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