1 unit 4.2 phylum cnidaria. 2 phylum cnidaria radial symmetry mouth at oral end surrounded by...
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*Phylum CnidariaRadial symmetryMouth at oral end surrounded by tentacles. One opening into and out of gastrovascular cavity.Cnidocytes that discharge nematocystsTwo body formsPolypMedusaTwo germ layersNerve netStill no circulatory or respiratory systems
*Mouth and Tentacles
*Generalized Cnidarian Life CycleCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
*Cnidocyte Structure and Nematocyst DischargeCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
*Diploblastic - 2 germ layers
Epidermis - outer covering (ectoderm)Mesoglea - middle non-living jelly-like layerGastrodermis - lines gastrovascular cavity (endoderm)
*Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.Cnidarian Body Wall
*Class HydrozoaFreshwater & marine.Cnidocytes present only on epidermis.Medusa (if present) with a muscular velum that aids in propulsion.Asexual reproduction by budding.Sexual reproduction via gametes produced by epidermis & released into water.Hydra, Ctenophores, Obelia, Man-of-War
*Class HydrozoaHydraSpermariesOvariesEncapsulatedembryoSexual cycleAsexual cycleBudding
ObeliaFreshwater or marine.Live in colonies rather than free living like hydra.Colonies contain two types of polyps, feeding and reproductive. Dual stage life cycle like other Cnidarians.*
*Class Hydrozoa Gonionemus
Class HydrozoaPhysaliaCommonly called the Portuguese Man-of-War.Not a jellyfish or even a single organism. Made of a colony of hydrozoans that perform specialized functions.*
Class HydrozoaPhysaliaGastrozooids Feeding & digestion.Dactylozooids Prey capture.Gonozooids Reproduction.Pneumatophore Gas-filled float. *
True JellyfishTentacles up to 70 meters in lengthCnidocytes present in gastrodermis & epidermisThick mesoglea contains amoeboid cellsGametes produced by gastrodermisAll marine
*Class ScyphozoaAurelia Moon Jellies
*Aurelia Life HistoryCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
*Class CubozoaMedusa dominant & cuboid Tentacles arise at four corners from blade-like pendalium.All marineStrong swimmers which prey primarily on fishStings of some may be fatal within minutes to humans.
*Class CubozoaThe Box Jellyfish
Class CubozoaThe Box JellyfishThe most venomous poison known to man.One brush against the skin will inject enough venom to put a full grown adult in the hospital for over a week.Even a full morphine drip can not relieve the pain. *
Class CubozoaThe Box Jellyfish*
Class CubozoaThe Box Jellyfish*
*Class AnthozoaSea Anemones & CoralMedusa stage virtually absentSolitary or colonialSome produce protective skeletonsCnidocytes on tentacles and lining the gastrovascular cavityMesoglea contains amoeboid cells like all other CnidariansAll Marine
*Class AnthozoaSea Anemone
*Class AnthozoaMetridiumMouthTentaclesPharynxSeptumGastrovascular cavity
*Class AnthozoaCoralsProtective skeleton of calcium carbonatePolyp retracts when not feeding
*ZooxanthellaePhotosynthetic dinoflagellates (brown)Live in coralsProvide nutrients for coral by photosynthesis while gaining a homeMutualism
*CoralsColony of interconnected polyps
*Class AnthozoaMeandrinaBrain Coral
*Class AnthozoaGorgoniaSea Fan
*Class AnthozoaTubiporaPipe Organ Coral
*Class AnthozoaActinodiscusMushroom Coral
Class AnthozoaAcroporaStaghorn Coral*
*Coral ReefsFormed over thousands of years from successive layers of coral skeleton deposits (calcium carbonate forms underwater mountains of coral animal skeletons)The underwater equivalent of the Amazon jungle- very high species diversity and biomassReefs contain sponges, colonial hydrozoans, anemones, many varieties of coral, fish, many types of worms weve not discussed, not to mention bryozoans, ctenophores, protists, bacteria, etc etc..
*Coral Reef EcosystemCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.Photo McGraw-Hill Higher Education, Barry Barker, Photographer
*AnthozoaScyphozoaCubozoaHydrozoaCladogram of Cnidaria
**Fig. 13.2***Fig. 13.12b*Fig. 13.18**