OhIlovelearningaboutSponges!!!
Objectives
• AconfidentscientistcanidentifyallcharacteristicsthatclassifythephylumPorifera
• Aconfidentscientistcanlabelthemajorpartsofthesponge• Aconfidentscientistcanmodelhowspongeseat,breath,andreproduce
INTRODUCTION TO PORIFERA (AKA Sponges)• Originally thought they were aquatic plants• Now known as ancient animals with fossils
dating back to PreCambrian (>500 mya)• Over 5,000 species of extant sponges today
Section21.2 Sponge: © Getty Images RF; sea sponge: ©Laurence F Tapper/YAY Micro/age fotostock RF Figure21.9
Spongesarediversewith3majorvarieties
Tubesponges
Basket/Fansponges
Brainsponges
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PoriferaClassification•PhylumPorifera
• ClassCalcarea(calcareassponges)
• ClassDemospongiae• ClassHexactinellida–glasssponges
Taxonomic Detail
Desmospongia
All other classes
Donotworryaboutothertwoclassesofsponges
Section21.2 Figure21.9
KeyFeatures
SpongesLackDifferentiatedTissuesPhylum Porifera:Sponges
Thinkofspongesascolonyofprotozoansorcolonyofspecializedcells.Therearenonervecellsorothermeansofcoordinationbetweencells
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Porifera:Characteristics•Notruetissuesororgans(onlyspecializedcells)•Mostareasymmetrical, butsomemayberadial• Sacbodyplan•Diploblastic-meaning2germlayers• Porifera meansporebearing (bodywallpiercedbynumerousporesforwatertoenter)
•Reproducesexuallybyfertilization andasexuallybybudding
• SkeletonscomposedofCaCO3 spicules orspongin(proteinfibers)
• Centralbodycavityislinedw/collarcellscalledchoanocytes
Poriferansare…• Simplestformofanimal• Bodywithcellsarrangedaroundpores,canalsandchambersforthepassageofwater.
• Skeletalstructureofspiculesand/orspongin.
• Filterfeeders.
Poriferansare…• Sexualandasexualreproduction.• Bodiespiercedalloverwithopeningscalledpores
• Aresessileandattachedtosubstrateorobjects- occasionallyonotheranimalssuchascrabsbuthaveplanktoniclarvae
PoriferadoNOThave…
• Anorgansystem• Nervoussystem• Muchco-ordinationbetweencells
• Tissueorganization(somebutveryrestricted)
• Symmetry(somehaveradialsymmetry
• Atruebodycavityorgut
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PoriferaAnatomy•Notruetissues•Consistsofspecializedorganizedcellssupportedbyaskeletonof:-sponginfibers-calcareousspicules-silicaspicules-combinationofthese,ornoskeletalstructureatall
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PoriferaAnatomy
CollarCells
•Choanocytes:(collarcells)actasapumptobringwaterintothesponge
Phylum Porifrea14
Spicules
• Spicules:skeletonstructures,madeofcalciumcarbonate(CaCO3)
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SpongeSupport
• Mesoglea isatranslucent,non-living,jelly-likesubstancefoundbetweenthetwoepithelialcelllayers(ex.Btwectoderm&endoderm)
Mesoglea
HowdoSpongeseat&breathe?• Choanocytescollectfoodfromwatercurrentspassingthoroughporousbody
• Foodisdigestedbychoanocytes orpassedontoamebocytes
• Amebocytes actasaprimitative andsimplecirculatorydevicetotransportnutrients
• SpongesgetO2bydiffusion.
Spermreleasedfromonespongearetakenbychoanocytesoffemaleactingspongeandengulfedbyamebocytes.Fertilizationoccuresandfreemovinglarva(amphiblastula)developbeforesettlingatbottom
• Softbodieshavenetworkofspikes.• Canreproduceasexually(budding)andsexually.Fertilizedeggsgothroughalarvaestage.
Reproduction
Section21.3 Figure21.10
Diversephylumwithover9,000speciesmostbeingintheocean.
CnidariansBackground
Jellyfish: ©Kevin Schafer/Alamy RF; hydra: ©T. E. Adams/Visuals Unlimited; coral: ©Comstock Images/PictureQuest RF; coral animal: ©Leslie Newman & Andrew Flowers/Science Source; sea anemones: ©Russell Illig/Getty Images RF
Section21.3 Figure21.10
Keyfeatures
CnidariansAreRadiallySymmetricalPhylum Cnidaria:Jellyfish,hydra,coral,andseaanemones
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Cniderian:Characteristics• MosthaveRadialsymmetry• Sacbodyplan• MostCnideriansareDiploblastic,fewareTriploblastic• Firstanimalstohavetruetissues derivedfromgermlayers:Epidermis-Ectoderm&Gastrodermis-Endoderm
• Gastrovasularcavity=digestivecavity• Mouthonly,noanus• Stingingcellscalledcnidoblastswhichcontainnematocysts(toxinfilledcapsules)
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Cniderian:Characteristics•Mosthaveseveralwhorlsoftentaclesaroundtheirmouth• Noelaborateexcretoryorrespiratorysystems• Bothasexualandsexualreproductivestrategies• 2bodyplans:
(1)Polypisfixed&sedentaryw/tentaclesandmouthfacingupwards(2)Medusa- bellshapedthatisfreeswimming with
mouthandtentaclesdirecteddownward
PhylumCnidaria(Jellyfish,SeaAnemones,&Corals)
• 2Forms• Polyp
• Sessileform(tentaclesupward)
• Medusa• Swimmingform(tentaclesdownward)
•Betweenthe2GermLayers
•Mesoglea• Jelly-likesubstanceinbetweeninnerandouterlayerthatactslikeahydrostaticskeletontohelpmaintainitsshape(thinkofwaterballoon)
•GastrovascularCavity(GVC)• Emptyspacewheredigestiontakesplace
PhylumCnidaria (Cont.)
