1. Sea Anemones, Jellyfish, & Corals
Phylum Cnidaria
Sea Anemones, Jellyfish, & Corals

3. I) Cnidarians Phylum Cnidaria True Tissues Radial Symmetry
Means “to have stingers”
True Tissues
Radial Symmetry
Radial Nerve Net
Partial Digestive Tract
Only have one opening
Some 10,000 species known
First appeared some Million Years Ago

4. II) Morphology Oral surface Aboral Surface
1) Where the mouth is
Aboral Surface
1) Opposite side of the mouth
Central mouth / anus surrounded by tentacles
Mouth opens to gut

5. II) Morphology
Nematocysts
Cnidae
Unique stinging structure

6. II) Morphology Polyp Medusa
Sac-like attached stage with mouth & tentacles orientated upwards
Medusa
Jellyfish, an upside down polyp for swimming
Some cnidarians go through both life stages, others only one

7. II) Morphology Epidermis Gastrodermis Mesoglea External cell layer
Lines the gut
Mesoglea
1) Middle, gelatinous layer

8. III) Feeding Practically all are carnivores
Use nematocysts primarily to capture prey
Some contain toxins
Ingest into mouth
Extracellular digestion
1) Initial digestion that takes place outside the cells (in the gut)
Intracellular digestion
1) Final digestion within cells lining the gut

9. IV) Reproduction

11. V) Classes of Cnidarians
Hydrozoans
Leathery or bushy colonies of polyps
Siphonphores: drifting colonies of polyps
Scyphozoans
Jellyfish
Larger, bell-shaped medusas
Cubozoans
Anthozoans
Sea Anemones
Corals

12. A) Hydrozoans

14. B) Scyphozoans

15. C) Cubozoans

16. D) Anthozoans

17. D) Anthozoans