1. Phylum Cnidaria

2. Phylum Cnidaria: Diagnostic Features
hydra, jellyfish, sea anemones, and corals
fresh water & marine
polymorphic (polyp & medusa forms)
benthic & planktonic
metazoans; tissue grade; diploblastic
radiate
predaceous

3. Cnidocytes- stinging cells with nematocysts

4. Histology
epidermis- epithelial muscle cells contain contractile fibers
gastrodermis- nutritive cells; flagellated; phagocytic
mesoglea- secreted, gelatinous layer between epidermis and the gastrodermis

5. Physiology nervous system: "nerve net"
respiration/excretion: diffusion/ammonia
reproduction: budding; sexual reproduction in medusae; planula larvae

6. Classification
Class Hydrozoa
Class Scyphozoa
Class Anthozoa

7. Class Hydrozoa (hydroids)
diversity species
Obelia, Gonionemus, and Hydra
Craspedacusta; found in Oklahoma; contains symbiotic algae
Physalia- Portuguese Man-O-War; colonial pelagic hydrozoan; pneumatophores

9. Portuguese Man-O-War

10. Siphonophore

11. Obelia: a colonial hydrozoan

12. Obelia colony

13. Craspedacusta

14. Class Scyphozoa (true jellyfish)
diversity spp.
most marine
example: Aurelia

15. Aurelia life cycle

17. Class Anthozoa (anemones & corals)
polyp form only
all marine
endosymbiotic algae

18. Coral Polyps

19. Sea Fan

20. Organ Pipe Coral

22. Sea Anemone

24. What is a coral reef? most diverse marine ecosystems on earth
200 million years in existence
growth ~ 1.3cm per year
calcium carbonate (CaCO3)
zooxanthellae (endosymbiotic algae)

25. Where are the coral reefs?
Coral reefs require clean, clear water that ranges in temperature from OC.

28. Why does the coral reef need protection?
visitors are destroying the reef
touching, standing, or anchoring
boat propellers
oil

30. Why does the coral reef need protection?
nutrient enrichment of coastal waters
septic tank leakage
wastewater outfall
shallow injection wells
fertilizers- nitrogen and phosphorus

31. Phylum Ctenophora
“Comb Jellies”