1. Section 2 Cnidaria and Ctenophora
Chapter 33
Section 2
Cnidaria and Ctenophora

2. Phylum Cnidaria Body Plan
Freshwater hydra, stinging jellyfish, & flowerlike coral
Medusa- bell-shaped
Polyp- vase-shaped

4. Cnidaria- Body Plan Epidermis- outer layer Gastrodermis- inner layer
Mesoglea- between epidermis & gastrodermis
Gastrovascular cavity- single opening or mouth
Tentacles- flexible extensions

6. Cnidaria- Feeding/Defense
Cnidocytes- specialized cells used for defense and capturing prey
Nematocyst- cnidocyte organelle, long filament coiled up

8. Cnidaria- Nervous System
Nerve net- diffuse web of interconnected nerve cells

9. Cnidaria Classes
Class Hydrozoa
Portuguese man-of war
Hydra

10. Cnidaria Classes
Class Cubozoa
Box jellyfish

11. Cnidaria Classes
Class Scyphozoa
Jellyfish

13. Cnidaria Classes
Class Anthozoa
Sea anemones & corals

14. Phylum Ctenophora “Comb-like”/ Comb jellies
Move by beating their cilia
Have cells called colloblasts, which secrete a sticky substance that binds to their prey- located on two tentacles

16. Phylum Ctenophora
Sensory structure- apical organ- ables ctenophores to sense their orientation in water
Bioluminescence- production of light by means of a chemical reaction

18. REVIEW!!! Describe how cnidarians feed.
Name one organism from each of the 4 cnidarian classes.
Compare and contrast cnidarians and ctenophores.