Transcript Types of Corals Types of Reefs

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Types of Corals
Types of Reefs
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Pillar (Digitate) Coral
• Upward cylinders
• Look like fingers or
cigars
• No secondary
branching
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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
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Elkhorn Coral
• Thick, sturdy, flat, antler-like branches
• Fast growing
• Survive in heavy
wave action
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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
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Encrusting Coral
• Grow flat instead of
up
• Adhere to rock
• Protected from
wave action
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Mushroom Coral
Mushroom shape
Flat or dome oval
Solitary
Unattached
Indo-Pacific waters
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Types of Reefs
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Fringing Reefs
• Most common
• Project seaward
from the shore
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Barrier Reefs
• Border
shorelines
• Separated from
land by lagoon
of open, often
deep water
land
barrier
fringe
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Atoll
• Fringe reef forms
• Volcanic island
subsides
• Usually circular
with central
lagoon
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Parts of the Reef
Determining Factors
Bottom topography
Depth
Wave action
Current
Temperature
Light
Sediment
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Reef Flat Zone
Sheltered side of reef
Variable depth: exposed at low tide
Seagrass beds
Substrate: loose sand and coral
Encrusting and filament algae common
Variable temp and salinity
Protected from waves
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Reef Crest
Highest point on reef
Severe wave action: little live coral
Exposed at low tide
Stout branching coral
Small animals live protected among nooks and crannies
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Fore Reef
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