Mollusks:amongthefirstcoelomatesExtremelydiverseanimalphylum,secondonlytoarthropods200,000speciesExhibitavarietyofbodyformsandliveinmanydifferentenvironmentsIncludesnails,clams,scallops,oysters,cuttlefish,octopusesandmanyotherfamiliaranimalsRangeinsize:mostafewcmGiantsquid:21mlong,250kg;giantclam:1.5mlong,270kgMollusca(軟體動物門)Un-segmentedbody,bilaterallysymmetricalSoftbodyenclosedinacalciumcarbonateshellVisceralmass(內(nèi)臟團):digestive,excretory,andreproductiveorgansMosthaveahead(eyesandothersensoryorgans)Bodyiscoveredbyamantle(外套膜)athinlayeroftissueOutersurfaceofmantle:secretaprotectiveshellPairedgills:specializedportionsofmantle,usu.Asystemoffilamentousprojectionsrichinbloodvessels,gasexchangeShell:primarilyforprotectionthreelayers

Ahorny/角質(zhì)outerlayer:richinprotein,protectthetwounderlyingcalcium-richlayersfromerosion

Middlelayer:denselypackedcrystalsofcalciumcarbonate

Innerlayer:pearlyandincreaseinthicknessMollusca(軟體動物門)Mollusca(軟體動物門)Aventral,muscularfoot:adaptedforlocomotion,attachment,foodcapture(insquidsandoctopuses)Radula(齒舌):unique,aribbonofdozenstothousandsofmicroscopic,chitinous(幾丁質(zhì))teetharrangedinrowsCirculatorysystem:aheartandanopensystem(bloodcirculatesfreely),(exceptcephalopods)Coelom:asmallcavityaroundtheheartModifiedInternalshellinsquids;absentinoctopusesandafewothergroupsSnails:coiledbodyandasymmetricalRadula:somemodifiedorevenabsentGeneralizedmolluscanbodyplan腎管GeneralbodyplanofasnailEsophagus:食管salivarygland:唾液腺Operculum:厴ReproductioninmollusksMosthavedistinctmale&femaleindividuals,afewbivalves&gastropodsarehermaphroditic/雌雄同體，(cross-fertilization)Someseaslugs&oysters:abletosexreversalMost:externalfertilization;gastropodsmoreoftenhaveinternalfertilization(oneofthekeyadaptationsallowthemtocolonizetheland)Trochophore(擔(dān)輪幼蟲)Planktonic(free-swimming)lavalstageofmanymarinemollusksandotherinvertebratessuchasannelidsSwimbymeansofarowofciliaencirclesthemiddleofbodyVeliger(面盤幼體)Asecondfree-swimmingstageinmostmarinesnails&bivalvesHasthebeginningofafoot,shell,andmantlelarvaedriftwidelyinoceancurrents,dispersingtonewareasTypesofMolluscsGastropods(Gastropoda腹足綱)Bivalves(Bivalvia雙殼綱)Cephalopods(Cephalopoda頭足綱)OthermolluscsPolyplacophora/多板綱Chitons/石鱉BodyplansamongthemollusksGastropoda腹足綱Most:useradulatoscrapealgaefromrocksSome:depositfeedersSome:carnivoresAllshapes,colors,andhabitsa:giantkeyholelimpet(笠貝),encrustingredcorallinealgaeb:redabalonec:coneshell

(錐螺),carnivoroussnaild:nudibranch(裸鰓類)TerrestrialsnailBivalvia雙殼綱Clams,mussels,oysters,andsimilarmolluscsBody:laterallycompressed,enclosedinatwo-valveshellNohead,noradulaGills:usednotonlytoobtainoxygenbutalsotofilterandsortsmallfoodparticlesfromthewaterBivalvesMost:burrowersMussels:secretstrongbyssal(足絲)threadstoattachthemtorocksandothersurfacesOysters:cementtheirleftshelltoahardsurface(oftentheshellofanotheroyster)Somescallops:liveunattached,canswimforshortdistancesBivalvesGiantclam:thelargestclam,>1minlengthPearloysters:secretshinylayersofcalciumcarbonatetocoatirritatingparticlesShipworm(船蛆)SymbioticbacteriaintheirgutdigestthewoodAnexampleofafoulingorganism(污損生物)Cephalopoda頭足綱Predators,specializedforlocomotionOctopuses,squids,cuttlefishes,andotherfascinatingcreaturesAgileswimmerswithacomplexnervoussystemandareductionorlossoftheshellNearlyclosedcirculatorysystem650species,allaremarineOctopusEightlongarms(八爪魚),thetipofthethirdrightarminmaleismodifiedtotransferpacketsofspermLackashell,commonbottomdwellersSizesvariesfrom5cm(dwarfoctopus)toarecordof9m(Pacificgiantoctopus)Secretaparalyzing(麻痹)substance,somehighlytoxic(藍環(huán)章魚),butmostharmless魷魚（槍烏賊）：十腕目，尾端尖似槍頭墨魚（烏賊）：十腕目，能噴墨，內(nèi)骨大羽狀殼Nautilus/鸚鵡螺Nautilus(鸚鵡螺)UnusualexternalshellCoiledandcontainsaseriesofgas-filledchambersChambersarewalledoffonebyoneastheanimalgrowsAnimallivesonlyinthelastchamberOtherchambersfilledwithgasandprovidebuoancyRatherthanpumpinggasin,Nautilusremovesalltheionsfromthewaterinthechambertomakewatermoredilutethananimal’sblood.SothewaterflowsintothebloodstreambyosmosisandgasdiffusesintochambertoreplaceitShellmayupto25cmindiameter60to90shortsuckerlesstentaclesusedtocapturepreyOtherMolluscs~800speciesofchitons(石鱉,Polylacophora多板綱),allmarineEightoverlappingshellplates~350orsospecieoftuskshells(角貝),orscaphopoda(掘足綱)MostcommonindeepwaterEmptyshellssometimeswashashoreArthropods:mostdiverseofallanimalgroupsTwomoreinnovationsarose:jointedappendages&exoskeletonPhylumArthropoda:mostdiversephylum節(jié)肢動物門/ARTHROPODSLargestphylumofanimalsmorethanamillionspeciesdiscoveredseveralmillionsundiscoveredMerostomata/肢口綱，如鱟Arachnoida/蛛形綱，如蜘蛛Crustacea/甲殼綱，如對蝦Myriapoda/多足綱，如蜈蚣Insecta/昆蟲綱，如蝴蝶Tirlobita/三葉蟲綱，已滅絕甲殼動物/crustaceans

