| Copper is a transition element abounds in nature, a nutritional elementrequired by all aquatic animals and a main component of many enzymes (such as lysyloxidase, superoxide dismutase and cytochrome C oxidase etc.). But it can be inhibitory andtoxic in excess concentrations. Because it can not be decomposed or eliminated in theecosystem, so it is widely concerned by the environmental science community. In recentyears, with the extensive use and the high addition of copper sulfate in aquaculture andaquatic feeds, copper pollution is more and more serious. Waterborne copper toxicities andbioaccumulation, elimination patterns have been studied in numerous species of fish becauseof the higher toxicity and toxicity range of dissolved copper.Yellow River carp (Cyprinus carpio) is one of the highest value aquaculture species in thenorth of China. In order to study the copper toxicity and tissue copper accumulation andelimination pattern on copper of Yellow River Carp (Cyprinus carpio), first the Yellow RiverCarp was tested in the static water to evaluate the safe concentration on copper, acutepathological changes, the change of antioxidant enzyme activity in liver, and the content ofcopper enrichment after expose to copper96hours. Seven treatments (0.00,0.08,0.16,0.32,0.63,1.26,2.51mg/L) in duplicate were tested. The results showed that:(1) At temperature24±1℃, pH7.4±0.1, copper was toxic on the Yellow River carp.(2) The median lethalconcentration of24,48,72,96h was5.02mg/L,2.77mg/L,1.66mg/L,1.12mg/L, The96h safe concentration value was0.112mg/L.(3) The concentration of copper in blood andmuscle increased at frist, then stable changed; the concentration of copper in gills increasedat frist, but then decreased, increased; the concentration of copper in kidney increased at frist,then decreased to stable. But the concentration of copper in liver increased all the time, withthe copper concentration increases.(4) The gill, liver. kidney. muscle, brain, spleen and heartof Yellow River carp all had pathological changes on copper and with the copperconcentration increases, the pathological changes were more serious. The changes containthe degeneratable necrotic foci in liver and Sticks-like gill lamella hyperplasla.(5) With thecopper concentration increases, the activity of CAT in liver frist rose, then reduced, theactivity of T-SOD and Cu-Zn SOD in liver frist rose, then reduced and rose, then reducedagain, then rose; And the content of MDA in liver continue to rise. Secondly the Yellow River Carp was tested in the changed water to study the change ofantioxidant enzyme activity in liver at different time after different waterborne copperconcentration expose of subacute toxicity test and the tissue copper accumulation andelimination pattern during and after different waterborne copper concentration expose ofacute toxicity test. Six treatments (0,0.32,0.48,0.72,1.10,1.66mg/L) in duplicate weretested in subacute toxicity test. The results showed that: With the extension of expose time,the activity of T-SOD and Cu-Zn SOD in liver frist rose, then reduced; The activity of CATin liver frist rose, reduced, then rose again; But the content of MDA in liver continue to rise.During the same time, The activity of the three enzyme in liver and the content of MDA inliver had no law with the extension of time. Seven treatments (0.00,0.21,0.30,0.43,0.60,0.81,1.06mg/L) in duplicate were tested in acute toxicity test. The results showed that:(1)In the17ds accumulation test, With the extension of expose time, copper content of bloodchanged fluctuated; the gills, kidney and muscles copper content of each group reach tobalance on the different day; copper content of liver was sustainable growth. On the17thday,with the copper concentration increases, copper enrichment of gills and kidney had nodifferent, copper enrichment capability of liver and muscle was the opposite, the blood tocopper enrichment has no law.(2) During the17ds emission test, with the extension ofexpose time, copper content of blood changed fluctuated; The gills, kidney and musclescopper content of each group reached to balance on the different day; Copper content ofliver was stainable growth. To the end of the test, the order of the average discharge ratewere gill> muscle> blood> kidney.(3) The results indicated: the copper on the YellowRiver carp is high toxic; The order of the copper enrichment capability on Yellow River carpwere: hepatopancreas> gill> kidney> muscle; Copper enrichment content in tissues of theYellow River carp in this discharged time not only cannot be completely discharged, butliver copper content would be continue to rise. |
PDF Full Text Request