1. Phylum Cnidaria

2. Radially symmetricRadially symmetric DimorphicDimorphic CnidocytesCnidocytes ~10,000 species~10,000 species AquaticAquatic

3. Taxonomic Characteristics DiploblasticDiploblastic –Epiderm & hypoderm –Tissues

4. Taxonomic Characteristics DiploblasticDiploblastic Incomplete digestive tractIncomplete digestive tract –coelenteron

5. Taxonomic Characteristics DiploblasticDiploblastic Incomplete digestive tractIncomplete digestive tract Decentralized nervous systemDecentralized nervous system

6. Taxonomic Characteristics DiploblasticDiploblastic Incomplete digestive tractIncomplete digestive tract Decentralized nervous systemDecentralized nervous system CnidocytesCnidocytes

7. Everted nematocyst firing nematocystfiring nematocystfiring nematocystfiring nematocyst

8. Hydrazoan stinging and capturing prey

9. Cnidarian Dimorphism

10. Cnidarian Dimorphic Life Cycle Colonial hydrozoan

11. Cnidarian Taxonomy Phylum CnidariaPhylum Cnidaria –Class Hydrozoa –Class Scyphozoa –Class Cubozoa –Class Anthozoa

12. Phylogeny of Cnidaria Cladogram based on molecular systematic data

13. Class Hydrozoa Most varied and derived of the cnidarian groupsMost varied and derived of the cnidarian groups Includes freshwater species (hydra spp)Includes freshwater species (hydra spp) Colonial species commonColonial species common Most have typical dimorphic life cycleMost have typical dimorphic life cycle Examples of polyp-only forms (hydra)Examples of polyp-only forms (hydra) Examples of medusa-only formsExamples of medusa-only forms

14. Atypical Hydrozoans Hydra Hydra –Lacks medusa stage –Asexual - budding –Sexual - gametes

15. Atypical Hydrozoans Gonionemus – reduced polyp formGonionemus – reduced polyp form

16. Colonial Hydrozoans Colony of specialized hydranthsColony of specialized hydranths –Gonangia (gonozooids) – reproduction –Gastrozooids – feeding –Dactyolozooids – catching prey hydranths

17. Colonial Hydrozoans

18. Portuguese Man-O-War (Physalia physalis)Portuguese Man-O-War (Physalia physalis) Polyp – air bagPolyp – air bag Feeding & reproductive hydranths - tentaclesFeeding & reproductive hydranths - tentacles

19. Colonial Hydrozoans Fire CoralsFire Corals –NOT TRUE CORAL Hydrozoan colonyHydrozoan colony –TRUE CORAL Anthozoan colonyAnthozoan colony –Cnidocytes cause severe pain

20. Dimorphic Life Cycle and Reproductive Modes AsexualAsexual –Budding Medusa budsMedusa buds Polyp budsPolyp buds SexualSexual –Gonadal tissue –Gametes –Fertilization, embryogenesis –Planula larvae

21. Class Scyphozoa Typically thought of as jellyfishTypically thought of as jellyfish Most have typical dimorphic life cycleMost have typical dimorphic life cycle –Polyp stage is atypical –Majority of life cycle spent in medusa form

22. Scyphozoan Life Cycle

23. Aurelia aurita (Moon jelly)

24. CNIDARIA Class Scyphozoa Sea thimble jellyfish (Linuche unguiculata), HondurasSea thimble jellyfish (Linuche unguiculata), Honduras Tiny jellyfish (< 1 inch) that swarm in the springTiny jellyfish (< 1 inch) that swarm in the spring Adults and larvae (“sea lice”) may cause a severe skin reaction in humansAdults and larvae (“sea lice”) may cause a severe skin reaction in humans Photo Copyright © Diane R. Nelson

25. CNIDARIA Class Scyphozoa Upside down jellyfish (Cassiopea xamachana) from Bermuda, with zooxanthellaeUpside down jellyfish (Cassiopea xamachana) from Bermuda, with zooxanthellae This specimen is swimming up to the surface, where its reflection is visibleThis specimen is swimming up to the surface, where its reflection is visible Copyright ©The McGraw-Hill Companies, Inc. Permission required for reproduction or display Photo Copyright © Diane R. Nelson

26. CNIDARIA Class Scyphozoa Jellyfish (Mastigias sp., family Rhizostomeae) from Jellyfish Lake in Palau, western PacificJellyfish (Mastigias sp., family Rhizostomeae) from Jellyfish Lake in Palau, western Pacific Have lost their ability to sting and depend on zooxanthellae for nutritionHave lost their ability to sting and depend on zooxanthellae for nutrition Copyright ©The McGraw-Hill Companies, Inc. Permission required for reproduction or display Photo Copyright © Diane R. Nelson

