1. The Characteristics of Phylum Cnidaria

2. Characteristics of Phylum Cnidaria • radial symmetry • blind sac gut (= coelenteron or gastrovascular cavity) • diploblastic with mesoglea • polyp and medusa body forms • nematocysts (= specialized stinging capsules) • nerve net • lack excretory, circulatory & respiratory systems • complex life cycle • many colonial forms exhibiting polymorphism

3. oral Radial Symmetry aboral

4. Radial Symmetry JellyfishPhylum Cnidaria

5. Characteristics of Phylum Cnidaria radial symmetry blind sac gut (= coelenteron or gastrovascular cavity) diploblastic with mesoglea polyp and medusa body forms nematocysts (= specialized stinging capsules) nerve net lack excretory, circulatory & respiratory systems complex life cycle many colonial forms exhibiting polymorphism

6. Blind Sac Gut

7. Characteristics of Phylum Cnidaria radial symmetry blind sac gut (= coelenteron or gastrovascular cavity) diploblastic with mesoglea polyp and medusa body forms nematocysts (= specialized stinging capsules) nerve net lack excretory, circulatory & respiratory systems complex life cycle many colonial forms exhibiting polymorphism

8. Diploblastic- two germ layers Phylum Cnidaria

9. Characteristics of Phylum Cnidaria radial symmetry blind sac gut (= coelenteron or gastrovascular cavity) diploblastic with mesoglea polyp and medusa body forms nematocysts (= specialized stinging capsules) nerve net lack excretory, circulatory & respiratory systems complex life cycle many colonial forms exhibiting polymorphism

10. Nematocysts

11. Nematocyst Picture Nematocyst

12. More Nematocysts http://www.youtube.com/watch?NR=1&v=-Tp38DUjUnM&feature=endscreen

13. Characteristics of Phylum Cnidaria radial symmetry blind sac gut (= coelenteron or gastrovascular cavity) diploblastic with mesoglea polyp and medusa body forms nematocysts (= specialized stinging capsules) nerve net lack excretory, circulatory & respiratory systems complex life cycle many colonial forms exhibiting polymorphism

14. Nerve Net

15. Characteristics of Phylum Cnidaria radial symmetry blind sac gut (= coelenteron or gastrovascular cavity) diploblastic with mesoglea polyp and medusa body forms nematocysts (= specialized stinging capsules) nerve net lack excretory, circulatory & respiratory systems complex life cycle many colonial forms exhibiting polymorphism

16. Diffusion Across the Body Wall

17. Sea Anemones

18. Circulation in a Moon Jellyfish

19. Characteristics of Phylum Cnidaria radial symmetry blind sac gut (= coelenteron or gastrovascular cavity) diploblastic with mesoglea polyp and medusa body forms nematocysts (= specialized stinging capsules) nerve net lack excretory, circulatory & respiratory systems complex life cycle many colonial forms exhibiting polymorphism

20. The Cnidarian Life Cycle The Cnidarian Life Cycle

21. Characteristics of Phylum Cnidaria radial symmetry blind sac gut (= coelenteron or gastrovascular cavity) diploblastic with mesoglea polyp and medusa body forms nematocysts (= specialized stinging capsules) nerve net lack excretory, circulatory & respiratory systems complex life cycle many colonial forms exhibiting polymorphism

22. Coloniality and Polymorphism

23. Poly,orphism in the Portuguese Man- of-War

24. Coloniality CoralPhylum Cnidaria