1. What would you do if you were stung by a jellyfish?

2. Cnidarians -Another very diverse group including: Jellyfish Anemones Hydroids Coral Box Jellyfish **Simplest organisms with a tissue level of organization!

3. Cnidarians 1) Radial Symmetry – Can be sliced evenly like slices of a pizza

4. Cnidarians 2) Main body composed of 2 layers – epidermis/gastrodermis The area between the 2 layers is a “jelly-like” substance known as the mesoglea. Epi = skin Gastro = digestive

5. Cnidarians 3) One of two body forms – polyp or medusa

6. Cnidarians 4) Nematocysts – specialized cells located on tentacles intended for capturing prey/stinging predators. http://www5.pbrc.hawaii.edu/pcrl/News&Videos.html

7. Cnidarians 5) Solitary or Colonial *Sometimes secrete calcium carbonate “base” to rest on.

8. Cnidarians Most cnidarian polyps can reproduce asexually. They are slow/sessile, so this is a means of recovering from attacks. Cnidarian medusae have a complex development, and can only regenerate lost tentacles. Reproduction 1)They cut a small piece of the glowing portion from “e”. 2) “a-d” shows the development of those cells. 3) “f” is what the cells grew into. VERY FAMOUS STEM CELL RESEARCH PROJECT

9. Cnidarians Other senses  ocelli = eyespots on edge of bell (only detect light). smell/taste = sensory receptors on bell and tentacles.

10. Cnidarians -Mouth = anus -Simple digestive system  tentacles pull food in and food is digested inside gastrodermis. Waste is expelled through the same hole that it came in. Their gut has several folds to increase surface area for absorption of food, very similar to our intestines. *Only in polyps* They contain mesenterial filaments. These can be extruded to “digest” other sessile organisms nearby.

11. Cnidarians Deadly Irukandji jellyfish. Very rare off the coasts of Australia, but extremely potent venom

12. Discovery Channel Documentary  http://video.google.com/videoplay?docid=- 5244772188533526164&ei=OZlDS4ntKJ7cqALW_tzTCA&q=irukandji&hl=en# http://video.google.com/videoplay?docid=- 5244772188533526164&ei=OZlDS4ntKJ7cqALW_tzTCA&q=irukandji&hl=en# Woman stung by jellyfish squirming due to immense pain all over body

13. Portuguese man-of-war http://www.wkrg.com/florida/article/portuguese_man_of_ war_invade_gulf_coast_beaches/12220/Jul-31-2008_12- 21-am/

14. What would you do if you were stung by a jellyfish?