100%(1)1 out of 1 people found this document helpful
This preview shows page 48 - 52 out of 140 pages.
Outer covering – perisarc – non-livingChitinous – impregnated form chitin (structural sugar) ProtectiveChitin – similar to keratin which is a protein that grows hair and nails oCups at high end have polyps and feedoUnderneath have medusa – sexual phase oZooids – individual polyp organisms Feeding – hydranths Tubular, bottle shaped, vase-likeAll have terminal mouth All have tentacle encircling mouth Perisarc extends to cover and protect zooidCapture crustaceans, worms, larvae Obelia ReproductionoBuddingIncreases size of colony Feeding polyp budsMedusa buds – from ganangium (reproductive bud)Young medusaFree swimming Leave colony MatureProduce gametesMay fertilize colonyIf forms zygote will settle somewhereThrough asexual reproduction, new colony forms PhysaliaoPortuguese man-of-waroColony of floating medusa and polypsoLong tentacles
oGas-filled-sac – float oDangerous nematocysts oPurple tentacles – where all members of colony exist °Class – ScyphozoaLarger jellyfish“Cup” shaped animalsAs large as 2 meters in diameterTentacles can be 70cm longMost marineMost free-floating, free-swimming Some SeissileAdults tend to be medusasSchyphozoaoThick mesoglea – buoyantoVariationin presence and size of tentaclesoMargin of bell scallopedoEach incident has sense organ – rhopaliumEquilibrium Tactile senseSome have light sensitivity oOrients scyphoza oMouth on subumbrella side oAt end of projection called manubriumManubrium has four oral armsOral arms used to capture prey oGastric pouches – aid with digestion and subdue prey; also turn into gonads later on Four Extend to gastric filamentsFilaments have nematocysts to subdue preyNot considered organs because they are too simple
Scyphozoa – ReproductionoDiociusoGonads in gastric pouches of femaleoSperm released into wateroCarried by cilia to gastric pouch of femaleoZygote develops in open water or in folds of oral armsoCiliated larvaoBecomes polyp form – attachesoForms saucer-like buds – strobila oEach strobila breaks off and becomes new jellyfishAureliaoShort tentaclesoEats planktonoHas food pockets on bell marginoFood brought to mouth via ciliaoWaste expulsion and water flow through gastrovascular cavity by cilia Class – CubozoaoMedusa form is dominant oPolup is mostly unknown o“squarish” oTentacles at each corner of square oNot scalloped oEdge turns inward – velarium – increases swimming efficiency oFeeds on fish oFatal to humansoMost of life cycle unknown Class Anthozoao“flower animals” oNo medusa stageoAll marine
oDeep or shallow wateroPolar or tropical wateroSolitary or colonial oMuch size variation o100% polypsoMore advanced structuresoDon’t have to be be free swimming ever; heavier; more muscular; more complex feeding system oSea anemones, coralsoSubclassesZoanthatriaSea anemonesHard coralsCeriantipathariaTube anemones Thorny coralsAlcyonariaSoft corals