Phylum Cnidaria

1
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

Lions mane eats another jelly
16
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
Lions 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

1. No cephalization or nervous system
2. 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
Lions mane
60
Jellyfish
Purple lions 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
67
(No Transcript)
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 fleckerithe Box jelly fish