68000多種甲殼動物/crustaceansCopepods/橈足類Barnacles/藤壺Amphipods/端足類Isopods/等足類Krill/磷蝦類Shrimps/蝦類Lobsters/龍蝦類Crabs/蟹類Hermitcrab/寄居蟹類68,000speciesknown150,000speciesundiscribedCharacteristicofarthropoda節(jié)肢動物特征Bodysegmentedandbilaterallysymmetrical體分節(jié)，兩側(cè)對稱Bodyflexibleandjointedappendages體可彎曲，各節(jié)有附肢Tough,non-livingexternalskeleton-exoskeleton外被堅硬、無活性的外骨骼—外甲（甲殼）Mustmolttogrow體需先蛻皮再增長㊣Characteristicofcrustacean

甲殼動物特征Majorityofmarinearthropods海洋節(jié)肢動物的主要類群Specializedforlifeinwater幾乎終身生活水中twopairsofantenna有兩對觸角Gillforbreathe鰓呼吸Chitinousskeletonhardenedbycalciumcarbonate甲殼為碳酸鈣硬化的幾丁質(zhì)Appendagesforswimming,crawling,mating,feeding,attaching附肢用于游泳，爬行，交配，攝食和打斗morphologyofcrustacean甲殼動物形態(tài)結(jié)構(gòu)Nomenclature/學(xué)術(shù)名詞Cephalothorax/頭胸部Abdomen/腹部Telson/尾部Antenna/觸角Maxillipeds/顎足Pereiopods/胸足、步足Pleopods/腹足、游泳足Uropods/尾足Cheliped/螯足Claw/鉗、螯Appendage/附肢Brain/腦Mouth/口Stomach/胃Heart/心臟Nervecord/神經(jīng)索Gonad/性腺Gonadduct/性腺管Testis/精巢Intestine/腸道Anus/肛門Digestivegland/消化腺Maingroupofcrustacean甲殼動物主要類群smallcrustacean(plankton)Copepods/橈足類Barnacles/藤壺Amphipods/端足類Isopods/等足類Krill/磷蝦類Largecrustacean(swimming,crawling)Shrimps/蝦類Lobsters/龍蝦類Crabs/蟹類Hermitcrab/寄居蟹類Copepoda/橈足類AbundantandimportantplanktonFilteroutorcapturefoodEnlargedfirstantennaekeepfromsinkingManyspeciesareparasiticBarnacles/藤壺類BodyenclosedbycalcareousplatesAttachingtosurfacesincludinglivingsurfaceFilterfeederFoulingorganismTypicalcrustaceanlarvaeAmpipods/端足類Over5000speciesCurvedbodyflattenedsidewaysHeadandtailcurveddownward2-3cmcommonlyDeep-seaspecieslargerHoppinginshoredebrisCrawlingamongseaweedsBurrowinginskinofwhalesIsopods/等足類BodydorsoventrallyflattenedwithflatbackLivingenvironmentandsizesimilartoamphipodsAsfishlouse(lice)parasitizingfishesetc.Krilloreuphausiids/磷蝦類ShrimplikeplanktonBody<6cmCarapacecoveringanteriorhalfofthebodyFilterfeedingAggregatingingiganticschoolsofbillionsofindividualsExclusivefoodforAntarcticwhales,penguinsandfishesShrimp/蝦類LargestcrustaceansinsizeGreateconomicimportanceDecapods:fivepairsoflegsorpereopodMainlyscavengeElongatedabdomenFivepleopodsforswimmingSometropicalandcolorfulshrimpremovingparasitesfromskinoffishLobster/龍蝦類CarapacewelldevelopedascephalothoraxThreepairsofmaxillipedsforfeedingElongatedabdomenFiveswimminglegsundevelopedMainlycrawlingSomespecieslivinginland

forshorttimeCrab/