1. Cnidarians Hydrozoa – Hydras Scyphozoa – Sea Jellies , “ Jelly fish”
Anthozoa- Sea Anemones

2. Cnidarians Cnida- “nettle” Diploboastic – Radial Symmetry
Gastrodermis & Epidermis
Radial Symmetry
Cnidocytes- Nematocysts
Polyp – Medusa
Incomplete digestive tract
Simple Nervous net, contractile cells

3. Polyp Medusa
Oral
Aboral
Oral
Aboral

4. Cnidarian Body Forms

5. Cnidarian Cnidocytes

6. Cnidocyte trigger

7. Symmetry

8. Hydra nutrition

9. Cnidarian circulation

10. Simple Nervous net

11. Hydra sp.

12. Epidermis

15. Cross section

16. Nematocysts

17. Female Male

18. Obelia

19. Hydranth
Gonangium
Medusa
Buds
Ceonosarc
Gonotheca
Perisarc

20. Perisarc
Hypostome
Hydrotheca
Ceonosarc

21. Obelia sp. life cycle

24. Obelia sp. medusae

26. Protective pantyhose worn by north Queensland life savers

27. Near fatal sting by C. fleckeri on a 13 year old boy at Cairns, Australia

28. Cnidarian Body Forms

29. Cnidarian Cnidocyts

30. Hydra w.m.

31. Hydra

32. Class Scyphozoa
Example
Aurelia (Moon Jelly)

33. Planula of Aurelia

34. Aurelia Scyphistoma - & strobilus

35. Aurelia sp. ephrya

36. Ephyra anatomy

37. Aurelia sp.

41. 2 3 4 1 5 6

42. 1 2 3 4 5 6 7 8

43. Medusa anatomy

44. Aurelia Anatomy

45. Class Anthozoa no medusa stage
Examples
Sea Anemones: Metridium sp.
Corals (hard and soft)

46. Sea Anemones

47. Metridium External Anatomy

49. Metridium c.s.

50. Metridium c.s.

51. Enlargement of Pharynx
1. Siphonoglyph
2. Retractor muscle
3. Primary septum
4. Pharynx
5. Gastrovascular Cavity

52. 1 2 11 3 10 4 9 5 6 7 8

53. Close-Up of Septa 1. Primary septum 2. Secondary septum
3. Tertiary septum
4. Retractor muscle
5. Septal filament
6. Gastrovascular cavity

54. Close-Up of Body Wall 1. Epidermis 2. Mesoglea 3. Gastrodermis
4. Septal filament
5. Primary septum
6. Secondary septum

55. Phylum Ctenophora
Comb jellies possess rows of ciliary plates and adhesive colloblasts
Comb jellies use retractable tentacles to capture food.

56. PHYLUM CTENOPHORA
Characteristics
Comb plates
Colloblasts (glue cells)

57. Pleurobrachia

58. Ctenophorans