2. Coral Reefs

3. Coral reefs are similar to rain forests in that they are complex and diverse

5. Coral Reefs Coral reefs are made of calcium carbonate CaCO 3 deposited by reef-building organisms like coral.

7. Coral Reefs Coral polyp is a sac like stage of a Cnidarian with mouth and tentacles on top.

8. Coral polyp

11. Coral Reefs What is a coral colony? “Founder” coral divides over and over so all are clones that have a connected digestion system and share a common nervous system. Touch one and they all respond.

12. Coral Colony cutaway

13. Coral Colony

14. Coral Reef What are zooxanthellae? Dinoflagellates that live within animal tissue Have symbiotic mutualistic relationships with organisms providing food and color They do photosynthesis and pass on some of the organic matter to the coral. Feed coral from inside. Enable coral to make CaCO 3 faster

16. zooxanthellae living in a mutualistic relationship with coral

17. Five Ways Coral Feed 1.Zooxanthellae are most important source of nutrition 2.Capture zooplankton with stinging nematocysts on tentacles 3.Capture zooplankton with mucus nets 4.Digest organic material outside the body with mesenterial filaments 5.Absorb DOM dissolved organic matter

18. Coral polyp

19. Stinging Nematocysts

21. mesenterial filaments

22. Encrusting Coralline Algae Deposit of CaCO 3 (limestone) add to structure of reef Forms algal ridge, block waves, prevents erosion Cements sediments in place,keeps reef from washing away Food source for fish

23. Encrusting Coralline Algae

25. algal ridge

26. Coral reproduction Sometimes asexual, cloning Some corals hermaphroditic….. Some separate sexes Have mass spawning ex. Great Barrier Reef between Oct- Nov Larva is called planula larva

27. Budding

29. coral spawning

31. Life cycle of a coral polyp

32. coral spawning

34. Conditions for reef growth Shallow clear water Good light Warm water- just right Stable salinity

35. Clear Water

36. Other Reef Builders: Oysters Polychete worms Shells of snails, clams, other mollusks, sea urchins, crustaceans, sponge.