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1. 1 Cnidarians & Ctenophorans copyright cmassengale
2. 2 copyright cmassengale
3. 3 Phylum Cnidaria About 9000 species
Most are marine (jellyfish, coral, sea anemones, Portuguese man-of war)
Hydras are found in freshwater
All have arm-like tentacles
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4. 4 Cnidarian Characteristics Radial symmetry
Hollow gut -Gastrovascular cavity has single opening (serves as both mouth and anus)
Two tissue layers (diploblastic)
Outer epidermis and inner gastrodermis copyright cmassengale
5. 5 Cnidarian Characteristics Either tubular or bell shaped
Tentacles surround mouth
Only animal with cnidocytes (stinging cells) found in the tentacles
Nematocyst – coiled, harpoon-like stinger inside cnidocyte that shoots out copyright cmassengale
6. 6 Cnidarian Characteristics Cnidocytes contain poison to paralyze prey
Tentacles bring food into mouth
Inner gastrodermis secretes digestive juices into gastrovascular cavity which digests food and circulates nutrients
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7. 7 Extracellular Digestion copyright cmassengale
8. 8 Cnidocyte copyright cmassengale
9. 9 Nematocyst copyright cmassengale
10. 10 copyright cmassengale
11. 11 Cnidarian Systems Have a simple nerve net & sensory receptors
Muscles help in directional movement & capturing prey
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12. 12 copyright cmassengale
13. 13 Two Main Body Plans of Cnidarians copyright cmassengale
14. 14 copyright cmassengale
15. 15 Cnidarian Diversity Scyphozoans:
Jellyfish
Anthozoans:
Sea anemones
Corals
Hydrozoans:
Hydra
Cubozoa
Box Jellies copyright cmassengale
16. 16 Cnidarian Diversity copyright cmassengale
17. 17 copyright cmassengale
18. 18 Anthozoan Characteristics Sea Anemones
Brightly colored & Resemble flowers
Solitary polyps
Feed on invertebrates & fish
Corals
Most are colonial
Build limestone case
Live as polyps in their case copyright cmassengale
19. 19 Sea Anemones & Coral Exist only as Polyps
Clownfish live in anemone tentacles
Corals build a limestone case which build up & form reefs copyright cmassengale
20. 20 Distribution of Coral Reefs copyright cmassengale
21. 21 copyright cmassengale
22. 22 Hydrozoans Hydra
Exist only as polyps
Reproduce by budding
Freshwater only
Form resistant zygotes when environment is bad
Move by somersaulting with tentacles copyright cmassengale
23. 23 copyright cmassengale
24. 24 copyright cmassengale
25. 25 copyright cmassengale
26. 26 Colonial Hydrozoan (not a single organism
Tentacles sting prey such as fish & humans
Polyps in colony feed
Has gas-filled air float copyright cmassengale
27. 27 copyright cmassengale
28. 28 Hydrozoan Life Cycle Most hydrozoans alternate polyp and medusa forms, as in the life cycle of Obelia copyright cmassengale
29. 29 Obelia Life Cycle (Hydrozoan)Larva called a planula copyright cmassengale
30. 30 Cubozoans copyright cmassengale
31. 31 copyright cmassengale
32. Scyphozoan Characteristics Jellyfish
Medusa is dominant body form
Go through small polyp stage during life cycle
Stinging tentacles
May live close to shore or the open ocean
37. 37 copyright cmassengale
38. 38 Ctenophoran Characteristics Called comb jellies
All marine
Approximately 100 species
May be spherical, ovoid, or elongate in appearance
Bioluminescent copyright cmassengale
39. 39 Ctenophoran Characteristics Radial symmetry
Have eight plates of fused cilia that resemble combs
Move by beating cilia
Most of the body is jelly-like mesoglea
Body & tentacles covered with sticky mucus to catch prey copyright cmassengale
40. 40 copyright cmassengale
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