e (DMSP) in marine（DMSP）在海洋 桡足类和它的关系与diets 和盐分剖面 1、Vol.179:71-79.1999MARINEECOLOGYPROGRESSSERIESMarEcolProgSerPublishedApril15Dimethylsulfoniopropionate(DMSP)inmarinecopepodsanditsrelationwithdietsandsalinityKamW.Tang*,HansG.Dam,PieterT.Visscher,TimothyD.FennDepartmentofMarineSciences,UniversityofConnecticut,Groton.Connecticut06340,USAABSTRACT:Themai 2、ngoalofthisstudywastoassesstheeffectsofalgaldetsandwatersahityonthebodilycontentofdimethylsulfoniopropionate(DMSP)inestuarinecopepods.Inlaboratoryexperi-ments,TemoralongicorniscontainedmoreDMSPwhenfedDMSP-richTetraselmisimpellucida(prasinophyte)thanwhenfedDMSP-poorDunaLiellatertiolecta(chlorophyte).T 3、heDMSPcontentofT.longicornisaftergutclearancewascurvilinearlyrelatedtotheingestionrate.Theseobservationssug-gestthatthecopepodsincorporatedthedietarysourceofDMSPintotheirbodytissue.Onthesamediet,T.longicorniscontainedmoreDMSPathighersalinity,indicatinganosmoregulatoryfunctionofDMSP.However,DMSPappear 4、stobeaminorosmolytecomparedwithfreeaminoacids.TheDMSPcontentofT.longicornisdecreasedfasterinresponsetoadecreaseinsalinitythanitincreasedwithanincreaseinsalinity,implicatingseparatemechanismsforaccumulationandremovalofDMSPinthecopepod.WealsomeasuredthebodilycontentofDMSPfromfield-collectedanimals.Five 5、speciesofcalanoidcopepodsfromLongIslandSoundcontainedDMSP,notassociatedwithgutcontent,whichvariedinterspecificallyfrom0.02to1.03nmolind:Carbon-specificDMSPcontentofthecopepodswascomparabletothatreportedforsomediatoms,chlorophytesandcryptophytes.Wearguethatcope-podbiomassmay,attimes,representsasubstan 6、tialsourceofparticulateDMSPinthewatercolumn.KEYWORDS:DMSP.Copepodbiomass.Diets.Salinityshift.OsmoregulationINTRODUCTIONDimethylsulfoniopropionate(DMSP)isagloballyimportantsulfurcompoundbecauseitcanbebrokendownchemicallyandbiologicallyintodimethylsulfide(DMS)(DaceythehypothesisthatDMSPisusedasanosmoly 7、teinzooplanktonhasnotbeenstudied.Inthepresentstudy,wetestthehypothesesthat(1)marinecopepodscontainDMSPindependentlyofgutcontents,(2)theDMSPcontentofcopepodsisdeter-minedbytheirdiet,and(3)copepodsuseDMSPforosmoregulation.WeshowthattheamountofDMSPincopepodsdependsonfoodtypeandfoodconcentra-tionaswellas 8、externalsalinity.Furthermore,wereportthepresenceofDMSPincopepodbiomassandassessthecopepodcontributiontothetotalDMSPpoolinLongIslandSound.MATERIALSANDMETHODSDMSPinfield-collectedcopepods.CopepodsandsurfaceseawaterswerecollectedfromeasternLongIslandSound(41“1826“N,70“0327“W)betweenMayandOctoberof1997wi 9、thastandardringnet(0.5mmouthdiameter,202pmmeshwithasolidcodend).Uponreturntothelaboratory,thecopepodsweresortedbyspecies.DMSP
