1. The Jellyfish Cnidarians have radial symmetry, a gastrovascular cavity, and cnidocytes All animals except sponges – Belong to the clade Eumetazoa, the animals with true tissues Phylum Cnidaria – Is one of the oldest groups in this clade

2. Cnidarians – Have diversified into a wide range of both sessile and floating forms including jellies, corals, and hydras – But still exhibit a relatively simple diploblastic, radial body plan

3. The basic body plan of a cnidarian – Is a sac with a central digestive compartment, the gastrovascular cavity – There are two types of body The polyp, a sessile attached form and Medusa, a free floating active form A single opening – Functions as both mouth and anus

4. http://webs.lander.edu/rsfox/invertebrates/hydra.html Anatomy of a polyp

5. Anatomy of a medusa http://webs.lander.edu/rsfox/invertebrates/aurelia.html

6. Cnidarians are carnivores – That use tentacles to capture prey The tentacles are armed with cnidocytes – Unique cells that function in defense and the capture of prey http://www.tarleton.edu/~biology/pfau/BIOL1214/lectures/2acoelomates/cnidarians.htm

7. A cnidocyte of a hydra Tentacle “Trigger” Nematocyst Coiled thread Discharge Of thread Cnidocyte Prey Campbell & Reece, Biology, 7th Ed., Pearson

8. Scyphozoans In the class Scyphozoa – Jellies (medusae) are the prevalent form of the life cycle In the class Cubozoa, which includes box jellies and sea wasps – The medusa is box-shaped and has complex eyes Class Anthozoa includes the corals and sea anemones – Which occur only as polyps

9. Physalia Hydrozoa

10. float tentacles Digestive polyps Reproductive polyps

11. Vellela vellela (By the Wind Sailor) http://www.flickr.com/photos/nativeagle/ 101348346/in/photostream/

12. Hydrozoa http://animaldiversity.ummz.umich.edu/site/accounts/pictures/Hydrozoa.html

13. Scyphozoans

15. Class - Cubozoa Box Jellies

16. Hydrozoans Most hydrozoans – Alternate between polyp and medusa forms http://orion1.paisley.ac.uk/courses/Tatner/biomedia/pictures/hydro.htm

17. An animal that eats jellyfish, the Sunfish

19. http://www.earthwindow.com/mola.html#