BasicAnatomyofaJellyfish
AnatomyofHydra whichisusedasareexemplar
WhatdoyouknowaboutJellyfish?• Ouchee!!!!!• CnidariacomesfromtheGreekwordnettleasinthestingingnettleplantthatliveshere.
• Whatpartofthejellyfishstingsyou?
PhylumCnidaria•CnidocytesandNematocytes
• Cnidocytes =specializedcellsshapedliketinyharpoons
thatcanstingyouusedfordefense
• Nematocytes =structuresinsidethecnidocytethatcontainstingingfilaments
• Thefilamentshavesharptipsthatcaninjectpoisonintovictims
Section21.3 Figure21.10
CnidariansAnatomy
Whatwouldbeanevolutionaryadvantageofpossessingcnidocytes?
CniderianCnidocyteinAction
CnidocyteinAction!
Pauseandthinkcalmlyonthis…
Likesponges,Cnidarian’stissuesdonotformorganssuchasbrainsormuscles,yetsomehavetheabilitytomoveandfeedonsmallprey.Howcanthisbe?
PhylumCnidaria (Cont.)
•1st NervousSystem
• Poriferahavenodevelopednervoussystem
• Cnidarianshaveaprimitivenervoussystem
• Nobrain,butratheraloosecollectionofnervescalledanervenet
• Nervesradiatethroughoutthewholebody
PhylumCnidaria
PhylumCnidaria•Wheredotheylive?(Habitat)
•Mostlysaltwater•Hydrafoundinfreshwater
•Howbigarethey?(Size)•Canbeupto6.5feetindiameterandhave~100footlongtentacles
PhylumCnidaria(Cont.)•Whatdotheyeat?Howdotheyeat?
• Tentaclescapturesmallanimals.•Nematocystsinjectpoison.• Tentaclespushfoodintomouth
•Howdotheymove?•Nervenetcoordinatescontractionofspecializedcellsmobile,movebycontractionandexpansionofbody
Digestion•Capturepreyusingstingingcellstoinjectvenom- paralyzesprey
•Pullpreyintomouth,digestinbodycavitydigestivesystem:1opening- expelfoodfrommouthsalso.
PhylumCnidaria(Cont.)•Howdotheybreath?Dotheybreath?
• Thethinbodyishighlyadaptedtogasexchangeinthewater(=highsurfacearea)
• Thussimplediffusionissufficienttoacquireoxygenandremovecarbondioxide
PhylumCnidaria(Cont.)•Howdotheyreproduce?
• Asexually• Budding&Regeneration
• Sexually• Adultmedusa releasessperm andeggs intothewaterwhereexternalfertilizationtakesplaceà zygote
• Zygoteformstheblastula (hollowballofcells)andthenformsaplanula (ciliatedlarva)
• Polyp attachestotheoceanflooranddevelopsmouthandtentacles
• Stacksofmedusae formandthendetachtoformindividualjellyfish
Section21.3 Figure21.11
CnidariansLifeCycle
Cnidariansreproducesexuallyandasexually.
CnidarianClassification
• Class- Hydrozoa– Ex.HydraandPortugueseManofWar
• Class- Scyphozoa– Ex.Jellyfish
• Class- Anthozoa– Ex.CoralandSeaAnemones
Class:Hydrozoa• Hydra
• Polypformfoundinpondsandlakes
• PortugeseMan-of-War• Foundintropicaloceans• Verypoisonoustofishandevenhumans
Image Source: http://animals.nationalgeographic.com/staticfiles/NGS/Shared/StaticFiles/animals/images/primary/portuguese-man-o-war.jpgHydra Image Source: http://www.microscope-microscope.org/gallery/Mark-Simmons/images/hydra2.jpg
• Over200species
• Commonjellyfishexistasbothpolypsandmedusae
Class:Scyphozoa
Image Source: http://www.dnr.sc.gov/marine/pub/seascience/jellyfi.html#life
• Includescoralsandseaanemones• Allmarine• Medusastagecompletelyabsent
•Corals• Arepolypsthatliveinsmallcolonies• Usenutrientsfromalgaeforenergy• GreatBarrierReef
• Largestcoralcolonyonearth
• SeaAnemones• Arepolypsthatusepoisonoustentaclestofeedonsmallfish
Class:Anthozoa
CoralPolypsCoral Eating go to about 3:20
https://youtu.be/NuCt0-m3VI8
CoralReef
SeaAnemone
Image Source: http://www.pbs.org/kcet/shapeoflife/animals/cnidaria8.html