西部和中部北太平洋海域灰鲭鲛

Ageandgrowthanalysisoftheshortfinmako,Isurusoxyrinchus,inthewesternandcentralNorthPacificOcean西部和中部北太平洋海域灰鯖鮫之年齡成長分析YasukoSemba&HidekiNakano&IchiroAokiEnvironBiolFish(2009)84:377–391speaker：陳怡婷ShortfinMakoKingdomAnimaliaPhylumChordataClassChondrichthyesSubclassElasmobranchiiOrderLamniformesFamilyLamnidaeGenusIsurusSpeciesoxyrinchus中文名灰鯖鮫圖片來源=Isurus%20oxyrinchus資料來源=order00IntroductionBiology•Habitats:Ocean、DeepSea、Coastal•HabitatsDepth:0-740M•MaxLenth:400cm•Sizeatbirthestimatedtobeabout60-70cminTL.•Ovoviviparous,withauterinecannibal.高級消費著消費者生產者=752r-organismsK-organismsshort-livedlong-livedsmalladultsizelargeadultsizeweakstrongorwell-protectedwastealotofenergyenergyefficienthavelargelittershavesmalllittersreproduceatanearlyagereproduceatalateagefastmaturationslowmaturationstrongsexdriveweaksexdrivesmallsizeatbirthlargesizeatbirthCharacteristic•Widedistribution,andpreferstemperaturesof17to22°C.(CaseyandKohler1992)•Migration•Sexual/ontogeneticstagesegregationDistribution資料來源•Therecentandrapidcollapseoflargepredatoryfishpopulationsisaglobalconcern(MyersandWorm2003,2005).•Informationonlifehistoryparametersderivedfromageandgrowthanalysesplaysanintegralrole.Agedeterminationisanimportantcomponentofpopulationanalyses.•Inaddition,thegrowthcurvesgeneratedinthisstudywerecomparedtothoseforpopulationsinothergeographicregions.MaterialsandmethodsSamplecollection•Samplingperiod:1992~2005bytheJapaneseresearchvesselsandtunalonglinetrainingvessels.•Samplingamount:275individuals(128malesand147females).•Samplingsite:westernandcentralNorthPacificOcean.Fig.1Samplinglocationsfortheshortfinmako(Isurusoxyrinchus)inthewesternandcentralNorthPacificOcean.Eachpointdenotesapositionwheresampleswerecollected.Fig.2Lengthfrequencyofthespecimenusedfortheanalysisspecies.wikimedia.org/.../Images/testPCL(cm)TL(mm)DL(mm)FL(mm)DL,TL,FLwithPCLPCL:57.2to186.5cmStepSexdeterminationMeasurePCLExcisethevertebralcolumnabovethegillslitsFrozethevertebralcolumnat−40°CVertebralprocessingBoilthevertebraeStoreitin70%ethanolCutoffasinglecentrumSoakitin6NNaOHScrubitwithapolishingbuffEachcentrumiscutintotwolongitudinalsectionsafterdryingThehalfcutcentrawiththefocuswereusedforanalysisafterwashingawaytheboneparticleanddryingfor1dayFourtechniquestoenhancevertebralgrowthbands1.shadowing(half-cutcentra;FrancisandMaolagáin2000)2.alizarinstaining(section;Berryetal.1977)3.silvernitratestaining(wholecentra;Stevens1975)4.softX-radiography(wholeorhalf-cutcentra;Caillietetal.1983)MethodofagedeterminationshadowingalizarinstainingsilvernitratestainingsoftX-radiographyVertebralhalf-cutcentrasagittalsectionwholecentrawholeorhalf-cutcentraGrowthbandsconvexconcavelightlystained(opaque)deeplystained(translucent)translucentregionopaqueregionSpendingtimeshorttestlongerlongershorteranalysismoreprecisionandclaritylessinformationlessinformationoverestimationTheshadowingmethod1.Simplicity2.Visualclarity3.Relativeabundanceofinformationamount4.Lesstime-consumingprocessFig.3Halfofavertebralcentrumwithlateralilluminationfromfiber-opticsources.Thetrianglesindicateaconvexstructureorgrowthband.Thisexampleisfroma137cmPCLfemale,withavertebralcentrumradiusof9.5cm,andanestimatedageof4.6yearsAgedetermination•Inthisway,theconvexandconcavestructureswereobservedaslightanddarkregions,respectively.Thesestructurescorrespondtotheopaque(convex)andtranslucent(concave)regionsobservedinthesagittalsection.•Thevertebraeofneonates,whichdisplayedonlyabirthmark,wereexcludedfromthisanalysis.CRwithPCL•Thecentrumradius(CR)isthedistancefromthefocustotheedgeofthecentrumperpendiculartothedirectionofthecuttingplane.TheCRwasmeasuredtothenearest0.01mmCRFig.6Age-biasplotof275shortfinmakovertebralcountsfromtwoindependentreadingsbythefirstauthor.Theopenandsolidmarkindicatetheobservedcountsandthemeancountsassignedbythesecondcountforallfishwhichwasassignedagivencountinthefirstcountupto12,respectively.Theverticalbarsforthesolidmarkuptothefirstcountof11indicatethe95%confidenceinterval.Theonetooneequivalencelineisalsorepresented.PA=[No.agreed/No.read]*100Assumingthatannuli(convexstructures)areformedsoonbeforeorafter1December,ageinyearswascalculatedasfollows:x=thenumberofconvexstructurey=themonthwhentheindividualwascaught(1≤y≤12).Lt=PCLattimet(cm)L0=sizeatbirth(cm)(74cmTL)(JoungandHsu2005)L∞=asymptoticlength(cm)K=brodygrowthconstant(year−1).VBGEwithsizeatbirthResultsMale:53~240cm(PCL)Female:57~300cm(PCL)theallometricequationforregressionanalysisAkaike’sInformationCriterionAIC=nln(MSE)+2K•modelN(nobandperiodicity):312.44•modelA(annualperiodicity):271.89•modelB(biannualperiodicity):316.24Theestimatedgrowthequationst=age(years)TheestimatedS.E.ofL∞forfemaleswaslargerthanthatformales,whileS.E.ofKformaleswaslargerthanforfemalesDiscussionGrowthFig.7EstimatedvonBertalanffygrowthcurvesforfemaleandmaleshortfinmakointhew