicity effects of these contents have not been entirely discovered and provideshardly reference data.Acute experiment results show that the cobalt ion's24h,48 h,96h median lethal concentration(LC₅₀)of M.anguillicaudatuswere 281.838 mg/L,181.97 mg/L,139.316 mg/L,the safety concentration?safe concentration?of M.anguillicaudatuswere 22.76mg/L.The cobalt ion's 24 h,48h,96 h median lethal concentration(LC₅₀)of P.dabryanuswere 381.0658 mg/L,202.302 mg/L,149.624 mg/L.the safety concentration of P.dabryanuswere 17.105mg/L.The nickel ion's 24 h,48h,96 h median lethal concentration(LC₅₀)of M.anguillicaudatuswere 456.0369 mg/L,356.451 mg/L,275.42 mg/L,the safety concentration of M.anguillicaudatuswere 65.3312 mg/L.The nickel ion's 24 h,48h,96 h median lethal concentration(LC₅₀)ofP.dabryanuswere 365.595 mg/L,285.759mg/L,228.560mg/L,safety concentration ofP.dabryanuswere 52.375 mg/L.Single cell gel electrophoresis and micronucleus test results showed that the two heavy metal in loach cells caused damage.The test results show that two kinds of heavy metals in loach blood cell's nuclear anomalies rate compared with the control group which have different degrees of improvement.In the micronucleus test,cobalt ions on the rate of abnormal nucleus can reach 59 in the highest concentration,nuclear anomalies can reach 61 in the highest concentration,nickel ionscan reach 67 on the rate of abnormal nucleus in the highest concentration,abnormal rate of nuclearcan reach 72 in the highest concentration.It is not hard to see that the nickel ion can induce the red blood cell to produce the abnormal nucleus.In the single cell gel electrophoresis,three index in blood cells and liver cells were increased with time and dose.The toxicity of cobalt on M.anguillicaudatus' three values: tail DNA content was 74.35 ±7.60,tail length was 348 ± 5.66,tail moment was 158.56 ± 0.17,respectively.It is not difficult to find these two kinds of heavy metals have certain genetic toxicity on M.anguillicaudatusandP.dabryanus.In order to test physiological toxicity of two metal ions on M.anguillicaudatus,we selectSOD,CAT,GSH,MDA as the four indicators to research this area.The results showed that two kinds of metal ions can induce oxidative stress in loach,the liver detoxification capacity decreased,which results in liver failure.In the embryo toxicity test of larvae's acute toxicity test showed that the cobalt ion's24h,48 h,96h median lethal concentration(LC₅₀)ofM.anguillicaudatus were 23.4531 mg/L,13.8516mg/L,6.2980mg/L the safety concentration was 1.4495mg/L,nickelion's 24 h,48h,96 h median lethal concentration(LC₅₀)ofM.anguillicaudatus were 23.7137 mg/L,14.454 mg/L,6.4165mg/L?safe concentration?,the safety concentration was 1.611mg/L.The cobalt ion's 24 h,48h,96 h median lethal concentration(LC₅₀)ofP.dabryanuswere 26.3876mg/L,14.1416 mg/L,2.3818 mg/L,the safety concentration was 1.2185 mg/L.The nickel ion's 24 h,48h,96 h median lethal concentration(LC₅₀)ofP.dabryanus were 26.3877 mg/L,13.1947mg/L,2.4998mg/L,the safety concentration was0.9897 mg/L.Two kinds of metals induced embryonic malformation rate and embryonic mortality as the observation object,studying the four periods of embryonic development of the two different loaches,which is in order to determine the embryo toxicity of two kinds of metals on M.anguillicaudatusand P.dabryanus.In the highest concentration of cobalt ions,the two values of the deformity rate were 40.68% and 41.58%,respectively,while in the highest concentration of nickel ions,the two values of the deformity rate reached 57.88% and 45.58%,respectively.The results showed that two kinds of metals really had some embryonic toxicity to the subjects.In the study of tissue morphology,based on acute toxicity test,we extracted in Loaches' Liver,skin,intestine,ovary and testis,the results showed that liver,testis,ovary with increasing concentration compared with the control group,the occurrence of certain changes in the morphology and structure but in the intestine and skin,this change is almost not obvious.