1. WARM UP
Draw a picture of a sponge, showing the ostia, osculum, and collar cells.

2. Cnidarians Notes
Phylum Cnidaria

3. General Characteristics
9,000 aquatic species 
Stinging cells
Radial symmetry

4. Structure Inner layer Outer layer Digestive cavity Single opening
Nematocysts in tentacles
Radial symmetry

5. Structure Body Forms Polyp Medusa Sessile, tube shaped
Free-swimming “umbrella”

6. Feeding Nerve net detects impulses
Sting and bring in prey
All digestion in gastrovascular cavity

7. Reproduction
Asexual
Budding
Sexual
External fertilization

8. Classification
Class Scyphozoa
Jellyfish
Medusa dominant

9. Classification
Class Anthozoa
Corals and anemones
Polyp dominant

10. Classification
Class Hydrozoa
Portuguese man o’ war
Colonies

11. WRAP UP
Classify each of the following pictures into the appropriate Class of cnidarians.