27. CNIDARIA Class Scyphozoa Lion’s Mane Jelly (Cyanea capillata)Lion’s Mane Jelly (Cyanea capillata) Bell – 6 ftBell – 6 ft Tentacles – 120 ftTentacles – 120 ft

28. Lion’s Mane Jelly (Cyanea capillata)

29. http://www.youtube.com/watch?v=HqfCm 58SB6Yhttp://www.youtube.com/watch?v=HqfCm 58SB6Yhttp://www.youtube.com/watch?v=HqfCm 58SB6Yhttp://www.youtube.com/watch?v=HqfCm 58SB6Y

30. Class Cubozoa

31. Phylum Cnidaria Class Cubozoa Carybdeid, Darwin, AustraliaCarybdeid, Darwin, Australia

32. Phylum Cnidaria Class Cubozoa Carybdea sivickisiCarybdea sivickisi South pacificSouth pacific

33. Phylum Cnidaria Class Cubozoa Chironex fleckeriChironex fleckeri Size of human head with tentacles (4) up to 9 ft longSize of human head with tentacles (4) up to 9 ft long 18-24 ft of tentacles can deliver enough poison to kill in <5 min.18-24 ft of tentacles can deliver enough poison to kill in <5 min.

34. Class Anthozoa Anemones & CoralsAnemones & Corals Lack medusa formLack medusa form Form colonies (especially coral)Form colonies (especially coral)

35. Class Anthozoa – Typical Polyp Form

36. CNIDARIA Class Anthozoa giant anemone or purple-tipped anemone (Condylactis gigantea) often harbors cleaning shrimp among its tentaclesgiant anemone or purple-tipped anemone (Condylactis gigantea) often harbors cleaning shrimp among its tentacles Common in Bermuda and the CaribbeanCommon in Bermuda and the Caribbean Photo Copyright © Diane R. Nelson

37. Anemone with Anemone Fish

39. Anthozoan Motility

41. Class Anthozoa – Hard Coral Hexacorallia – 6-fold symmetryHexacorallia – 6-fold symmetry Precipitate Ca 3 (CO 3 ) 2 from sea water to produce skeletal structures that become coral reefsPrecipitate Ca 3 (CO 3 ) 2 from sea water to produce skeletal structures that become coral reefs Contain zooxanthellaContain zooxanthella

42. Class Anthozoa – soft corals Octocorallia – 8-fold symmetryOctocorallia – 8-fold symmetry Form complex tube- like skeletal structuresForm complex tube- like skeletal structures Lack zooxanthellaLack zooxanthella

43. Phylum Cnidaria Class Anthozoa Subclass OctocoralliaSubclass Octocorallia –Soft coral

44. Class Anthozoa – Soft Corals

45. Soft Corals – Class Anthozoa

46. Reefs Shallow tropical watersShallow tropical waters Hermatypic corals (Class Anthozoa, subclass hexacorallia, order scleractinia)Hermatypic corals (Class Anthozoa, subclass hexacorallia, order scleractinia) Contain symbiotic dinoflagellatesContain symbiotic dinoflagellates Precipitate CaCO 3 to form “exoskeleton”Precipitate CaCO 3 to form “exoskeleton”

47. Zooanthella Green algaeGreen algae

48. Atoll

49. Phylum Ctenophora Comb-jelliesComb-jellies –Rows of cells with fused cilia – comb-plates <100 species<100 species Lack cnidocytesLack cnidocytes Complete digestive tractComplete digestive tract

50. Ctenophore Morphology

53. Ctenophore Body Forms Biradial symmetryBiradial symmetry –Two tentacle clusters –Even # comb rows\ Some are bilateralSome are bilateral

56. Reef MovieReef MovieReef MovieReef Movie Bioluminescent MovieBioluminescent MovieBioluminescent MovieBioluminescent Movie Ctenophore MovieCtenophore MovieCtenophore MovieCtenophore Movie http://www.montereybayaquarium.org/efc /efc_se/se_jellies_rhythm.asphttp://www.montereybayaquarium.org/efc /efc_se/se_jellies_rhythm.asphttp://www.montereybayaquarium.org/efc /efc_se/se_jellies_rhythm.asphttp://www.montereybayaquarium.org/efc /efc_se/se_jellies_rhythm.asp