1. Hydra, jellyfish, coral, & sea anemones
Phylum Cnidaria
Hydra, jellyfish, coral, & sea anemones

2. Phylum Cnidaria Examples? Sea anemones Corals Sea Pen Sea Fan
Sea Plume
Hydra
Jelly fish
Portuguese Man o’ War
Box Jelly Fish

3. I. Body Structure A. Polymorphism = more than one body form 1. Polyp
2. Medusa

4. B. Polyp
Tube with tentacles
around the mouth
Sessile
Coral polyp

5. Polyp (sea anemone)

6. Mythical Hydra

7. Polyp (Hydra)

8. Perseus slays the Gorgon Medusa

9. C. Medusa
Umbrella shape
Tentacles around mouth
Motile, Free-swimming

10. D. Tentacles Have nematocysts (stinging cells)
Coiled thread discharges
like a harpoon
Contains neurotoxin
Paralyzes prey
Discharged nematocyst

11. Discharged nematocyst

12. II. Level of Organization
A. Tissue
B. No organs

13. III. Symmetry
Radial
Compass jellyfish

14. IV. Habitat
A. Aquatic
1. Most Marine
2. Few fresh-water

15. V. Feeding A. Carnivores (predators) B. Process of feeding
1. Tentacles sting prey with
nematocysts
2. Tentacles grab prey
3. Prey pulled into mouth
Lion’s mane eats another jelly

16. 4. Prey stuffed into gastro-vascular cavity (GVC)*
Process of feeding
4. Prey stuffed into gastro-vascular cavity (GVC)*
5. GVC makes enzymes, extra-cellular digestion
6. Undigested food back out mouth
*incomplete digestive tract (no anus)

17. Lion’s mane jellyfish eating

18. VI. Respiration
Via diffusion
Body is two cell layers
thick

19. VII. Internal Transport
Via diffusion

20. VIII. Excretion
Via diffusion

21. IX. Response
No cephalization or nervous system
Nerve net around mouth

22. IX. Response C. Sensory cells 1. Chemoreceptors (chemicals)
2. Thigmoreceptors (touch)
3. Photoreceptors (light)
Ocelli (eyespots)
4. Statocysts (balance)

23. X. Locomotion Medusa motile, free-swimming Polyps sessile Exceptions:
1. Hydra tumbles on tentacles
2. Sea anemones glide on pedal disc

24. XI. Reproduction 1. Asexual budding from polyps or medusae 2. Sexual
a. Medusae release sperm & eggs
b. Some monoecious, some dioecious
c. Larvae free-swimming

25. XII. Ecological Role Predators and prey
Neurotoxins in medical research
Coral – jewelry, building, reefs (surfing!)
Coral reefs - habitat for many
-great biodiversity
- protect coastline
E. Symbiosis with other organisms

26. Class Anthozoa: Sea Anemones

27. Sea Anemones (with sea urchins)

28. Sea Anemones Clown fish with sea anemone

29. Clown fish & eggs with sea anemone

30. Clown fish with sea anemone

31. Giant Sea Anemone

32. Rosy Sea Anemone

33. Class Anthozoa: Corals

34. Brain Coral

35. Coral

36. Colt Coral

37. Elkhorn Coral

38. Cabbage Coral

39. Flower Coral

40. Feather Coral

41. Gorgonian Fan Coral

42. Lamellina Coral

43. Sun Coral

44. Subergorgia Coral

45. Soft Coral

46. Sea Pen

47. Sea Fan

48. Sea Plume

49. Class Hydrozoa: Green Hydra

50. Hydra

51. Brown Hydra with buds

52. Brown Hydra eating

53. Hydra eating Daphnia
Hydra eats Daphnia

54. Class Scyphozoa: True Jellyfish
Fried egg jelly

55. Jellyfish

56. Jellyfish
Red-eyed medusa

57. Jellyfish

58. Jellyfish

59. Jellyfish
Lion’s mane

60. Jellyfish
Purple lion’s mane

61. Upside down Jelly fish

62. Upside down Jelly fish

63. Sea Nettle

64. Jelly and diver

65. Giant Jelly off Coast of Japan

66. Beached Jelly fish

68. Jelly fish Humor

69. Portuguese Man 0’ War (a Hydrozoan), NOT a true jelly fish

70. Portuguese Man 0’ War
Tentacles of Physalia physalis

71. Portuguese Man o’ War vs. Box Jelly fish

72. Class Cubozoa: Box Jellyfish

73. Chironex fleckeri the Box jelly fish