Cnidarians are a phylum of aquatic animals that include jellyfish, corals, sea anemones and hydroids. They live in oceans around the world, from the surface waters to the deep sea. Cnidarians have two life stages - a free-swimming medusa stage and a stationary polyp stage, where they are attached to a surface. Their life cycle often involves both a medusa and polyp form.

1. Formosa Lan Biology 4 period 3/31/2010 Cnidarians

2. What is a Cnidarians? The phylum contains thousands of living species worldwide. The cnidarians include : , . &quot;http://www.factmonster.com/ce6/.html.&quot; The Columbia Electronic Encyclopedia. © 1994, 2000-2006, on Fact Monster. © 2000–2007 Pearson Education, publishing as Fact Monster. 31 Mar. 2010 <http://www.factmonster.com/ce6/sci/A0839602.html>. Many thousands of cnidarians species live in the oceans, from the surface to the bottom. Hydroids , Anemones Corals Jellyfish ,

3. The free-swimming &quot;jellyfish&quot; stage in a cnidarians life cycle. The other stage is the sedentary “ polyp &quot; stage. A sessile, or nonmotile, organism. polyps are the sea anemone and the freshwater hydra. Polyp Medusa

4. Anthozona CLASSES Scyphozoans hydrozoa

5. Life Cycle

6. Stan & Debbie Hauter. &quot;Dori Corell's Pink Tube Anemone.&quot; http://z.about.com/d/saltaquarium/1/0/j/W/1/dcorellpinkanemone_600.jpg Jellyfish Pictures. Photograph. http://www.funny-potato.com/jellyfish.html Hedgehog Hydroid Photo, Hydractinia Milleri.“ http://www.oceanlight.com/spotlight.php?img=1036 The Coral Kingdom Collection/NOAA. Nationalgeographic- Coral Anthozoa. http://s.ngeo.com/wpf/media-live/photos/000/005/cache/coral-reef_507_600x450.jpg The Columbia Encyclopedia Sixth Edition. http://www.ville-ge.ch/mhng/hydrozoa/intro/topology.gif Aurelia Life Cycle . Web. http://cas.bellarmine.edu/tietjen/images/myaurelia.gif Aiptasia Biology. By Www.berghia.net, INSTAR, 2010. Web <http://www.berghia.net/pics/IM004064aiptasia1.jpg>. The NOAA Photo Library -Scyphozoans - Jellyfish . Web. <http://earlham.edu/~meckehe/scyphozoajellyfish.htm>. Academic Dictionaries and Encyclopedias -Hydrozoa . Web. <http://en.academic.ru/dic.nsf/enwiki/217443>. Bibliography