1. Hydra, Jellyfish, Coral, & Sea Anemones
Cnidaria
Hydra, Jellyfish, Coral, & Sea Anemones

2. Phylum Cnidaria Some examples of Cnidaria are:
Sea anemones and Corals- Anthozoa
Hydra- Hydrozoa
Jelly fish- Scyphozoa
Ctenophores- non stinging Cnidarians:
Comb Jelly

3. Anatomy A. Polymorphism- Cnidarians have more than one body form:
1. Polyp
2. Medusa

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

5. Polyp (sea anemone)

6. Polyp (Hydra)

7. Medusa Form Umbrella shape Tentacles around mouth
Motile, Free-swimming

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

9. Level of Organization A. Cnidarians have tissues B. No organs
C. Most Cnidarians have Radial Symmetry

10. Radial Symmetry
Radial
Compass jellyfish

11. Habitat
Aquatic:
1. Most Marine
2. Few fresh-water

12. Feeding A. Carnivores (predators) Lion’s mane eats another jelly
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

13. 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)

14. Lion’s mane jellyfish eating

15. Respiration
Via diffusion
Body is two cell layers
thick

16. Internal Transport
Via diffusion

17. Excretion
Via diffusion

18. Response
No nervous system
Nerve net around mouth

19. Locomotion Medusa- motile, free-swimming
Polyps- sessile, attached to hard substrate
Exceptions:
1. Hydra tumbles on tentacles
2. Sea anemones glide on pedal disc

20. Reproduction 1. Asexual budding 2. Sexual
a. Medusae release sperm & eggs
b. Larvae are free-swimming

21. 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

22. Class Anthozoa: Sea Anemones

23. Sea Anemones (with sea urchins)

24. Sea Anemones Clown fish with sea anemone

25. Clown fish & eggs with sea anemone

26. Clown fish with sea anemone

27. Giant Sea Anemone

28. Rosy Sea Anemone

29. Class Anthozoa: Corals

30. Brain Coral

31. Coral

32. Colt Coral

33. Elkhorn Coral

34. Cabbage Coral

35. Flower Coral

36. Feather Coral

37. Gorgonian Fan Coral

38. Lamellina Coral

39. Sun Coral

40. Subergorgia Coral

41. Soft Coral

42. Sea Pen

43. Sea Fan

44. Sea Plume

45. Class Hydrozoa: Green Hydra

46. Hydra

47. Brown Hydra with buds

48. Brown Hydra eating

49. Hydra eating Daphnia
Hydra eats Daphnia

50. Class Scyphozoa: True Jellyfish
Fried egg jelly

51. Jellyfish

52. Jellyfish
Red-eyed medusa

53. Jellyfish

54. Jellyfish

55. Jellyfish
Lion’s mane

56. Jellyfish
Purple lion’s mane

57. Upside down Jelly fish

58. Upside down Jelly fish

59. Sea Nettle

60. Jelly and diver

61. Giant Jelly off Coast of Japan

62. Beached Jelly fish

64. Jelly fish Humor

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

66. Portuguese Man 0’ War
Tentacles of Physalia physalis

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

68. Class Cubozoa: Box Jellyfish

69. Chironex fleckeri the Box jelly fish