1. Types of Corals Types of Reefs
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Types of Corals Types of Reefs

2. Pillar (Digitate) Coral
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Pillar (Digitate) Coral
Upward cylinders
Look like fingers or
cigars
No secondary branching

3. Table Corals Plate like with polyps extending upward
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Table Corals
Plate like with polyps extending upward
Increased surface area for photosynthesis
Easier for tentacles to capture zooplankton

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Branching Coral
Primary and secondary branches
Resemble bushes

5. Elkhorn Coral Thick, sturdy, flat, antler-like branches Fast growing
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Thick, sturdy, flat, antler-like branches
Fast growing
Survive in heavy
wave action

6. Foliase Coral Whorl-like pattern Look like flower petals
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Foliase Coral
Whorl-like pattern
Look like flower petals
Increased surface area
Provide shelter for animals between “petals”

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Massive Corals
Ball/boulder shape
Very sturdy
Very slow growing

8. Encrusting Coral Grow flat instead of up Adhere to rock
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Encrusting Coral
Grow flat instead of up
Adhere to rock
Protected from wave action

9. Mushroom Coral Mushroom shape Flat or dome oval Solitary Unattached
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Mushroom shape
Flat or dome oval
Solitary
Unattached
Indo-Pacific waters

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Types of Reefs

11. Fringing Reefs
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Most common
Project seaward from the shore

12. Barrier Reefs Border shorelines
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Barrier Reefs
Border shorelines
Separated from land by lagoon of open, often deep water
land
fringe
barrier

13. Atoll Fringe reef forms Volcanic island subsides
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Atoll
Fringe reef forms
Volcanic island subsides
Usually circular with central lagoon

14. Parts of the Reef Determining Factors Bottom topography Depth
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Determining Factors
Bottom topography
Depth
Wave action
Current
Temperature
Light
Sediment

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16. Reef Flat Zone 16/18 Sheltered side of reef Variable temp and salinity
Variable depth: exposed at low tide
Protected from waves
Seagrass beds
Substrate: loose sand and coral
Encrusting and filament algae common

17. Reef Crest 17/18 Exposed at low tide Highest point on reef
Severe wave action: little live coral
Stout branching coral
Small animals live protected among nooks and crannies

18. Fore Reef 18/18 Low tide mark to deep water
Deep channels between buttresses
Butresses: stabilize reef and dissipate wave action
Channels: drain reef debris & sediment to deeper water
Abundant O2 + hiding spaces = small fish
Small fish bring big fish! Yummy!
Deep dark water = sponges, & non-reef building coral