1. Phyla Cnidaria and Ctenophora
Radial or biradial symmetry

2. Contents Phylum Cnidaria Phylum Ctenophora Unique characteristics
Systems
1 (Integumentary, skeletal, muscle and digestive)
2 (Excretory, respiratory, circulatory and nervous)
3 (Endocrine and reproductive)
Taxonomy
Phylum Ctenophora
Comparison to Cnidaria

3. Phylum Cnidaria Some unique characteristics Nematocysts
Alternation of generations
(polyp and medusa body forms)
Planula larva
Mesoglea

4. Cnidaria Systems 1 Integumentary Skeletal Muscle Digestive
One cell layer (epidermis)
Skeletal
Hydrostatic or some with endoskeletons and/or exoskeleton of calcium carbonate (Anthozoa)
Muscle
None; epith-muscle cells (fibers from cells into mesoglea) Anthozoa may have muscles
Digestive
Incomplete

5. Cnidaria Systems 2 Excretory Respiratory Circulatory Nervous
Isotonic in marine; some freshwater forms use contractile vacuoles)
Respiratory
No system , use cellular diffusion
Circulatory
No system, use cellular diffusion and mesoglea
Nervous
Nerve net (ring around the bell of medusa)

6. Cnidaria Systems 3 Endocrine Reproductive
Have hormones, secreted by nervous system
Reproductive
Alternation of generations, vary as to dominant stage
Medusa is the sexual body plan
Polyp is the asexual body plan
Planula larva
Dioecious or monoecious

7. Cnidaria Taxonomy Class Hydrozoa (hi-dro-zo-ah)
Hydra,
Obelia,
Gonionemus,
Physalia
Class Scyphozoa (sky-fo-zo-ah)
Aurelia
Class Anthozoa (an-tho-zo-ah)
Metridium
Tubipora
Gorgonia
Other anthozoan coral
Class Cubozoa (ku-bo-zo-ah)
No specimens

8. Class Hydrozoa
Alternation of generation with polyp as the dominant body plan
Incomplete digestive with an unbranched gut.
Mesoglea thin
Medusa with a velum

9. Class Hydrozoa Genus— Hydra
CS through hydra

10. Class Hydrozoa Genus— Obelia

11. Class Hydrozoa Genus— Gonionemus

12. Class Hydrozoa Genus— Physalia

13. Class Scyphozoa
Alternation of generation with medusa the dominant body plan
Incomplete digestive with four branches
Mesoglea thick with some cells
Medusa without velum

14. Class Scyphozoa Genus— Aurelia

15. Class Anthozoa No alternation of generation - polyps only
Incomplete digestive with 6 to 8 branches (septia)
Nematocyst in the gut (acontia)
Mesoglea thick and with muscle tissue
Coral Reefs

16. Class Anthozoa Genus — Metridium

17. Class Anthozoa Genus — Tubipora

18. Class Anthozoa Genus — Gorgonia
Sea fan
String coral

19. Other Anthozoan Coral Astrangia Fungia Brain coral Sea pansy
Lettuce coral

20. Coral Reefs Fringing reef Barrier reef Atolls
Close to land mass none or a narrow lagoon between land and shore.
Barrier reef
Has a wide and deep lagoon between reef and shore line.
Atolls
Reefs that encircle a lagoon, but there is no island

21. Phylum Ctenophora Unique Characteristics Comb plates Medusa only
Luminescence common
Position of paired tentacles changes symmetry to biradial

22. Comparison Ctenophora to Ctenophora
Differences
No alternation of generations (medusa only)
No nematocysts
Biradial symmetry, two tentacles
Combs
Complete digestive system
May be triploblastin
Similarities
Aboral-oral axis
Nerve net
Lack of organ systems

23. Taxonomy Phylum Ctenophora
Class Tentaculata (ten-tack-u-la-ta)
Pleurobrachia

24. End of presentation