Mercury(Hg)isoneofthecommonlyencounteredheavymetals,whichiswidespreadininshoresedimentsofChina.InordertoinvestigatethetoxicityofHgonmarineinvertebrates,westudiedtheeffectsofthepalentmercuricion(Hg2+)(attwofinalconcentrationsof0.0025and0.0050mgL-1,preparedwithHgCl2)onmetallothionein(MT)content,DNAintegrity(DNAstrandbreaks)andcatalase(CAT)inthegillsandhepatopancreas,antioxidantenzymeactivitiesofsuperoxidedismutase(SOD),catalase(CAT)andglutathioneperoxidase(GPx),inthehemolymph,gillsandhepatopancreasoftheportunidcrabCharybdisjaponicaforanexperimentperiodupto15d.TheresultsindicatedthatMTwassignificantlyinducedafter3d,withapositivecorrelationwithHg2+doseandtimeinthehepatopancreasandanegativecorrelationwithHg2+doseandtimeinthegills.WhileCATinthehemolymphwasnotdetected,itincreasedinthehepatopancreasduringtheentireexperiment;SODandGPxinthethreetissueswerestimulatedafter12h,bothattainedpeakvalueandthenreducedduringtheexperimentalperiod.Meanwhile,DNAstrandbreakswereallinducedsignificantlyafter12h.TheseresultssuggestedthedetoxificationstrategiesagainstHg2+inthreetissuesofC.japonica.
